prr.hec.gov.pkprr.hec.gov.pk/jspui/bitstream/123456789/7062/1/Waseem_Ahmed... · DECLARATION I hereby declare that contents of thesis, “Harvest maturity and post-harvest factors

HARVEST MATURITY AND POSTHARVEST FACTORS AFFECTING THE

SHELF LIFE AND QUALITY OF GRAPEFRUIT

By

WASEEM AHMED

Regd. No. 2002-ag-1892

M.Sc. (Hons.) Horticulture

A thesis submitted in the partial fulfillment of the requirements for the degree of

Doctor of Philosophy

in

Horticulture

Institute of Horticultural Sciences,

Faculty of Agriculture,

UNIVERSITY OF AGRICULTURE, FAISALABAD,

PAKISTAN

2015

DECLARATION

I hereby declare that contents of thesis, “Harvest maturity and post-harvest factors

affecting the shelf life and quality of grapefruit” are the product of my own research and

no part has been copied from any published source (except the references, standard

mathematical model/equations/formulate/protocols etc.). I further declare that this work has

not been submitted for award of any other diploma/degree. The university may take action if

the information provided is found inaccurate at any stage (in case of any default, the scholar

will be proceeded against as per HEC plagiarism policy).

WASEEM AHMED

(2002-ag-1892)

The Controller of Examinations,

University of Agriculture,

Faisalabad, Pakistan.

We the supervisory committee, certify that the contents and form of the thesis submitted by

Mr. Waseem Ahmad, Reg. No. 2002-ag-1892 have been found satisfactory and recommend

that it be processed for final the award of degree.

SUPERVISORY COMMITTEE

1. Supervisor ___________________________________

(Dr. Saeed Ahmad)

2. Member ___________________________________

(Dr. Aman Ullah Malik)

3. Member ___________________________________

(Dr. Rashid Ahmad)

OPENING

HE IS THE FIRST,

HE IS THE LAST HE IS THE MANIFEST

HE IS THE HIDDEN

&

HE KNOWS EVERY THING

HE BRINGS THE NIGHT INTO THE DAY

&

BRINGS THE DAY INTO THE NIGHT

&

HE KNOWS THE THOUGHTS OF THE HEARTS

S. Al-HADDID-385 (AL-QURAN)

Dedicated to

My Mother

My Father

My wife & sons

&

My Brothers

i

ACKNOWLEDGEMENTS

All the praises are credited to the sole creator of the entire universe ALMIGHTY

ALLAH, the Most Beneficent, the Most Merciful and the Most Compassionate, Who

granted me the power of vision and wisdom to unknot the mysteries of the universe in a

more systematic manner what people call it SCIENCE. And only by the grace of

ALLAH, I was capable to make this material contribution to already existing ocean of

knowledge. I invoke Allah’s blessings and peace for my beloved Prophet Hazrat

MOHAMMAD (Peace Be upon Him), who is eternally present torch of direction and

knowledge for humanity as a whole and whose honorable and spiritual teachings

enlightened my heart, soul and mind.

I desire to widen most sincere thanks and deep sense of obligations to my supervisor, Dr.

Saeed Ahmad, Associate Professor, Institute of Horticultural Sciences. This manuscript

has found its way to a significant close due to his energetic supervision, and masterly

advice.

I feel much happiness to utter the heartiest gratitude and sincere admiration to Dr. Aman

Uallah Mailk Professor, Institute of Horticultural Sciences, and member supervisory

committee for his generous guidance, kind behavior, cooperation and priceless

suggestions on this piece of work. I wish to record my heartfelt appreciation to Dr.

Rashid Ahmad, Professor, Department of Crop Physiology, member of supervisory

committee for his affectionate behavior and moral support throughout the course of my

studies.

I would be neglecting my duties if I failed to extend my admiration and appreciation to

Dr. Farooq Ahmed, Associate Professor (Department of Agronomy) for his untiring

help and moral support during my studies and for devoting time to reading the final

manuscript.

With deep sense of devotion, I wish to thank CH. M. Azhar (Director Postharvest

Research Centre Ayub Agriculture Research Institute, Faisalabad) Mr. Abdul

Rahim Khan Principal Investigator, Post-harvest Research Centre Ayub Agriculture

Research Institute, Faisalabad, Citrus Research Institute Sargodha Pakistan, for his

kind help and support during the research work. I am also thankful to Pomology Lab

staff, Shakil Zahid, Shakeel Latif and Muhammad Farhan Khalid for their prayers

and nice cooperation in lab work during the whole period of study.

I acknowledge with great sincerity the affection of my honorable friends especially Dr.

Imtiaz Hussain (my best friend), Dr. Iqbal Hussain, M. Arfan, H. Ijaz, Amanat, M.

Naveed and my MSc. Fellows for their friendly behavior, nice collaboration and help

they provided as and when needed.

Words do not come out easy for me to mention the feelings of obligations towards

affectionate parents. I am most earnestly appreciated to my Great Mother and Honorable

Father and my wife, his mother and father who support and help me, my cute sons

(Suleman and Ayan ) for the strenuous efforts made by them in enabling me to join the

higher ideals of life and also for their all kinds of support, patience and prayers they have

made for my success. I feel my proud privilege to mention the feelings of obligations

towards my brother Naeem Ahmed, Faheem Ahmed, Haleem Ahmed, Nadeem

Ahmed and Azeem Ahmed for their love, affection and prayers which enabled me to

acquire this long adhered aim.

I am also thankful to the Higher Education Commission, Government of Pakistan for

awarding me the financial assistance to achieve this goal.

Waseem Ahmed

ii

TABLE OF CONTENTS

Chapter ≠ Title Page ≠

Acknowledgements I

Table of contents Ii

List of tables Xi

List of figures Xiii

List of slides Xxii

List of symbols and abbreviations Xxiii

Abstract 1

1 INTRODUCTION 3

2 REVIEW OF LITERATURE 6

2.1 History and origin of grapefruit 6

2.2 Overview of grapefruit 6

2.3 Grapefruit cultivars 6

2.4 Nutritional Profile and health benefits of grapefruit 6

2.5 Phytochemicals in grapefruit 7

2.6 World grapefruit industry 7

2.7 Harvesting of grapefruit 7

2.8 Developmental structural and compositional changes in

grapefruit on tree 8

2.9 Quality changes during different harvesting dates of citrus fruits 9

2.10 Effects of harvesting maturity on Colour, total soluble solids

content and acidity 10

2.11 Effects of storage temperature on the quality changes of citrus 10

2.12 Storage effects on bioactive components 11

2.13 Postharvest losses and physiological disorders 11

2.14 Effects of pre storage hot water treatments on quality of fruit

during storage 11

2.15 Physiological disorders during storage 12

2.15.1 Introduction 12

2.15.2 Chilling Injury (CI) and its causes 13

2.15.3 Post-harvest treatments for reducing CI symptoms during

storage 14

2.16 Respiration and Juice quality changes during storage 14

2.17 Textural properties and fruit firmness 15

2.18 Wax coating 15

2.19 Fruit coatings and wax applications 15

2.20 Chitosan wax coating 16

2.21 Physicochemical changes during storage of grapefruit 16

2.22 Respiration rates changes during storage 17

2.23 Antioxidant activity and flavonoids changes 17

2.24 Role of Salicylic (SA) and Methyl Jasominate (Me JA) 18

3 MATERIAL AND METHODS 20

3.1 Experimental materials and site selection 21

3.1.1 Experiment-1 Effects of different harvesting dates on the

quality and the shelf life of grapefruit 21

3.1.1.1 Physical parameters 21

iii

3.1.1.1.1 Fruit diameter (mm) 21

3.1.1.1.2 Fruit weight (g) 21

3.1.1.1.3 Number of seeds per fruit 21

3.1.1.1.4 Peel weight (g) 21

3.1.1.1.5 Pulp weight (%) 21

3.1.1.1.6 Rag weight (%) 22

3.1.1.1.7 Juice weight (%) 22

3.1.1.1.8 Number of oil glands (per 180 mm2) 22

3.1.1.1.9 Number of segments 22

3.1.1.1.10 Fruit firmness (Nm²) 22

3.1.1.1.11 Pulp/peel ratio 22

3.1.1.2 Biochemical analysis of grapefruit 23

3.1.1.2.1 Juice pH 23

3.1.1.2.2 Total soluble solids (˚Brix) 23

3.1.1.2.3 Total titratable Acidity (%) 23

3.1.1.2.4 TSS/acid ratio 23

3.1.1.2.5 Ascorbic acid (mg/100 mL) 23

3.1.1.2.6 Sugars (total sugars, reducing and non-reducing sugars) 23

3.1.1.3 Phytochemical parameters 23

3.1.1.3.1 Total phenolic contents (mg GAE/100 g) 23

3.1.1.3.2 Total antioxidants (% DPPH inhibition) 24

3.1.1.3.3 Total flavonoids contents (mg CEQ/100 g) 24

3.1.1.3.4 Limonin contents (µg/mL) 24

3.1.1.3.5 Total pectin contents (mg/100 g) 25

3.1.1.3.6 Total carotenoids contents (mg/100g) 25

3.2.1

Experiment-2a Effects of cold storage and tree storage

relating to their quality and shelf life of grapefruit cv. Ray

Ruby

26

3.2.1.1 Fruit harvesting 26

3.2.1.2 Washing and cleaning the fruits 26

3.2.1.3.4 Storage conditions 27

3.2.1.3.5 Treatment layout 26

3.2.1.3.5.1 Physiological disorders 27

3.2.1.3.5.1 Weight loss in weight (%) 27

3.2.1.3.5.2 Chilling injury (%) 27

3.2.1.3.5.4 CO2 and Ethylene 27

3.2.1

Experiment-2b Effects of cold storage and tree storage

relating to their quality and shelf life of grapefruit cv.

Shamber

29

3.3.1

Experiment-3a. Comparison of hot water treatment and

fungicide against quality and the shelf life of grapefruit cv.

Ray Ruby

29


3.3.1.2 Washing and cleaning of fruits 29

3.3.1.3 Hot water treatment procedure 29

3.3.1.4 Fungicide applications after HWT 29

3.3.1.5 Storage conditions. 30

3.3.1.6 Experimental treatment layout 30

iv

3.3.1

Experiment-3b Comparison of hot water treatment and

fungicide against quality and the shelf life of grapefruit cv.

Shamber

30

3.4.1 Experiment-4a Effects of Wax Coating on the quality and

the Shelf life of grapefruit of Ray Ruby. 32



3.4.1.3 Fungicides applications 32

3.4.1.4 Preparation of wax coating 32

3.4.1.5 Application of wax coating 32

3.4.1.6 Treatments layout 33

3.4.1 Experiment-4b Effects of Wax Coating on the quality and

the Shelf life of grapefruit of Shamber. 33

3.5.1

Experiment-5a Effects of pre-harvest spray of salicylic (SA)

and Methyl Jasmonate (MeJA) on the chilling injury, decay

and phytochemicals during the storage in grapefruit cv. Ray

Ruby

33

3.5.1.1 Preparation of salicylic acid solution 33

3.5.1.2 Preparation of methyl jasmonate solution 33

3.5.1.3 Harvesting and storage 33


3.5.1.5. Treatments layout 34

3.5.1

Experiment-5b Effects of pre-harvest spray of salicylic (SA)

and Methyl Jasmonate (MeJA) on the chilling injury, decay

and phytochemicals during the storage in grapefruit cv.

Shamber

34

3.1.1.3.7 Organoleptic evaluation 40

3.1.1.3.8 Statistical analysis 41

4 RESULT AND DISUSSION 42

4.1 Experiment-1 Effects of different harvesting dates on the

quality and shelf life of grapefruit 42

4.1.1 Results 42

4.1.1.1 Physical parameters 42

4.1.1.1.1 Fruit weight (g) 42

4.1.1.1.2 Fruit diameter (mm) 42

4.1.1.1.3 Peel weight (g) 44

4.1.1.1.4 Rag weight (g) 44

4.1.1.1.5 Juice weight (g) 43

4.1.1.1.6 Number of seeds 46

4.1.1.1.7 Healthy seeds 47

4.1.1.1.8 Aborted seed 47

4.1.1.1.9 Oil glands (180 mm-2) 48

4.1.1.1.10 Fruit firmness (Nm2) 48

4.1.1.1.11 Pulp/peel ratio 49

4.1.1.1.12 Number of segments 49

4.1.1.2 Biochemical parameters 51

4.1.1.2.1 Total soluble solids (oBrix) 51

4.1.1.2.3 Total titratable acidity (%) 51

v

4.1.1.2.4 TSS/acidity ratio 52

4.1.1.2.5 Ascorbic acid (mg/100 g) 52

4.1.1.2.6 Total sugars (%) 54

4.1.1.2.7 Reducing sugars (%) 55

4.1.1.2.8 Non-reducing sugars (%) 57

4.1.1.3 Phytochemical parameters 57

4.1.1.3.1 Total phenolic contents (mg GAE/100 g) 57

4.1.1.3.2 Total antioxidants (% DPPH inhibition) 59

4.1.1.3.3 Total flavonoids (mg CEQ/100 g) 59

4.1.1.3.4 Total carotenoids (mg/100 g) 61

4.1.1.3.5 Total pectin contents (%) 61

4.1.1.3.6 Total limonin contents (µg/mL) 62

4.1.1.3.7 Total glycoside limonin contents (µg/mL) 60

4.1.2 Discussion 63

4.12.3 Conclusion 66

4.2

Experiment-1 (a) Effects of cold storage and tree storage

(delayed harvesting) relating to their quality and shelf life of

grapefruit cv. Ray Rub

67

4.2.1a Results 67

4.2.1.1a Biochemical parameters 67

4.2.1.1.1a pH of juice 67

4.2.1.1.2a Total soluble solids (oBrix) 67

4.2.1.1.3a Total titratable acidity (%) 69

4.2.1.1.4a TSS/acidity ratio 69

4.2.1.1.5a Ascorbic acid (mg/100 g) 71

4.2.1.1.6a Total sugar contents (%) 72

4.2.1.1.7a Reducing sugar contents (%) 72

4.2.1.1.8a Non-reducing sugar contents (%) 74

4.2.1.2a Phytochemical parameters 74

4.2.1.2.1a Total phenolic contents (mg GAE/100 g) 74

4.2.1.2.2a Total antioxidants (% DPPH inhibition) 75

4.2.1.2.3a Total flavonoids contents (mg CEQ/100 g) 76

4.2.1.2.4a Total carotenoids (mg/100 g) 76

4.2.1.2.5a Total limonin contents (µg/mL) 78

4.2.1.3a Physiological parameters 79

4.2.1.3.1a Chilling injury (%) 79

4.2.1.3.2a Fruit rot (%) 79

4.2.1.3.3a Fruit weight loss (%) 81

4.2.1.3.4a CO2 (ml kghr-1) 81

4.2.1.3.5a Ethylene (µL kghr-1) 83

4.2.1.4a Organoleptic parameters 84

4.2.1.4.1a Color score 84

4.2.1.4.2a Texture score 84

4.2.1.4.3a Taste score 86

4.2.1.4.4a Sourness score 86

4.2.1.4.5a Sweetness score 87

4.2.1.4.6a Overall quality score 87

4.2 Experiment-1 (b) Effects of cold storage and tree storage 89

vi

(delayed harvesting) relating to their quality and shelf life of

grapefruit cv. Shamber

4.2.1b Results 89

4.2.1.1b Biochemical parameters 89

4.2.1.1.1b pH of juice 89

4.2.1.1.2b Total soluble solids (oBrix) 89

4.2.1.1.3b Total titratable acidity (%) 91

4.2.1.1.4b TSS/acidity ratio 93

4.2.1.1.5b Ascorbic acid (mg/100 g) 93

4.2.1.1.6b Total sugar contents (%) 94

4.2.1.1.7b Reducing sugar contents (%) 94

4.2.1.1.8b Non-reducing sugar contents (%) 97

4.2.1.2b Phytochemical parameters 97

4.2.1.2.1b Total phenolic contents (mg GAE/100 g) 97

4.2.1.2.2b Total antioxidants (% DPPH inhibition) 97

4.2.1.2.3b Total flavonoids contents (mg CEQ/100 g) 99

4.2.1.2.4b Total carotenoids (mg/100 g) 99

4.2.1.2.5b Total limonin contents (µg/mL) 101

4.2.1.3b Physiological parameters 102

4.2.1.3.1b Chilling injury (%) 102

4.2.1.3.2b Fruit rot (%) 104

4.2.1.3.3b Fruit weight loss (%) 104

4.2.1.3.4b CO2 (ml kghr-1) 104

4.2.1.3.5b Ethylene (µL kghr-1) 106

4.2.1.4b Organoleptic parameters 107

4.2.1.4.1b Color score 107

4.2.1.4.2b Texture score 107

4.2.1.4.3b Taste score 109

4.2.1.4.4b Sourness score 109

4.2.1.4.5b Sweetness score 109

4.2.1.4.1b Overall quality score 111

4.2.2 (a, b) Discussion 112

4.2.3 (a, b) Conclusion 116

4.3

Experiment-1 (a) Comparison of hot water and fungicide

treatments on the quality and shelf life of grapefruit cv. Ray

Ruby 117


4.3.1.1.1a pH of juice 117





4.3.1.1.6a Total sugars (%) 122

4.3.1.1.7a Reducing sugars (%) 123

4.3.1.1.8a Non-reducing sugars (%) 124

4.3.1.2a. Phytochemical parameters 126


4.3.1.2.2a Total antioxidants activities (% DPPH inhibition) 126

vii


4.3.1.2.4a Total carotenoids contents (mg/100 g) 127




4.2.1.3.2a Fruit rot (%) 130


4.2.1.3.4a Heat production (Kcal metric ton/day) 132








4.3

Experiment-1 (b) Comparison of hot water and fungicide

treatments on the quality and shelf life of grapefruit cv.

Shamber

140

4.3.1b Results 140


4.3.1.1.1b pH of juice 140





4.3.1.1.6b Total sugars (%) 145

4.3.1.1.7b Reducing sugars (%) 146

4.3.1.1.8b Non-reducing sugars (%) 147



4.3.1.2.2b Total antioxidants activities (%DPPH inhibition) 149


4.3.1.2.4b Total carotenoids contents (mg/100 g) 150




4.2.1.3.2b Fruit rot (%) 153


4.2.1.3.4b Heat production (Kcal metric ton/day) 155










viii

4.4 Experiment-1 (a) Effects of wax coating on the quality and

shelf of grapefruit cv. Ray Ruby 165

4.4.1a Results 165


4.4.1.1.1a pH of juice 165





4.4.1.1.6a Total sugars (%) 170





4.4.1.2.2a Total antioxidants activities (%DPPH inhibition) 174



4.4.1.2.5a Total limonin contents (µg\mL) 178


4.4.1.3.2a Fruit rot (%) 179


4.4.1.3.4a CO2 (ml kghr-1) 181

4.4.1.3.5a Ethylene (µL kghr-1) 183







4.4.1b Overall quality score 188

4.4 Experiment-1 (b) Effects of wax coating on the quality and

shelf of grapefruit cv. Shamber 190

Results 190


4.4.1.1.1b pH of juice 190





4.4.1.1.6b Total sugars (%) 195

4.4.1.1.7b Reducing sugars (%) 195

4.4.1.1.8b Non-reducing sugars (%) 197



4.4.1.2.2b Total antioxidants activities (% DPPH inhibition) 198



4.4.1.2.5b Total limonin contents (µg\mL) 202

ix



4.4.1.3.2b Fruit rot (%) 203


4.4.1.3.4b CO2 (ml kghr-1) 205

4.4.1.3.5b Ethylene (µL kghr-1) 207







4.2.1.4.6b Overall quality scores 213



4.5

Experiment-1 (a) Effects of pre-harvest spray of salicylic

(SA) and Methyl Jasmonate (MeJA) on the chilling injury,

decay and phytochemicals during the storage of grapefruit

cv. Ray Ruby

219

4.5.1.1.6a Results 219


4.5.1.1.1a pH of juice 219





4.5.1.1.6a Total sugars (%) 224





4.5.1.2.2a Total antioxidants activities (% DPPH inhibition) 247






4.5.1.3.2a Fruit rot (%) 235

4.5.1.4a Fruit weight loss (%) 235


4.5.1.4.1a Colour score 236






4.5 Experiment-1 (b). Effects of pre-harvest spray of salicylic

(SA) and Methyl Jasmonate (MeJA) on the chilling injury, 243

x

decay and phytochemicals during the

4.5.1b Results 243


4.5.1.1.1b pH of juice 243





4.5.1.1.6a Total sugars (%) 248





4.5.1.2.2b Total antioxidants activities (%DPPH inhibition) 251






4.5.1.3.2b Fruit rot (%) 257










4.5.3 (a,b) Conclusion 272

5 General discussion, conclusions, Recommendations 273

5.1 General discussion 273

5.2 Conclusions 279

5.3 Recommendations 280

LITERATURE CITED 281

xi

LIST OF TABLES

Table ≠ Title Page ≠

4.1 Effects of different harvesting dates and varieties on the fruit

Weight (g) of Ray Ruby and Shamber fruits.

43


diameter (mm) of Ray Ruby and Shamber fruits.

43


peel weight (g) of Ray Ruby and Shamber fruits.

45

4.4 Effects of different harvesting dates and varieties on the fruit rag

weight (g) of Ray Ruby and Shamber fruits.

45


juice weight (g) of Ray Ruby and Shamber fruits.

46

4.6 Effects of different harvesting dates and varieties on the number

of seeds in Ray Ruby and Shamber fruits.

46


of healthy seeds in Ray Ruby and Shamber fruits.

47


of aborted seeds in Ray Ruby and Shamber fruits.

47

4.9 Effects of different harvesting dates and varieties on the oil

glands (180 mm-2) in Ray Ruby and Shamber fruits.

48

4.10 Effects of different harvesting dates and varieties on the firmness

(Nm2) in Ray Ruby and Shamber fruits.

49

4.11 Effects of different harvesting dates and varieties on the

peel/pulp ratio in Ray Ruby and Shamber fruits.

50


of segments ratio in Ray Ruby and Shamber fruits.

50

4.13 Effects of different harvesting dates and varieties on the pH of

juice in Ray Ruby and Shamber fruits.

51

4.14 Effects of different harvesting dates and varieties on the total

soluble solids (oBrix) in Ray Ruby and Shamber fruits.

52


titratable acidity (%) in Ray Ruby and Shamber fruits.

53


TSS/acidity ratio in Ray Ruby and Shamber fruits.

53

4.17 Effects of different harvesting dates and varieties on the ascorbic

acid contents (mg/100 g) in Ray Ruby and Shamber fruits.

54


sugars (%) in Ray Ruby and Shamber fruit

55


reducing sugar (%) in Ray Ruby and Shamber fruits.

56

4.20 Effects of different harvesting dates and varieties on the non-

reducing sugars (%) in Ray Ruby and Shamber fruits.

56


phenolic contents (mg GAE/100 g) in Ray Ruby and Shamber

fruits.

58


antioxidants activities (% DPPH inhibition) in Ray Ruby and

Shamber fruits.

58

xii


flavonoids contents (mg CEQ/100 g) in Ray Ruby and Shamber

fruits.

60


carotenoids (mg/100 g) in Ray Ruby and Shamber fruits.

60


pectin contents (%) in Ray Ruby and Shamber fruits.

61


limonoids contents (µg/L) in Ray Ruby and Shamber fruits.

62


glycoside limonin contents (µg/mL) in Ray Ruby and Shamber

fruits.

63

xiii

LIST OF FIGURES

Figure ≠ Title Page ≠

4.28a Effects of cold storage (CS) and tree storage (TS) on pH in fruits of

Ray Ruby analyzed after 30, 60 and 90 days periods.

68

4.29a Effects of cold storage (CS) and tree storage (TS) on total soluble

solids (oBrix) in fruits of Ray Ruby analysed after 30, 60 and 90

days periods.

68

4.30a Effects of cold storage (CS) and tree storage (TS) on total titratable

acidity (%) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

70

4.31a Effects of cold storage (CS) and tree storage (TS) on TSS/acidity

ratio in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

70

4.32a Effects of cold storage (CS) and tree storage (TS) on ascorbic acid

contents (mg/100 g) in fruits of Ray Ruby analysed after 30, 60 and

90 days periods.

71

4.33a Effects of cold storage (CS) and tree storage (TS) on total sugar

contents (%) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

73

4.34a Effects of cold storage (CS) and tree storage (TS) on reducing sugar

contents (%) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

73

4.35a Effects of cold storage (CS) and tree storage (TS) on non-reducing

sugar contents (%) in fruits of Ray Ruby analysed after 30, 60 and

90 days periods.

74

4.36a Effects of cold storage (CS) and tree storage (TS) on total phenolic

contents (mg GAE/100 g) in fruits of Ray Ruby analysed after 30,

60 and 90 days periods.

75

4.37a Effects of cold storage (CS) and tree storage (TS) on total

antioxidants activities (% DPPH inhibition) in fruits of Ray Ruby

analysed after 30, 60 and 90 days periods.

76


flavonoids contents (mg CEQ/100 g) in fruits of Ray Ruby analysed

after 30, 60 and 90 days periods.

77


carotenoids (mg/100 g) in fruits of Ray Ruby analysed after 30, 60

and 90 days periods.

78

4.40a Effects of cold storage (CS) and tree storage (TS) on total limonin

contents (µg/mL) in fruits of Ray Ruby analysed after 30, 60 and 90

days periods.

79

4.41a Effects of cold storage (CS) and tree storage (TS) on chilling injury

(%) in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

80

4.42a Effects of cold storage (CS) and tree storage (TS) on fruit rot (%) in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

80

4.43a Effects of cold storage (CS) and tree storage (TS) on weight loss

(%) in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

82

4.44a Effects of cold storage (CS) and tree storage (TS) on CO2 (ml kghr-

1) in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

83

xiv

4.45a Effects of cold storage (CS) and tree storage (TS) on ethylene (µL

kghr-1) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

83

4.46a Effects of cold storage (CS) and tree storage (TS) on color score in

fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

85

4.47a Effects of cold storage (CS) and tree storage (TS) on texture score

in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.

85

4.48a Effects of cold storage (CS) and tree storage (TS) on taste score in


86

4.49a Effects of cold storage (CS) and tree storage (TS) on sourness score


87

4.50a Effects of cold storage (CS) and tree storage (TS) on sweetness

score in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

88

4.51a Effects of cold storage (CS) and tree storage (TS) on overall quality

score in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.

88

4.52b Effects of cold storage (CS) and tree storage (TS) on pH in fruits of

Shamber analysed after 30, 60 and 90 days periods.

90

4.53b Effects of cold storage (CS) and tree storage (TS) on TSS (oBrix) in

fruits of Shamber analysed after 30, 60 and 90 days periods.

90

4.54b Effects of cold storage (CS) and tree storage (TS) on titratable

acidity (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.

92

4.55b Effects of cold storage (CS) and tree storage (TS) on TSS/acidity

ratio in fruits of Shamber analysed after 30, 60 and 90 days periods.

92

4.56b Effects of cold storage (CS) and tree storage (TS) on ascorbic acid

contents (mg/100 g) in fruits of Shamber analysed after 30, 60 and

90 days periods.

93

4.57b Effects of cold storage (CS) and tree storage (TS) on total sugar

contents (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.

95

4.58b Effects of cold storage (CS) and tree storage (TS) on reducing sugar

contents (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.

95

4.59b Effects of cold storage (CS) and tree storage (TS) on non-reducing

sugar contents (%) in fruits of Shamber analysed after 30, 60 and 90

days periods.

96

4.60b Effects of cold storage (CS) and tree storage (TS) on total phenolic

contents (mg GAE/100 g) in fruits of Shamber analysed after 30, 60


98

4.61b Effects of cold storage (CS) and tree storage (TS) on total

antioxidants activities (%DPPH inhibition) in fruits of Shamber


98


flavonoids contents (mg CEQ/100 g) in fruits of Shamber analysed


100


carotenoids contents (mg/100 g) in fruits of Shamber analysed after

100

xv

30, 60 and 90 days periods.

4.64b Effects of cold storage (CS) and tree storage (TS) on total limonin

contents (µg/mL) in fruits of Shamber analysed after 30, 60 and 90

days periods.

101

4.65b Effects of cold storage (CS) and tree storage (TS) on chilling injury

(%) in fruits of Shamber analysed after 30, 60 and 90 days periods.

103

4.66b

Effects of cold storage (CS) and tree storage (TS) on fruit rot (%) in


103

4.67b Effects of cold storage (CS) and tree storage (TS) on fruit weight

loss (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.

105

4.68b Effects of cold storage (CS) and tree storage (TS) on CO2 (ml kghr-

1) in fruits of Shamber analysed after 30, 60 and 90 days periods.

105

4.69b Effects of cold storage (CS) and tree storage (TS) on ethylene (µL

kghr-1) in fruits of Shamber analysed after 30, 60 and 90 days

periods.

106

4.70b Effects of cold storage (CS) and tree storage (TS) on color score in


108

4.71b Effects of cold storage (CS) and tree storage (TS) on texture score

in fruits of Shamber analysed after 30, 60 and 90 days periods.

108

4.72b Effects of cold storage (CS) and tree storage (TS) on taste score in


110

4.73b Effects of cold storage (CS) and tree storage (TS) on sourness score


110

4.74b Effects of cold storage (CS) and tree storage (TS) on sweetness

score in fruits of Shamber analysed after 30, 60 and 90 days periods.

111

4.75b Effects of cold storage (CS) and tree storage (TS) on overall quality

score in fruits of Shamber analysed after 30, 60 and 90 days periods.

112

4.76 Effects of hot water treatments and fungicides on pH during storage

at (8ºC)

117

4.77a Effects of hot water treatments and fungicides on TSS during

storage at (8ºC)

119

4.78a Effects of hot water treatments and fungicides on TA during storage

at (8ºC)

120

4.79a Effects of hot water treatments and fungicides on TSS/acid during

storage at (8ºC)

121

4.80a Effects of hot water treatments and fungicides on ascorbic acid

contents (mg/100 g) during storage at (8ºC)

122

4.81a Effects of hot water treatments and fungicides on total sugar

contents (%) during storage at 8oC.

124

4.82a Effects of hot water treatments and fungicides on reducing sugar


125

4.83a Effects of hot water treatments and fungicides on non-reducing

sugar contents (%) during storage at 8oC.

125

4.84a Effects of hot water treatments and fungicides on total phenolic

contents (mg GAE/100 g during storage at 8oC.

126

4.85a Effects of hot water treatments and fungicides on total antioxidants

activities (% DPPH inhibition) during storage at 8oC.

127

4.86a Effects of hot water treatments and fungicides on total flavonoids 128

xvi

contents (mg CEQ/100 g) during storage at 8oC.

4.87a Effects of hot water treatments and fungicides on total carotenoids

contents (mg/100 g) during storage at 8oC.

128

4.88a Effects of hot water treatments and fungicides on total limonin

contents (µg/mL) during storage at 8oC.

129

4.89a Effects of hot water treatments and fungicides on chilling injury (%)

during storage at 8oC.

131

4.90a Effects of hot water treatments and fungicides on fruit rot (%)


131

4.91a Effects of hot water treatments and fungicides on weight loss during

storage at 8oC.

132

4.92a Effects of hot water treatments and fungicide on heat production

(Kcal metric ton/day) during storage at 8oC.

133

4.93a Effects of hot water treatments and fungicides on color score


134

4.94a Effects of hot water treatments and fungicides on texture score


135

4.95a Effects of hot water treatments and fungicides on taste score during

storage at 8oC.

136

4.96a Effects of hot water treatments and fungicides on sourness score


137

4.97a Effects of hot water treatments and fungicides on sweetness during

storage at 8oC.

138

4.98a Effects of hot water treatments and fungicides on overall quality

score during storage at 8oC.

139

4.99b Effects of hot water treatments and fungicides on pH during storage

at 8oC.

141

4.100b Effects of hot water treatments and fungicides on TSS (oBrix)


142

4.101b Effects of hot water treatments and fungicides on acidity (%) during

storage at 8oC.

143

4.102b Effects of hot water treatments and fungicides on TSS/acidity


144

4.103b Effects of hot water treatments and fungicides on ascorbic acid


145

4.104b Effects of hot water treatments and fungicides on total sugar


146

4.105b Effects of hot water treatments and fungicides on reducing sugar


147

4.106b Effects of hot water treatments and fungicides on non-reducing


148

4.107b Effects of hot water treatments and fungicides on total phenolic

contents (mg GAE/100 g) during storage at 8oC.

149

4.108b Effects of hot water treatments and fungicides on total antioxidants

activities (%DPPH inhibition during storage at 8oC.

150

4.109b Effects of hot water treatments and fungicides on total flavonoids


151

4.110b Effects of hot water treatments and fungicides on total carotenoids

contents (mg/100 g) during storage 8oC.

151

xvii

4.111b Effects of hot water treatments and fungicides on total limonin


152

4.112b Effects of hot water treatments and fungicides on chilling injury (%)


153

4.113b Effects of hot water treatments and fungicides on rot (%) during

storage at 8oC.

154

4.114b Effects of hot water treatments and fungicides on weight loss

(%)during storage at 8oC.

155

4.115b Effects of hot water treatments and fungicides on heat production

(Kcal metric ton/day) during storage at 8oC.

156

4.116b Effects of hot water treatments and fungicides on color score in

fruits during storage at 8oC.

157

4.117b Effects of hot water treatments and fungicides on texture score in


157

4.118b 4.3.1.4.3b. Effects of hot water treatments and fungicides on taste


159

4.119b Effects of hot water treatments and fungicides on sourness score


159

4.120b Effects of hot water treatments and fungicides on sweetness score


160

4.121b Effects of hot water treatments and fungicides on overall quality


161

4.122a Effects of wax coating treatments on pH during storage (8oC) in

grapefruit cv. Ray Ruby.

166

4.123a Effects of wax coating treatments on TSS (oBrix) during storage

(8oC) in grapefruit cv. Ray Ruby.

166

4.124a Effects of wax coating treatments on total titratable acidity (%)

during storage (8oC) in grapefruit cv. Ray Ruby.

168

4.125a Effects of wax coating treatments on TSS/acidity ratio during

storage (8oC) in grapefruit cv. Ray Ruby.

168

4.126a Effects of wax coating treatments on ascorbic acid contents (mg/100

g) during storage (8oC) in grapefruit cv. Ray Ruby.

169

4.127a Effects of wax coating treatments on total sugar contents (%) during

storage (8oC) in grapefruit Ray Ruby.

171

4.128a Effects of wax coating treatments on reducing sugar contents (%)

during storage (8oC) in grapefruit cv. of Ray Ruby.

171

4.129a Effects of wax coating treatments on non-reducing sugar contents

(%) during storage (8oC) in grapefruit Ray Ruby.

173

4.130a Effects of wax coating treatments on total phenolic contents (mg

GAE/100 g) during storage (8oC) in grapefruit cv. Ray Ruby.

174

4.131a Effects of wax coating treatments on total antioxidants activities

(%DPPH inhibition) during storage (8oC) in grapefruit cv. Ray

Ruby

175

4.132a Effects of wax coating treatments on total flavonoids contents (mg

CEQ/100 g) during storage (8oC) in grapefruit cv. Ray Ruby.

177

4.133a Effects of wax coating treatments on total carotenoids contents

(mg/100 g) during storage (8oC) in grapefruit cv. Ray Ruby.

177

4.134a Effects of wax coating treatments on total limonin contents (µg/mL)

during storage (8oC) in grapefruit cv. of Ray Ruby.

178

xviii

4.135a Effects of wax coating treatments on chilling injury (%) during

storage (8oC) in grapefruit cv. of Ray Ruby.

180

4.136a Effects of wax coating treatments on fruit rot (%) during storage


180

4.137a Effects of wax coating treatments on weight loss (%) during storage


182

4.138a Effects of wax coating treatments on CO2 (ml kghr-1) during storage


182

4.139a Effects of wax coating treatments on ethylene (µL kghr -1) during


183

4.140a Effects of wax coating treatments on color score during storage


185

4.141a Effects of wax coating treatments on texture score during storage


185

4.142a Effects of wax coating treatments on taste score during storage

(8oC) in grapefruit in Ray Ruby.

187

4.143a Effects of wax coating treatments on sourness score during storage


187

4.144a Effects of wax coating treatments on sweetness score during storage


189

4.145a Effects of wax coating treatments on overall quality score during


189

4.146b Effects of wax coating treatments on pH during storage (8oC)

ingrapefruit cv. Shamber.

191

4.147b Effects of wax coating treatments on TSS (oBrix) during storage

(8oC) in grapefruit cv. Shamber.

191

4.148b Effects of wax coating treatments on total titratable acidity (%)

during storage (8oC) in grapefruit cv. Shamber.

193

4.149b Effects of wax coating treatments on TSS/acidity ratio during

storage (8oC) in grapefruit cv. Shamber.

193

4.150b Effects of wax coating treatments on ascorbic acid contents (mg/100

g) during storage (8oC) in grapefruit cv. Shamber.

194

4.151b Effects of wax coating treatments on total sugar contents (%) during


196

4.152b Effects of wax coating treatments on reducing sugar contents (%)


196

4.154a Effects of wax coating treatments on total phenolic contents (mg

GAE/100 g) during storage (8oC) in grapefruit cv. Shamber.

197

4.155b Effects of wax coating treatments on total antioxidants activities

(%DPPH inhibition) during storage (8oC) in grapefruit cv. Shamber.

199

4.156b Effects of wax coating treatments on total flavonoids contents (mg

CEQ/100 g) during storage (8oC) in grapefruit cv. Shamber.

201

4.157b Effects of wax coating treatments on total carotenoids contents

(mg/100 g) during storage (8oC) in grapefruit cv. Shamber.

201

4.158b Effects of wax coating treatments on total limonin contents (µg/mL)


202

4.159b Effects of wax coating treatments on chilling injury (%) during


204

4.160b Effects of wax coating treatments on fruit rot (%) during storage 204

xix


4.161b Effects of wax coating treatments on weight loss (%) during storage


206

4.162b Effects of wax coating treatments on CO2 (mkghr-1) during storage


206

4.163b Effects of wax coating treatments on ethylene (µL kghr -1) during


207

4.164b Effects of wax coating treatments on color score during storage


209

4.165b Effects of wax coating treatments on texture score during storage


209

4.166b Effects of wax coating treatments on taste score during storage


211

4.167b Effects of wax coating treatments on sourness score during storage

(8oC) in grapefruit in Shamber.

212

4.168b Effects of wax coating treatments on sweetness score during storage


212

4.169b Effects of wax coating treatments on overall quality score during


213

4.170a Effects of pre-harvest spray of salicylic acid (SA) and methyl

jasmonate (MeJA) on pH during storage (8oC) in the fruits of Ray

Ruby.

220


jasmonate (MeJA) on TSS (oBrix) during storage (8oC) in the fruits

of Ray Ruby.

221


jasmonate (MeJA) on total titratable acidity (%) during storage

(8oC) in the fruits of Ray Ruby.

222


jasmonate (MeJA) on TSS/acidity ratio during storage (8oC) in the

fruits of Ray Ruby.

223


jasmonate (MeJA) on ascorbic acid contents (mg/100 g) during

storage (8oC) in the fruits of Ray Ruby.

224


jasmonate (MeJA) on total sugar contents (%) during storage (8oC)

in the fruits of Ray Ruby.

225


jasmonate (MeJA) on reducing sugar contents (%) during storage


226


jasmonate (MeJA) on non-reducing sugar contents (%) during


227


jasmonate (MeJA) on total phenolic contents (mg GAE/100 g)

during storage (8oC) in the fruits of Ray Ruby.

228


jasmonate (MeJA) on total phenolic contents (%DPPH inhibition)


229

xx


jasmonate (MeJA) on total flavonoids contents (mg CEQ/100 g)


231


jasmonate (MeJA) on total carotenoids contents (mg/100 g) during


131


jasmonate (MeJA) on total limonin contents (µg/mL) during storage


232

4.183a Effects of pre-harvest spray of salicylic acid (SA) and methy

jasmonate (MeJA) on chilling injury (%) during storage (8oC) in the

fruits of Ray Ruby.

234


jasmonate (MeJA) on fruit rot (%) during storage (8oC) in the fruits

of Ray Ruby.

234


jasmonate (MeJA) on weight loss (%) during storage (8oC) in the

fruits of Ray Ruby.

235


jasmonate (MeJA) on color score during storage (8oC) in the fruits

of Ray Ruby.

237


jasmonate (MeJA) on texture score during storage (8oC) in the fruits

of Ray Ruby.

237


jasmonate (MeJA) on taste score during storage (8oC) in the fruits

of Ray Ruby.

239


jasmonate (MeJA) on sourness score during storage (8oC) in the

fruits of Ray Ruby.

239


jasmonate (MeJA) on sweetness score during storage (8oC) in the

fruits of Ray Ruby.

241


jasmonate (MeJA) on overall quality score during storage (8oC) in

the fruits of Ray Ruby.

242

4.192b Effects of pre-harvest spray of salicylic acid (SA) and methyl

jasmonate (MeJA) on pH during storage (8oC) in the fruits of

Shamber.

244


jasmonate (MeJA) on TSS (oBrix) during storage (8oC) in the fruits

of Shamber.

244



(8oC) in the fruits of Shamber.

246


jasmonate (MeJA) on TSS/acidity ratio during storage (8oC) in the

fruits of Shamber.

246

4.196b Effects of pre-harvest spray of salicylic acid (SA) and methyl 247

xxi


storage (8oC) in the fruits of Shamber.


jasmonate (MeJA) on total sugar contents (%) during storage (8oC)

in the fruits of Shamber.

248


jasmonate (MeJA) on reducing sugar contents (%) during storage


250



storage (8oC) in the fruits of Shamber

250



during storage (8oC) in the fruits of Shamber.

252


jasmonate (MeJA) on total antioxidants activities (%DPPH

inhibition) during storage (8oC) in the fruits of Shamber.

252




253


jasmonate (MeJA) on total carotenoids contents (mg/100 g) during


254


jasmonate (MeJA) on Total limonin contents (µg/mL) during

storage (8oC) in the fruits of Shamber

256


jasmonate (MeJA) on chilling injury (%) during storage (8oC) in the

fruits of Shamber

257


jasmonate (MeJA) on fruit rot (%) during storage (8oC) in the fruits

of Shamber

258



fruits of Shamber.

259


jasmonate (MeJA) on color score during storage (8oC) in the fruits

of Shamber.

260


jasmonate (MeJA) on texture score during storage (8oC) in the fruits

of Shamber.

261


jasmonate (MeJA) on taste score during storage (8oC) in the fruits

of Shamber.

262



fruits of Shamber.

263



265

xxii

fruits of Shamber.


jasmonate (MeJA) on overall quality score during storage (8oC) in

the fruits of Shamber.

265

LIST OF SLIDE

Slide ≠ Title Page ≠

Slide.1 Ray Ruby 20

Slide.2 Shamber 20

Slide.3 Fruit stored at 8°C after 90 days of storage for both cultivars (Ray

Ruby and Shamber)

28

Slide.4 Fruit stored at 6°C after 90 days of storage for both cultivars (Ray

Ruby and Shamber)

28

Slide.5 Hot treatment of grapefruit and analyzed after 90 storage 31

Slide.6 Preparation of (SA and Me JA) and spray ahead before 15 days of

harvesting of both cultivars

35

Slide.7 Effects of SA (12mM) on quality and shelf life of Ray Ruby after

90 days storage

36

Slide.8 Effects of Me JA (5mM) on the quality and shelf life of Shamber

after 90 days storage

37

Slide.9 Fruits developed fruit Colour after 90 days of storage for both

cultivars at 8°C by application of both chemicals

38

Slide.10 Decay and chilling injury rating scale during storage of grapefruit 39

xxiii

LIST OF SYMBOLS AND ABBREVIATIONS

Abbreviation Description

A Absorbance

@ At the rate of

AA Abscisic acid

AARI Ayub Agricultural Research Institute

Ca Calcium

Ca+2 Calcium ions

CEQ Catechin equivalents

cm Centimeter

CRD Completely randomized design

CS Cold storage

cv Cultivar (s)

DAS Days after storage

DDH2O Double distilled water

o Degree

oC Degree Celsius

DPPH 2, 2, diphenyl-1-picrylhydrazyl

ELISA Enzyme-linked immunosorbent assay

C2H2 Ethylene

et al. et alia

FAO Food and Agriculture Organization

FC Folin-Ciocalteu

g Gram (s)

GAE Gallic acid equillents

GOP Government of Pakistan

> Greater than

h Hour

ha Hectare

HP Heat production

HW Hot water

HWD Hot water dipping

I Inhibition

i.e. Illud est

IC Inhibition concentration

IHS Institute of Horticultural Sciences

Fe Iron

kg Kilogram

KPK Khyber Pakhtunkhaw

L Liter

LC Liquid chromatography

LSD Least significant difference

M Molarity

m/v Mass over volume

MeJA Methyl jasoimnate

xxiv

Mg Magnesium

mg Milligram

min Minute

µL Microliter (s)

ml Milliliter

mm Millimeter

mM Millimolar

Mt. Metric ton

N Normality

Na2CO3 Sodium carbonate

NaCl Sodium chloride

NaHCO3 Sodium bicarbonate

NaOH Sodium hydroxide

nm Nano-meter

ns Non-significant

P Probability

PARS Post Graduate Agricultural Research Station

PE Pectin esterase

PG Polygalacturonase

PL Pectate lyases

ppm Parts per million

K Potassium

% Percent

± Plus minus

L-1 Per liter

R.H Relative humidity

RCBD Randomized complete block design

RCS Removal of central strands

ReID Refractive index detector

S.E Standard error

SA Salicylic acid

SBI Sindh Board of Investment

SL Soluble liquid

SSC Soluble solids concentrate

STT Shortening of terminal tips

TA Total titratable acidity

TFC Total tannin content

TGL Total glycoside limonin contents

TL Total limonin contents

TP Total pectin

TPC Total phenolic contents

TS Tree storage

TSS Total soluble solids

v/v Volume/volume

$ United States Dollar

viz. Videlicet

vs. Versus

1

Abstract

Grapefruit is an important fruit crop in the world as well as in Pakistan. This study was

carried out to investigate the effect of different harvesting dates, storage temperatures,

and pre-storage treatments of hot water, wax coating, pre-harvest spray of SA and Me JA

on the shelf life and quality of Ray Ruby and Shamber grapefruit. The fruits harvested in

month of December showed higher biochemical constituents than the fruits harvested

during September, October, November and January. The fruits stored at 8ºC and analysed

after 90 days storage showed minimum chilling injuries (3.55 and 3.22%) than the fruits

stored at 6ºC (11.44 and 10.22%) in Ray Ruby and Shamber respectively. The fruits

stored at 8ºC showed higher levels of TSS (6.67 and 6.97 ºBrix), ascorbic acids (38.87

and 39.21 mg/100g), total sugars (6.93 and 7.54 %), reducing sugars (4.33 and 4.93 %),

non-reducing sugars (1.85 and1.08%), total phenolic compounds (135.35 and 141.56 mg

GAE/100g), total antioxidants (57.56 and 61.97%), total cartotenoids (15.20 and13.81

mg/100g), total flavonoids contents (43.24 and 47.28 mgCEQ/100g ) and total limonin

contents (10.18 and 12.84 µg/mL) 90 days after storage in Ray Ruby and Shamber fruits,

respectively. Sweetness, sourness and general acceptances measured by sensory

evaluation showed that the fruits stored at 8ºC were preferred by the panellist than the

fruits stored at 6ºC as well as to those kept intact on the trees. Hot water treatment for 3

min + TBZ for 5 min showed higher TSS (6.82 and 6.98 ºBrix), ascorbic acids (34.43 and

43.50 mg/100g), total sugars (5.06 and 6.44%), reducing sugars (4.62 and 4.44%), non-

reducing sugars (2.02 and 1.99%), TSS/acidity ratios (5.57 and 4.77), maximum

organoleptic scores and higher phytonutrients such as total phenolic compounds (145.80

and149.90 mgGAE/100g), total antioxidants (57.25 and 60.44 %), total carotenoids

(14.49 and 16.36 mg/100g), total flavonoids contents (49.03 and 51.98 mgCEQ/100g) and

total limonin contents (11.97 and 10.99 µg/mL) with lower chilling injuries (0.66 and

0.44%) and fruit rots (4.44 and 3.88%) than untreated fruits in Ray Ruby and Shamber,

respectively. Chitosan application @ 140 mg per -1 fruit maintained highest fruit quality

parameters such as TSS values (6.93 and 7.21ºBrix), ascorbic acids (36.30 and 38.38

mg/100g), total sugars (6.24 and 6.67 %), reducing sugars (4.47, 4.71%), non-reducing

sugars (1.76, 1.96%), TSS/acidity ratios (5.25 and 6.00) after 90 days storage in fruits of

both cultivars. Maximum organoleptic scores, total phenolic compound (172.32 and

176.43 mgGAE/100g), total antioxidants (72.09 and 75.96 %), total carotenoids (17.09

and 18.98 mg/100g), total flavonoids contents (52.27 and 59.50 mgCEQ/100g ) and total

2

limonin contents (15.08 and 12.87 µg/mL) with minimum chilling injuries (1.58 and

1.33%) and fruit rots (0.66 and 0.33%) were also measured in same fruits. Pre-harvest

sprays of SA@ 12mM and MeJA @ 5 mM showed higher biochemical parameters such

as TSS (5.92 and 5.83, 6.17 and 6.09ºBrix), ascorbic acids (35.86 and 35.86, 39.17 and

39.17 mg/100g), total sugars (5.88 and 5.77, 6.31 and 6.18 %), reducing sugars (3.74 and

3.64% ,4.05 and 3.96%) and non-reducing sugars (2.14 and 2.14, 2.26 and 2.12%),

TSS/acidity ratio values (4.29 and 4.67, 5.82 and 5.38 ) in fruits of Ray Ruby and

Shamber respectively after 90 days storage. Maximum organoleptic scores for overall

acceptance (7.33, 7.22 and 7.66,7.44) and higher total phenolic compounds (166.29 and

165.76,170.48 and 167.28 mgGAE/100g), total antioxidants (72.63 and 71.37, 75.34 and

74.21%), Total carotenoids (16.40 and 16.32,18.09 and 18.03 mg/100g), total flavonoids

contents (55.74 and 53.43,58.30 and 56.04 mgCEQ/100g) and total limonin contents

(11.95 and 12.04, 10.66, 10.78 µg/mL) with minimum chilling injuries (1.57 and 1.42 %,

0.0 and 0.0%) and fruit rots (4.23 and 3.90%, 0 and 0 %) were also recorded in same

fruits. On the basis of the result of this study, the Ist December was observed as an

optimum time for harvesting of grapefruit varities Ray Ruby and Shamber. Pre-harvest

sprays of SA @ 12mM and MeJA @ 5Mm, pre- storage hot water treatment (53°C) for 3

mins + TBZ for 5 mints and Chitosan @ 140 mg per-1 fruit and storage temperature of

8°C was found the best for maintaining phytonutrient quality of grapefruit cultivars Ray

Ruby and Shamber for 90 days storage.

3

Chapter-1

INTRODUCTION

Citrus fruits are grown in more than 64 countries of the world (Chaudhry et al.,

2004) with a total production among the fruit crops of more than 105.4 million tonnes

annually (PHDEB, 2006). Citrus ranks first with respect to area and production in

Pakistan (Anonymous, 2013). Pakistan stands at 12th position among the citrus producing

counties of the world with a total area of 199,000 acres and total annual production of

2.36 million tonnes (FAO, 2013). Citrus fruit can be divided into 4 or 5 main groups such

as mandarin, sweet orange, pummelo, Grapefruit and lemon limes species. Grapefruit is

ancestor of pummelo and was separated from pummelo in 1830 (Webber, 1943). Name is

due to bearing habit just like a cluster of grapes. The peel glands contain the essential oils

that give the fruit typical fragrance. Juice contains ascorbic acid, soluble sugars, fiber,

pectin, organic acids, antioxidants and phenolic compounds.

These phytochemicals in grapefruit are considered very important for human

body due to their medicinal properties (Patil et al., 2004). Therefore it is important that

Grapefruit should be harvested and consumed when it has maximum quantity of these

chemicals. A little information is available about the effects of early and delayed

harvesting dates on these compounds.

Postharvest losses in the developed countries are 10-15% while in developing

countries these are 20-40%, depending upon the commodity (Kader, 1992). These losses

result from lack of appropriate pre and post-harvest traditionally harvesting factors,

insufficient packing houses, management like measures limited cold chain facilities and

slow marketing system, environmental stress also affect the grapefruit quality and cause

heavy losses. Proper storage conditions are therefore prevailing for extending the

consumption period of fruits and transportation for long distance. Grapefruit can be

stored in cold storage but discoloration, internal breakdown and decay are the serious

problems of storage. Therefore it is also important to establish techniques or to adopt

some measures that can reduce these losses.

4

Grapefruits of Pakistan are often of poor quality because growers start to harvest

the fruits in early months (July and August) at immature fruit stage. At this stage,

phytochemicals are not developed and these immature fruit are also sensitive to

physiological disorders. worldwide efforts have been made to control these problems and

to maintain optimum quality, freshness and minimize the losses during storage (Krochta,

1997; Hagenmaier, 2002; Bajwa and Anjum, 2007) by using low temperature storage,

polyethylene packaging and emulsion applications as wax coatings (Perez and Del-Rio,

2003; Thakur et al., 2002). The wax emulsion application is employed to control the

weight loss (Kaushal and Thakur, 1996; Alam and Paul, 2001) to fruit shrinkage and

approve appearance (Martinez-Javega et al., 1989). Performance of various wax micro

emulsions as fruit coatings depends on the quality of coating emulsion and presence of

ingredients present in it (Hagenmaier, 1998). Materials used in different types of coating

emulsions include lipids, polysaccharides and proteins are good film-forming materials

but they do not control the weight loss because they are not moisture barrier. Pre storage

techniques such as application of salicylic acid and methyl Jasomonate (MeJA),

fungicide, hot water dipping (HWD), wax application and postharvest technologies

including modified and controlled atmosphere (MA and CA) storage, intermittent

warming (IW) and temperature conditioning (TC) treatments are helpful to prolong the

high quality storage life of Grapefruit.

5

Keeping in views pre harvest and postharvest problems, the grapefruit has to face,

the present studies were planned with the following objectives.

1. To investigate the optimum harvesting date (harvest maturity) regarding their

phytochemicals.

2. To standardize the best storage temperature to maintain the phytochemicals.

3. To increase shelf life and improves quality of grapefruit during storage.

6

Chapter-2

REVIEW OF LITERATURE

2.1 History and origin of grapefruit

The grapefruit appears to have arisen from the pomelo, is through to have

originated as a mutation of the pomelo (Cirus grandis [L.] Osbeck) in the West Indines.

The grapefruit was first time documented in 1750 by Griffith Hughes. The grapefruit was

first described in 1750 by Griffith Hughes who called it the forbidden fruit of Barbados

(Morton, 1981). Its bearing habit is similar to grape because the fruits were born in a

cluster like grapes. Botanically, the grapefruit was not distinguished from the pommelo

until 1830 then it was given the name of Ctrus paradesi. It was introduced in Pakistan in

1940.

2.2 Overview of grapefruit

Citrus belongs to different groups and species and grapefruit is excellent specie

with their board nutritional spectrum. The grapefruit hesperidium is globosely elongated

and 4-30 centimeters long. The rind is leathery and attained segments which are filled

with pulp vesicles. Grapefruit plants are medium trees or large shrubs. The flowers are

solitary or in small corymbs. Each flower is 2 to 4 centimeters, with five white petals and

numerous stamens; they are often very strongly scented.

2.3 Grapefruit cultivars

Grapefruit have different cultivars according to their colour and most popular

cultivars are white, red and pink referring to the inside pulp color of the fruit. Grapefruit

cultivars have multi patches on fruit surface that is attractive for consumer.

2.4 Nutritional Profile and health benefits of grapefruit

Grapefruit is an excellent source of many phytochemicals and nutrients for human

diet. Grapefruit is a good source of antioxidants, vitamin C (Grang et al., 1998; Fellers et

al., 1990), pectin fiber (Cerda et al., 1988) and red hues, higher amount of antioxidant,

and lower levels of cholesterol (Grang et al., 1998; Lee, 2000; Platt, 2000). Grapefruit

due to its low glycemic index is able to help the body's metabolism and burn the fat

(WMUR, 2003). They are not only rich in calories but also contain adequate quantities of

other essential nutrients such as mineral protein and vitamins (Okwi and Emenike, 2006).

Grapefruits are good examples of healthy foods as they contain little fat and more

phytochemicals (Akobundu, 1999). They provide dietary fibers which maintain body

7

metabolism and waste elimination during bile acids and sterol fats (Akobundu, 1999).

The carbohydrate contents of grapefruit mainly comprise of dietary fibers, sucrose,

glucose and fructose. Frequent use of grapefruit juice prevents against the kidney stones,

gout arthritis and scurvy diseases.

2.5 Phytochemicals in grapefruit

The chemical compounds available in plants are called phytochemicals. There are

about 40 limonoids, 400 flavonoids and pectin in grapefruit (Craig, 2002). These

compounds occur in high concentrations and provide bitter taste in grapefruit and have a

ability to inhibit tumor formation by stimulating the enzyme glutathione S-transferase

(GST) (Craig, 2002). Consuming a diet rich in fruits and vegetables provides natural

antioxidants such as vitamins A, C and E, and natural bioactive substances

(phytochemicals) (Craig, 1997). Grapefruit also have a low ratio of sodium to potassium

and these are low in fat and dietary energy. Some major non-nutritive phytochemical

compounds found in grapefruit are flavonoids, glucarates, coumarins, monoterpenes,

triterpenes and phenolic acids (Baghurst, 2003). Humans require a diet containing

relatively small amounts of vitamins for normal metabolism and growth. Plants are a

major source of these essential vitamins with the exception of vitamin B12. It is

synthesized only by microorganisms while, vitamin D is obtained from sun exposure

(Kays and Paull, 2004).

2.6 World grapefruit industry

The global production and fresh consumption of grape are 7 million tons and 4.2

million tons respectively. The bulk of global production of citrus is dominated by oranges

followed by lemons and grapefruit (FAO, 2012). United States of America is still the

biggest producer of grapefruit in world. Florida is the number one grapefruit producer

which produces 50% of the total production while other producing countries are China,

South Africa, Mexico, India, Israel, Cuba and Argentina (USD, 2009).

2.7 Harvesting of grapefruit

There are different harvest maturity indices those are mostly used to harvest the

fruits. Harvesting of fruits at the proper stage of maturity is very important. Early

harvesting and delayed harvesting both effects the yield and quality of fruits therefore,

recommended maturity indices are important as they provide appropriate information for

the growers to decide the harvest maturity stage. Grapefruits should be harvested when

they are fully ripe because they are non-climacteric fruits. Quality of fruits cannot be

improved after harvest because the quality related parameters are developed in fruit when

8

they are attached with tree. The maturity indices that can be used for the harvesting of the

grapefruits are external appearance and juice quality (Popenoe and Drew, 1957; Ketsa et

al., 1999). It is also recommended grapefruit can be harvest after 150 days of fruit set

when they are physiologically matured (Singh, 1993; Lijuan and Zha, 2014). However,

variation resulting from varietal differences, growing regions, climate conditions and

methods used to determine growth rate, restrict the usefulness and wide application of this

indices.

2.8 Developmental structural and compositional changes in grapefruit on tree

The growth and development of a grapefruit takes 6-10 months or more to become

a fruit ready to harvest, depending upon the type and particular cultivar of fruit (Soule and

Grierson, 1986). Grapefruit are morphologically composed of two major regions, the first

is the pericarp which is known as the rind or peel and the second region is the endocarp.

The grapefruit can be further separated distinctly as the external coloured portion (the

epicarp or the flavedo) and the internal white layer of the peel (the mesocarp or albedo)

(Goldschmidt, 1988). The flavedo consist of epidermis, hypodermis and outer mesocarp.

The epidermis is composed of an epicuticular wax layer in platelets cell and mixture of

cutin wax and cell wall material. The flavedo also contains pigments in chloroplasts or

chromoplasts (Albrigo and Carter, 1977; Soule and Grierson, 1986; Baldwin, 1993;

Izquierdo and Sendra, 2003; Lijuan and Zha, 2014). The endocarp portion of grapefruit is

the most complex tissue and this edible portion is called the pulp which is composed of

the ovarian locules and segments that are enclosed in a locular membrane and are filled

with juice in sacs (Baldwin, 1993; Goldschmidt, 1988). Juice sacs appear at first as dome

shaped protrusions from the locular membrane into the locules. These tissues are initiated

at about full bloom. The domes develop into juice sacs through apical meristem activity.

Juice sacs are elongated in the mature fruit and are mostly spindle (elliptical) shaped

multicellular structures (Goldschmidt, 1988). Vascular bundles form a loose network

around the locules. Juice sac cells are highly vacuolated and the narrow cytoplasm

contains lipid droplets in plastids, leucoplasts and chromoplasts. Juice within the vacuole

of these cells is rich in organic acids and other soluble compounds such as amino acids

and salts. Calcium oxalate, hesperidine and naringin crystals can also be found in the rind

and juice sacs of grapefruit fruits (Shomer, 1975; Baldwin, 1993; Lijuan and Zha, 2014).

9

(A) (B)

Figure 2.1: A: Schematic drawing of a mature grapefruit emphasizing the vascular

arrangement (Goldschmidt, 1988). B: Diagrammatic equatorial cross-

section through a citrus fruit (Mc-Cready, 1977; Baldwin, 1993).

2.9 Quality changes during different harvesting dates of citrus fruits

The quality of citrus fruit gradually degrades after harvest in terms of both

external and internal attributes so choosing appropriate storage conditions is extremely

important to retain optimal quality. Physical and physiological changes during storage of

the fruit can be used as quality indices. Reuther and Rios-Castano (1969) reported that

delayed harvest in grapefruit minimized the juice contents and its acidity; it may decline

up to unacceptable level. Ke-Ling et al. (2005) demonstrated that ‘Navel’ orange fruit

harvested one month after harvest maturity showed marked increase in taste, TSS and

titratable acidity ratio while, the juice weight was reduced. Churchill et al. (1980)

reported that the peel firmness tensile as well as fruit compression of different cultivars

(Duncan, red blush and Thompson) are independent of harvesting date at temperature

45ºC.

In Pakistan there is standard method for maturity of grapefruit. Frist of all taking

representative sample of the fruit, extracting the juice in a standard and specified way and

then relating the juice volume to the original mass of the fruit it is possible to specify way

and then its maturity. In Pakistan the minimum values is 40 % the ratio of TSS and TA

can also be used with range of 5:1 to 7:1 (Thomposon, 2003). Jordan et al. (2001)

recognizing that sugar and acid have the opposite effects on flavor and the human taste

buds are more sensitive to acidity. Therefore they proposed subtracting TA from TSS

after multiplying TA by a constant that differs by fruit type. This measurement index,

give the name of Brim A, was found by authors to be more closely related to flavor then

TSS:TA. Other methods of assessing harvest maturity include peel colour, aroma, and

10

time after flowering. Grape fruit change from green to yellow as they mature and

aromatic compound increase.

Oliver et al. (2004) studied the effects of various harvesting dates and storing

temperatures (6-10oC) on qualitative characters of gape fruit. It was concluded that late

harvesting of grapefruit reduced titratable acidity (TA) and total soluble solids (TSS) at

(6-10oC) and showed no chilling injury after 30 days storage. They further reported that

late fruit harvesting reduces the bloom and fruit yield approximately 50% with low

quality of Valencia orange. Hilgemen et al. (1976) worked on the late harvesting stages of

valanica orange in case of their tree storage and they reported that late fruit harvesting

reduced the bloom in next year. It is also reported that valencia oranges can be stored

safely for period of six months at 6oC with relative humidity 85-90% (Pekmezic, 1995).

The experiment conducted by Pin (2004) on grapefruit cv. Star Ruby revealed that fruit

which were late harvested showed enhanced level of total soluble solid (°brix) and

decreased acidity. He further reported that ascorbic acid increased slowly until February

and then decreased.

2.10 Effects of harvesting maturity on Colour, total soluble solids content and

acidity

Generally, it is recommended that, a Brix/TA ratio ranging from 8-10 is taken as

a minimum value and a range from 10-16 is considered as being of acceptable quality of

grapefruit. If the fruit remain on tree, the brix increases while the acidity decreases

continuously until the fruit become overripe. Their value is based primarily on the

concentration of acid (citric acid) in the juice. Chlorophyll is found in chloroplasts and

the carotenoids are associated with chlorophyll and these are also found in chromoplasts.

Delayed harvesting reduced these compounds (Kays and Paull, 2004; Ghasemil et al.,

2013). De-greening of grapefruit peel is generally related to chlorophyll degradation and

consequential unmasking of carotenoids. These changes occur continuously under storage

temperature conditions and lower temperature, chlorophyll breakdown and fruit convert

their pigment compounds and fast ripening occurs (Wang, 1977; Gong and Mattheis,

2003; ).

2.11 Effects of storage temperature on the quality changes of citrus

Storage is used mostly to extend the shelf-life of products and maintain their

quality by adopting different techniques (Raghavan and Gariépy, 1985). A constant

temperature of 2-8oC is needed for storage of grapefruit for 8-12 weeks but it depends

upon the technology variation to be studied and its production starting (Murata, 1997;

11

Tahreen et al., 2012). Washington Navel and Egyptian orange fruits may be eaten safely

up to 4 and 3 months respectively, if properly cold stored (Isshak et al., 1978). Baldwin

et al. (1993) treated rough lemon cv. La Toma and Ruby red grapefruits with different

salts concentrations of CaCl2 and K and stored in cold storage to study the effect on

acidity. There was no-significant change in the acidity from start to the end of

experiment. However they found that Rough lemon cv. La Toma was more prone to the

postharvest temperature than the Ruby red with reference to acidity degeneration.

Marcilla et al. (2006) harvested full matured fruit and stored at different (5, 15, 20, 25oC).

They observed less increase in TSS and reported higher acidity in fruit those when they

were stored at lower temperature. It is also reported that fruit those are stored at different

temperatures significantly affect the quality parameter and those stored at lower

temperature showed poor quality (Murata, 1997; Isshak et al., 1978; Baldwin et al., 1993;

Tahreen et al., 2012).

2.12 Effects of storage on bioactive components.

Generally, ascorbic acid contents of fruits and vegetables tend to decline as the

temperature or its duration increases. However, limonoids and flavonoids contents seem

to increase with longer storage in grapefruit. Total phenolic compounds and antioxidants

decreases during storage due to internal enzymatic changes during storage. Harvest time

and other postharvest factors also influence the bioactive component levels during storage

(Adisa, 1986; Patil and Hallman, 2004).

2.13 Postharvest losses and physiological disorders

Recent advances in postharvest technology have been introduced, which helps in

minimizing losses and increasing fruit availability with acceptable quality. Availability of

large quantities of fruit over a short harvesting period poses problems for efficient

marketing and utilization, owing to perishable nature of the fruit (Baldwin et al., 1993).

Several techniques have been used to extend the postharvest quality of perishable fruits

and vegetables which include, low temperature, wax coating, polyethylene packaging and

modified atmospheric storage. Different physiological disorders like chilling injury, fruit

decay, postharvest peel pitting and changes in fruit texture can occurred during fruit in

which effects the quality of fruit (Perez et al., 2002; Xueping et al., 2013).

2.14 Effects of pre storage hot water treatments on quality of fruit during storage

Hot water treatment (HWT) is an effective heat transfer method to control the

decay in oranges (Fawcett, 1922). The additional benefit of HWT is that it can control the

postharvest diseases such as anthracnose and stem end rot (Couey, 1989; Garcia, 1995),

12

and these treatments are commonly used for disinfestations of flies (Nascimento et al.,

1992; Sharp et al., 1996). Hot water treatment is cheaper than any other heat-treatment

and recommended temperature ranges from 3-60°C. Jacobi et al. (1996) reported that

mango treated with conditioning at 40°C increased tolerance against the chilling injury.

Different scientists reported that fruits treated with HWT at 40ºC for 8-12 minutes

showed minimized heat injury and maintained internal and external quality and starchy

layer beneath the skin (Woolf et al., 1995). Hot water treatments were used for many

years as non-chemical method to control postharvest decay and diseases in various fruits

and vegetables (Lurie, 1998). Hot water treatment (2-3 min at 50-53°C) showed lowered

postharvest decay and CI in various citrus fruits and this method was not much expensive

(Rodov et al., 1995). Grapefruit immersed for 3 min at 53ºC showed 50% reduction in

decay during storage (Rodov et al., 1995). Ben-Yehoshua et al. (2000) reported that

grapefruit treated for 2 min at 51 and 54°C temperatures showed reduction in green mold

of lemon inoculated with the spores of Penicillium digitatum. Lanza et al. (2000) stated

that fruits treated with HWD + imazalil (1g/L) showed no decay than fruits untreated after

90 days storage. Ritenour et al. (2004) reported that fruits of grapefruit were dipped in

water at 56°C for 120 sec and they developed 8% SER in fruit as compared to fruits

treated with 33% SER dipped at 53°C in water. Fungicides used in heated solutions (50-

60°C) were also found more effective for controlling decay with thiabendazole (TBZ) and

imazalil (Wild, 1993; Schirra and Mulas, 1995).

Gohar et al. (2007) reported that fruits of sweet oranges were stored in cold

storage for 90 days after hot water treatment at 50°C for 15 min and were analyzed after

40 and 60 days of cold storage and it was observed that TSS and sugar contents increased

and weight reduced after 60 days of storage. It is also documented that various hot water

temperature treatments at different time intervals (2 to 3 min) reduces chilling injury and

control the fungal infection during cold storage (Rodriguez et al., 2005; Xueping et al.,

2013).

Ruby red grapefruits were stored at different temperatures (5, 20 and 25°C) for 60

days following dipping in hot water for 2 min at temperatures of 53 to 56°C. It showed

that 5 and 20°C temperatures reduced the chilling injury and decay as compared to 25°C

temperature storage. Slight change in TSS and sugar content of fruits were observed.

Similarly no changes were observed in total phenolic compounds and total antioxidants of

above temperature. Karthik et al. (2004) reported that it was concluded that hot water

treatments reduced chilling injury and decay of fruit during storage. It has been also

13

reported by Krista et al. (2005) that the quality of red-fleshed grapefruits stored for 90

days which were treated with hot water treatment at 40°C for 120 minute showed lower

titratable acidity and better flavour ratings than fruit treated at 52°C for 20 minutes.

2.15. Physiological disorders during storage

2.15.1 Introduction

Physiological disorders significantly influence the quality of citrus fruits during

storage and marketing periods. Pre-harvest and postharvest factors affect the incidence of

these fruit disorders in storage (Grierson, 1986; Murata, 1997). Pre-harvest factors are

boron & copper deficiency, sunburn, wind scar and freezing. Postharvest factors those

can induce physiological disorders during storage are temperature, humidity, atmospheric

gas composition, mechanical stress and aging. Physiological disorders are rind staining,

puffiness, granulation, oleocellosis, stem end rind breakdown, stylar end breakdown,

watery breakdown, chilling injury and freezing injury (Murata, 1997). Mechanical

damage also frequently occurs during the postharvest handling of fruit and is considered

as a type of stress. This stress results in physiological and morphological changes in

ethylene production rates and respiration of bruising and cell rupture and ion leakage

(Monselise, 1979). Chilling injury is the most serious problem for citrus fruit during cold

storage.

2.15.2 Chilling Injury (CI) and its causes

Chilling injury is a serious problem which directly affects the marketable values

of fruits. Different factors are mostly responsible for the development of disorders and

there are some techniques those can be used to minimize the losses due to these

physiological disorders. It is well known that weak fruits due to imbalance nutrition,

improper harvesting, improper handling practices and storage at undesirable temperatures

are mostly responsible for these physiological disorders (Grierson, 1986). Chilling injury

occurs when fruit hold below a critical threshold temperature but above their freezing

point (Kader, 2002). There is evidence that grapefruit showed CI when stored at

temperatures of 10-12°C (Chace et al., 1966). It is also very important to mention here

that fruit those were harvested in early and late season showed more susceptibility to CI

than the fruits those were harvested in mid-season (Grierson and Hatton, 1977).

Previously it was also reported that chilling injury can be reduced in many horticultural

commodities by managing the temperatures (Wang et al., 1993).

Chilling injury is a physiological disorder that can reduce the quality and value of

plants products, particularly tropical and subtropical plant species, as consequence of

14

their exposure to low but non-freezing temperatures (Parkin et al., 1989; Marangoni et

al., 1996). This defect is exhibited at temperatures above 0 to 8°C for subtropical plant

species such as citrus, avocado and pineapple and 12°C for tropical fruits such as banana

(Lyons, 1973; Sevillano et al., 2009). A better understanding of the physiological and

biochemical causes of injury and mechanisms of resistance is necessary to design more

effective control strategies and maximize shelf-life of the plant commodities and to

develop more resistant cultivars through plant breeding (Markhart, 1989; Parkin et al.,

1989).

Chilling injury is not simple disorder because the mechanisms involved in this

disorder differ in different tissues. There are several intrinsic qualities of the tissue (e.g.

species, cultivar, type of plant organ, developmental stage, and growing conditions) and

extrinsic qualities of the environment such as time and temperature interaction, relative

humidity, composition of the atmosphere and postharvest treatments that affect the

significance of CI (Lyons, 1973; Sevillano et al., 2009).

Several hypotheses have been proposed to clarify the mechanisms of CI (Serrano

et al., 1996). However, the exact mechanisms of this disorder and its effects are not

completely understood (Sevillano et al., 2009). For several years, CI was direct

consequence of the transition of lipids in cell membranes from a liquid to a gel state,

occurring at a lower temperature that led to a complete loss of permeability control in

fruit. He further reported that the phase transition temperature of pure lipids or lipid

mixtures is determined to a large extent by the fatty acid composition on the glycerol. The

greater the unsaturation of the fatty acids, the lower the phase transition temperature.

Therefore, membranes that contain high amount of unsaturated fatty acids showed

tolerate at lower storage temperatures than membranes with more saturated fatty acids

(Markhart, 1989). However, this suggestion is now regarded as an over simplification

(Marangoni et al., 1996).

2.15.3 Post-harvest treatments for reducing CI symptoms during storage

Scientists used different techniques to alleviate the CI in different fruits and

vegetables during storage. Hatton (1990) described that temperature management, which

included threshold temperatures control the CI symptoms. Fruits exposed at high

temperatures showed the potential risk of injury symptoms on fruit surface which can be

external (pitting, peel scalding, etc.) or internal i.e., discoloration, softening, off-flavors,

tissue disintegration (Lurie, 1998). Miller et al. (1988) reported that fruits were dipped at

43- 50°C for 3-4 minutes in HW and were stored for 3 weeks. It was observed that

15

symptoms of peel discoloration and decay were significantly reduced. Schirra et al.

(1997) treated the grapefruit with hot water and observed that fruits treated with HW

(53°C for 3 min) showed lower Cl (40%) during storage. Fruits harvested between

November and January were more susceptible to CI than fruit harvested in February.

Immature fruit attained more Cl than untreated fruit (Schirra et al., 1998). It is also

reported that fruit treated with the benomyl (500 mg/L) and TBZ (1000 mg/L) for 2 min

at ambient temperature or 53°C showed lowered CI after 15 weeks of storage at 1°C

(Wild and Glasson, 1998).

2.16 Respiration and Juice quality changes during storage

Respiration changes cause the breakdown of organic material into simple products

providing energy required for various metabolic processes and results in the loss of food

reserves during storage (Kader, 2002). During storage, increased respiration rate enhances

metabolic processes in fruits which causes senescence. Storage temperature affects the

respiration rate of fruits and vegetable. Schirra and D’hallewin (1997) reported that after

33 day in storage, respiration rate was higher in ‘Fortune’ mandarins dipped in 56 or

58°C water. They further reported that quality changes regarding the effects of ethylene

rate production was also higher in fruit those were treated at 58°C and these fruits showed

good total soluble solids and titratable acidity (TA). Schirra and D’hallewin (1997)

conducted an experiment on oranges by dipping these fruits at 53°C for 3 min and

observed significant changes in respiration and noted higher TSS and TA during storage

after 60 days. Fruits treated with hot water brushing at 56°C for 20 sec did not affect the

TA and juice TSS in ‘Minneola’ tangerines, ‘Shamouti’ oranges and ‘Star ruby’ red

grapefruits during storage (Porat et al., 1999).

2.17 Textural properties and fruit firmness

Fruits firmness depends mainly on turgidity of cell and weight loss (Rodov et al.,

1995). Fruits those were treated with hot water treatments caused the redistribution of

natural epicuticular wax on the fruit surface and covered those fruit with many

microscopic cuticular cracks than the fruits which were untreated (Rodov et al., 1995).

Hot water treatments inhibited the enzymatic action involved in softening and enhanced

cell wall strengthening processes like lignification. Fruits treated with hot water for 2 min

at 52°C maintained fruit firmness by inhibiting fruit softening process (Rodov et al.,

2000).

16

2.18 Wax coating

Wax coating are commercially used to reduce the moisture loss of fruits and

improves fruit quality during storage (Dhillon and Randhawa, 1985). Different types of

wax coating such as wax emulsion, hydrazide, maleic and polysaccharide-based coating

also delays ripening process during storage.

2.19 Fruit coatings and wax applications

Films and coatings received much attention in recent years because they

improve quality and extend shelf-life by providing a barrier to mass transfer, carry food

ingredients and improve mechanical integrity or handling characteristics of food

(Krochta, 1997). Waxing treatments is a normal practice in today’s packing houses,

aimed to replace natural waxes on fruit surface. Wax coating application serves to reduce

fruit shrinkage and improve fruit appearance during storage (Martinez et al., 1989). Types

of materials used in coating emulsions include lipids, polysaccharides, resins and

proteins. Proteins and polysaccharides are good film-forming materials in fruit but these

films do not show any function as moisture barriers. Lipids coating on fruit surface show

better moisture barrier but present low mechanical integrity (Krochta, 1997; Chienl et al.,

2013). To maximize the advantages, many formulations including composite coatings of

both groups has been documented (Krochta, 1997; Debeaufort et al., 1998). These

composite coatings contain chitosan, cellulose derivatives, and acid sucrose fatty ester

emulsifiers (Baldwin et al., 1999). Fruit those were treated with wax showed more quality

related parameters as compared to fruit those were untreated (Nisperos-Carriedo et al.,

1990; Hagenmaier, 2000; Hagenmaier, 2002). However, lack of knowledge about

composition of many commercially available coating makes it difficult to predict their

performance on fruit quality during storage (Perez and Rio, 2003).

2.20 Chitosan wax coating

Liu et al. (2007) studied the effect of chitostan on grey mould and blue mould

caused by Penicillium expansum and Botrytis cinerea in tomato fruit stored at 2 and

25°C. They reported that fruit treated with chitosan showed maximum control against

both the tomato diseases during fruits storage at 2 and 25°C. Chitosan treatment induced a

significant increase in the performance of peroxidase (POD) and polyphenoloxidas which

improved the contents of phenolic compounds in tomato fruits. Chitosan directly affected

the microbial activity and it was noted that chitosan treatment developed an enzyme

defense system (Bautista et al., 2006). Chitosan also delay the natural ethylene production

17

rate in fruit; reduce peel pigmentation without affecting the interior quality of fruit

(Fernando et al. (2008). Fruits treated with chitosan showed reduced titratable acidity,

ascorbic acid contents and total soluble solids and significantly less diseases with

extended shelf life (Zeng et al., 2008). It was reported that chitosan coating (1.5%) on

strawberries fruits delayed changes related to weight loss, firmness and external colour

(Pilar et al., 2008). Faten et al. (2010) worked on the effect of different chitosan

application and found that chitosan treatment with 5 g/L and 8 g/L reduced the disease

and controlled the fruit rot% significantly.

2.21 Physicochemical changes during storage of grapefruit

There is an inverse relationship between the fruit growth rate, its quality

and extended storage on the tree and postharvest life. Changes in sugars, acidity and

total soluble solids of the juice depend on the conditions in which fruit are stored. Fruits

stored at higher ambient temperatures with lower relative humidity showed rapid water

loss from the surface. Water loss causes increase in levels of TSS and reduce the acidity.

It is previously reported that fruits those were stored at higher relative humidity showed

higher acidity declines in various citrus fruits during ambient storage (Chattopadhyay et

al., 1992). Angadi and Krishmanath (1992) reported that during storage total soluble

solids contents remained unchanged while total titratable acidity content decreased. They

further reported that changes in physicochemical parameters are dependent on harvesting

periods which influence the weight loss, pH, acidity, sugars, ascorbic acid and titratable

acidity. Nagar (1993) stated that delayed harvesting beyond the second week of January

increased weight loss but reducing sugars and total soluble solids gradually increased

irrespective of the harvesting period and storage (Nagar, 1991).

Ascorbic acid is a water-soluble vitamin and it rapidly oxidizes by the action of

light, heat and by the action of ascorbic acid oxidase. Prolonged storage of fruits results in

losses of vitamin-C but these changes under cold conditions are less as compared to room

temperature (Pal and Sanjay, 1997). Fruits treated with coatings and stored at container

showed significantly higher ascorbic acid as compared to uncoated and stored under

ambient conditions (Thakur, 2002; Flores et al., 2014). The decline in ascorbic acid

content depends upon the harvesting period and delayed harvested fruits showed

reduction in the ascorbic acid content from 42.00 to 38.8 mg/mL juice (Nagar, 1993).

Similar results have been also reported by Singh (1993) who reported that during storage

of citrus fruits under refrigerated and ambient conditions, ascorbic acid contents

decreased rapidly at higher temperature.

18

2.22 Respiration changes during storage

After harvesting, fruits continue their respiration and the rate of respiration

directly affects the shelf life and quality. A decrease in respiration rate during storage is

usually beneficial in maintaining the quality of the product (Calegario et al., 2003).

However, stresses such as pathogen infection, chilling injury, mechanical damage and

treatment with external ethylene effect the respiration (Baldwin, 1993). Citrus fruits have

a relatively low respiration rate and also produce only small amounts of ethylene, so fruits

can be stored for longer period (Porat et al., 1999; Artes-Hernandez et al., 2007).

However, ripening-related changes associated with pigment changes and chlorophyll

degradation in certain non-climacteric fruits such as citrus is accelerated by the

application of external ethylene and coating (Monselise, 1979; Flores et al., 2014).

2.23 Antioxidant activity and flavonoids changes

Antioxidants and flavonoids are secondary metabolites that are found naturally in

fruits and vegetables. Antioxidants can be defined as anything that prevents or inhibits the

oxidation of a substrate (Krishnaiah et al., 2007; Flores et al., 2014). Fruits undergo

aerobic cells metabolism and produce free radicals. Rate of oxygen consumption inherent

in cell cause the growth for the generation of a series of free radicals cause oxidative

stress. This group of radicals comprising superoxide, lipids peroxides and hydroxyl may

interact with biological systems and toxic effects are produced. These species interact

with other life essential molecule and cause oxidative reactions which changes alterations

of protein (Saez et al., 1994; Lijuan and Zha, 2014). Citrus flavonoids and phenolic

compounds have been reported to possess ability to capture electrons and scavenge the

radicals. Flavonoids of citrus form dislocation of tautomeric, which prevents the

propagating chain reactions of these oxygen free radicals. Robert (1998) reported that free

radicals are responsible for the cell oxidation process such as superoxide anion (O2),

singlet oxygen (1O2), hydroxyl radical (OH) superoxide anion (O2), and peroxyl radical

R-O-O.

2.24 Role of Salicylic (SA) and Methyl Jasominate (Me JA)

Pre-harvest spray of different chemicals reduces the Cl symptoms and enhances

antioxidants in fruits. There are some references in the literature those indicate that

different groups of growth regulators such as salicylic acid (SA) , methyl Jasmonate (Me

JA), abscisic acid (ABA), and jasmonic acid (JA) enhance the mechanism that protects

fruits from CI (González et al., 2000). SA is signaling molecule, mediates defense for

many pathogens and also play an essential role in thermogenesis during storage. JA and

19

Me JA are called growth regulators. Wound of these compounds release an 18 systemin,

amino acid polypeptide that activates cell membrane lipase enzyme. These compounds

are volatile in nature as they provide quick signals to neighboring cells and promote them

to produce some chemicals before any injury occurred. It is reported that papaya and

strawberries were treated with MeJA (5-10 mM) and stored in MA packaging at 10ºC and

found inhibition in fungal decay and in CI (González-Aguilar et al., 2003). Wang and

Buta (1994) reported that Cl symptoms were reduced in squash fruits those were treated

with MeJA in cold storage. The treatment of MeJA also found effective to reduce the CI

in mangoes (González-Aguilar et al., 2000), in grapefruit, bell pepper and avocado

(Meyer et al., 1992). Jasmonates are also play significant role in numerous physiological

fruit processes (Hartmond, 2000), specifically in stress, senescence and leaf abscission

(Gross and Parthier, 1994). It is also well known that methyl jasmonate (MeJA) is a

natural compound of plants which play an important role in growth, development and

response to different stresses. Its pre or post-harvest treatment reduce the brown rot in

sweet cherry (Yao and Tan, 2005), suppress the gray mold in rose flowers (Darras et al.,

2005) and reduces the decay in papaya fruits (Gonzalez-Aguilar et al., 2003). It also

induces the promotion of senescence which can be characterized by the chlorophyll

degradation, inhibition of lycopene accumulation (Sanieswky and Czapsky, 1985).

Methyl jasmonate also plays an important role to improve the color by stimulating the

anthocyanin biosynthesis (Prez al et., 1997; Tahreen et al., 2012). It is also known that

salicylic acid plays an important role against fungi and diseases (Singh, 1978; Rainsford,

1984; Li et al., 1999; Flores et al., 2014). Treatment of salicylic acid suppress the

postharvest anthracnose diseases caused by Collectotrichum gloeosporioides in mango

fruit (Zainuri et al., 2001), Pear fruit (Cao et al., 2006) and reduce the fungal decay in

sweet cherry through defense resistance (Chan and Jiang, 2006). Zhang and Zheng (2004)

reported that MeJA treatments inhibit the fruit decay in strawberries. Moreover, the total

phenolic contents increased more rapidly and stayed at significantly higher levels in fruits

treated with MeJA than the fruits of control. Higher antioxidants activities were also

observed in the SA pre-harvest treated fruits when compare with the control (Renhua et

al., 2008; Lijuan and Zha, 2014). Hongjie et al. (2004) also studied the effect of foliar

application of SA and MeJA on sweet cherry. They found that SA @ 2mM and MeJA @

0.2mM showed best results to inhibit the spore germination on fruits.

20

The research findings described in the preceding lines throw light on the status

and challenges faced by grapefruit in Pakistan. It also suggested to make some plan to

combat these problems therefore the present studies were planned and executed.

20

Chapter-3

MATERIALS AND METHODS

Worldwide, grapefruit have different cultivars according to their colour and most popular

cultivars are white, red and pink referring to the inside pulp color of the fruit. Grapefruit

cultivars have multi patches on fruit surface that is attractive for consumer. In Pakistan,

grapefruit has two important cultivars such as Ray Ruby (Slide-1) and Shamber (Slide-2).

Slide-1: Ray Ruby Slide-2: Shamber

These research studies were conducted during 2010-2012. Materials and methods are

detailed as under, while specific information is given under separate experiments.

3.1 Experimental materials and site selection

The studied factors included harvesting dates and varieties. Thirty uniform and

healthy grapefruit trees grafted on lough lemon rootstock were selected at orange

Research Institute Sargodha (latitude 32o 03’ N and longitude 72o 40’ E) Punjab,

Pakistan. Fruits were randomly harvested from selected trees with fruit clipper and

brought to the Pomology Lab Institute of Horticultural Sciences, University of

Agriculture Faisalabad Pakistan. Some analytical work was conducted in the laboratories

of Post-harvest Research Centre, Ayub Agricultural Research Institute (AARI),

Faisalabad, Pakistan, Biological and Bioassay Laboratory of Chemistry and Biochemistry

21

Department, University of Agriculture Faisalabad, Pakistan and Department of Plant

Pathology, University of Agriculture, Faisalabad, Pakistan.

3.1.1 Experiment-1: Effects of different harvesting dates on the quality and the shelf

life of grapefruit.

Fruits were harvested at different dates viz. 1st September, 1st October, 1st

November, 1st December and 1st January during both years. Fruit were washed with tap

water and air dried. Ten fruits were taken as a treatment unit, replicated three times

(n=30) for each variety. These fruits were used for the determination of physical

characteristics, biochemical and phytochemical analysis detailed below.

3.1.1.1 Physical parameters

3.1.1.1.1 Fruit diameter (mm)

A diameter of 10 fruits was measured with help of digital caliper (Mitutoyo 500-

171-20, Japan) and their average was calculated.

3.1.1.1.2 Fruit weight (g)

Ten fruits were used to determine their weight by using a digital balance, (Model

was (PTL, RX 5000 and Japan) and their average was calculated.

3.1.1.1.3 Number of seeds per fruit

Seeds of ten fruits from each treatment unit were counted. Samples were used to

measure the number of mature and aborted seeds.

3.1.1.1.1.4 Peel weight (g)

Peel weight was calculated from 10 fruits of each treatment unit and then peel

weight for composite sample was calculated. The percentage was then calculated by

using following formula:

Fruit peel weight = Juice weight x 100

Fruit weight

3.1.1.1.1.5 Pulp weight (%)

Pulp weight from 10 fruit was determined and its average was calculated. Pulp

weight was calculated by the following formula:

Pulp weight = Pulp weight x 100

Fruit weight

22

3.1.1.1.1.6 Rag weight (%)

Rag weight from 10 fruit was determined and its average was calculated. Rag

weight was calculated by the following formula:

Rag weight = Rag weight x 100

Fruit weight

3.1.1.1.1.7 Juice weight (%)

Juice weight was determined by subtracting rind and rag weight from fruit weight

and expressed as percentage.

3.1.1.1.1.8 Number of oil glands (per 180 mm2)

Fruits were taken within a sector of 180 mm2 along the equator of the fruit.

Glands visible on the surface using a dissecting microscope, were counted the number of

glands with deeper-seated cavities, difficult to detect from surface examination, were

counted by dissection of the tissue along the flavedo/albedo boundary. The sum of these

two counts gave the total number of glands within the sector. For all fruit, number of

gland density was expressed as number of glands per 180 mm2. The total number of

glands per fruit was estimated using values of gland density and fruit surface area:

Total gland number = gland density x fruit surface area/180 mm2 (Turrell, 1946).

3.1.1.1.1.9 Number of segments

Numbers of segment form 10 fruits of each treatment unit were counted and then

average was calculated.

3.1.1.1.1.10 Fruit firmness (Nm²)

Fruit firmness was measured with the help of penetrometer and expressed

pressure necessary to force a plunger of specified size into the pulp of the fruit then

average reading was calculated in the fruit.

3.1.1.1.1.11 Pulp/peel ratio

Pulp and peel of 10 fruits were weighted individually and expressed as pulp/peel

ratio as following formula

Pulp/peel ratio = Pulp weight

Peel weigh

23

3.1.1.2 Biochemical analysis

3.1.1.2.1 Juice pH

Fruit juice pH was measured with a digital pH meter (HI 98107, Hanna, Mauritius

at 18 ºC ±2 ºC.

3.1.1.2.2 Total soluble solids (˚Brix)

Total soluble solids of juice were recorded by using digital hand refractometer

(Atago, RX 5000 and Japan).

3.1.1.2.3 Total titratable Acidity (%)

Total titratable acidity was determined by the method described by Hortwitz

(1960). Juice samples were titrated against 0.1N NaOH using two to three drops of

phenolphthalein as an indicator, and the results were expressed in percentage.

T.A. (%) = 0.1N NaOH used x 0.0064 x 100

Volume of sample used

3.1.1.2.4 TSS/acid ratio

TSS/acid ratio was calculated by dividing the percentage of total soluble solids

with the percentage of total titratable acidity.

3.1.1.2.5 Ascorbic acid (mg/100g)

Five mL of aliquot (containing 10 mL of juice and 90 mL of 0.4% oxalic acid

solution) was titrated against 2, 6-dichlorophenolindophenol dye solution (Ruck, 1961).

3.1.1.2.6 Sugars (total sugars, reducing and non-reducing sugars)

Sugars were estimated according to the method of Hortwitz (1960). Reducing

sugars were titrated against Fehling’s A and B solutions by using methylene blue as an

indicator until brick-red color appear as end point. For total sugars, juice samples were

first acid hydrolyzed and then titrated by the method described above.

3.1.1.3 Phytochemical parameters

3.1.1.3.1 Total phenolic contents (mg GAE/100 g)

Total phenolic contents (TPC) were calculated by using Folin-Ciocalteu reagent

method as reported by Ainsworth and Gillespie, (2007). The FC-reagent (10 mL) was

dissolved in distilled water to make the solution 100 mL. In each sample (100 mL), FC-

reagent (200 μL) was added and vortex thoroughly. The 700 mM Na2CO3 (800 μL) was

added into each sample and incubated at room temperature for 2 h. Sample (200 μL) was

24

transferred to a clear 96-well plate and absorbance of each well was measured at 765 nm.

Amount of TPC was calculated using a calibration curve for Gallic acid. The results were

expressed as Gallic acid equivalent.

3.1.1.3.2 Total antioxidants (% DPPH inhibition)

Total antioxidants activities of the grapefruitjuice was assessed by measuring their

scavenging abilities to 2, 2-diphenyl-1-picrylhydrazyl stable radicals as described by

Amira et al. (2012). The absorbance was read against a blank at 517 nm using micro-

plate ELISA reader (BioTek, USA). Inhibition of free radical by DPPH in percent (%)

was calculated by following formula:

I % = (Ablank -Asample /Ablank) × 100

Where Ablank is the absorbance of the control reaction mixture excluding fruit sample, and

Asample is the absorbance of the test compounds. IC50 values, which represented the

concentration of date fruit extracts that caused 50% neutralization of DPPH radicals,

were calculated from the plot of inhibition percentage against concentrations.

3.1.1.3.3 Total flavonoids contents (mg CEQ/100 g)

Flavonoids were determined by the method of Kim et al. (2003). Distilled water

(4 ml) was added to 1 ml of fruit juice. Then, 5% sodium nitrite solution (0.3 ml) was

added, followed by 10% aluminum chloride solution (0.3 ml). Test tubes were incubated

at ambient temperature for 5 min, and then 2 ml of 1M sodium hydroxide were added to

the mixture and then the volume of reaction mixture was made up to 10 ml with distilled

water. The mixture was thoroughly vortex and the absorbance of the pink colour

developed was determined at 510 nm. A calibration curve was prepared with catechin and

the results were expressed as mg catechin equivalents. All the measurements were taken

in triplicate and the mean values were calculated.

3.1.1.3.4 Limonin contents (µg/ mL)

Total Limonin and limonin glycoside contents were isolated and evaluated for

purity (Breksa et al., 2004) were used to prepare 500 µg/ mL stock solutions in

acetonitrile were stored at 20ºC. Juice samples were clarified by centrifugation (16000g,

5 min,10 C), and the supernatant was collected and filtered through filter paper

(Whatman #1, Whatman Inc., Clifton, NJ) for the estimation of limonin contents.

25

Using these values, the limonin equivalence (µg/mL) of the sample was calculated using

the equation.

3.1.1.3.5 Total pectin contents (mg/100 g)

Mature fruits of grapefruit were taken than they were stored at room temperature

(30°C) for 30 days before using in the experiment. Fruit peels were cut into a cube shape

approximately 4×4×4 mm3 and dried at 50°C in hot-air oven. Dried peel of grapefruit was

weighted (100 g) was extracted with water (2,000 mL × 2 times) at different pH levels of

(2, 3 and 4.5) at (80 and 100°C) for 3 hours. The extract was concentrated under reduced

pressure to the final volume of 200mL. It was further dialyzed (D9527, Sigma-Aldrich,

St. Louis, Missouri, USA) for 1 hour, repeated 8 times. Pectin was precipitated by

adjusting pH to 3.5 and adding double volume of 95% ethanol. After centrifugation at

3,500 rpm for 8 min and washing with 95% ethanol, pectin was collected and dried at

50°C. The peel was soaked in water for overnight and filtered before using for the

extraction. After precipitation, the extracted pectin was either directly collected by

filtration through cheese cloth or centrifugation and washing.

3.1.1.3.6 Total carotenoids contents (mg/100g)

Total carotenoids contents were estimated according to the method of

(Lichtenthaler and Buschmann 2001). Frozen grapefruit juice (5ml) was extracted with

1mL of pure acetone and then mixture was homogenized for 1 min and incubated at 4oC

in darkness until the cap turned white. The homogenate was centrifuged at 16,000×g for

15min and 200µL of supernatant from each tube were placed in 96-well plates. The

absorbance was read at 470 nm in a micro-plate reader (Power Wave HT, Bio. Tek). The

concentration of total carotenoids was calculated as follows:

TC (µg/mL) = (1000×A470)/214, and expressed as mg/100 g fresh weight.

(Additional experiment done and published in International Journal Biology

Biotechnology with authors and title. Ahmed, W., Ahmed

S., Malik, A. U and A

Rashid. 2013. Determination and Comparison of harvest by traditional and modern

methods on quality and storability of grapefruit. Int. J. Biol. Biotech. (4): 571-576.

26

3.2.1 Experimen-2a Effects of cold storage and tree storage relating to their quality

and shelf life of grapefruits. Ray Ruby

3.2.1.1 Fruit harvesting

Fruits were harvested in month of December and stored at 6-8˚C for 90 days and

other fruits remained attached on tree. After every 30 days fruit were removed from the

cold storage and harvested from the tree and analyzed.

3.2.1.2 Washing and cleaning the fruits

Harvest fruit were washed using sodium hypochloric solution 100 ppm in a plastic

tube to remove adhering extraneous matters on the fruit surface and sorting was carried

out for unsound/damaged fruits and then uniform colored grape fruits were separately.

3.2.1.3 Fungicides applications

Thiabendazole (TBZ) @1000 ppm was applied in the room temperature at 30°C

for 10 minutes.

3.2.1.3.4 Storage conditions

Harvested fruits were stored at two different temperatures i.e. 6 and 8°C at 85-

90% RH in cold chambers equipped with automatic relative humidity and temperature

control system. The grapefruit samples from each treatment were randomly taken after

every 30, 60, 90 days interval during the whole period of storage starting from fresh fruit

given below.

3.2.1.3.5. Treatment layout

Fruits were harvested on 1st December and stored at 6-8°C for 90 days and other

fruits remained attached on tree. After every 30 days fruits were removed from the cold

storage and harvested from the trees and analyzed.

0- days (fresh)

30- days after storage (DAS)



All the quality related parameters were calculated as mentioned in the section 3.1.1.

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3.2.1.3.5.1 Physiological disorders

3.2.1.3.5.1 Weight loss (%)

Ten fruits (n=10) were randomly selected from each treatment unit. These fruits

were weighted as fresh and at 30 days internal during the storage period and weight was

calculated using the following formula (Takur, 2002).

WL (%) = Original Fruit weight- final fruit weight after storage x 100

Average fruit weight

3.2.1.3.5.2 Chilling injury (%)

Chilling injury during the storage was calculated by using the following formula.

Chilling injury (%) = Number of affected fruits per treatment x 100

Total number of fruits per treatment

3.2.1.3.5.3 Fruit rot (%)

Fruit rot during the storage was estimated by using the following formula.

Fruit rot (%) Number of affected fruits per treatment x 100

Total number of fruits per treatment

3.2.1.3.5.4 CO2 and Ethylene production

Rates of CO2 and ethylene production were measured by the static system. Ten

fruits per replication were weighed and sealed together in a 3 L container for 2 h. Gas

samples of (2, 3, 4, 5) were withdrawn through a rubber septum using a syringe and the

percentage of carbon dioxide determined using a Gow-Mac gas chromatograph

(Series580, Bridgewater, N.J.) equipped with a thermal conductivity detector. The

respiration rate was calculated using the following formula:

Respiration rate (mL CO2·kg-1·h-1) = %CO2 volume (mL)

Sample weight (kg) X sealed time (h) X 100

Ethylene production was measured by injecting a 1 mL gas sample into a HP

5890 gas chromatograph (Hewlett Packard, Avondale, Pa.) equipped with a flame

ionization detector. The rate of ethylene production was calculated using the following

formula:

µL C2H4·kg-1·h-1 = ppm C2H4 X void volume (mL)

Sample weight (kg) X sealed time (h) X 100

28

Side-3 Fruit stored at 8°C after 90 days of storage for both cultivars (Ray Ruby and

Shamber)

Slide-4 Fruit stored at 6 °C after 90 days of storage for both cultivars (Ray Ruby

and Shamber)

29

3.2.1 Experimen-2b Effects of cold storage and tree storage relating to their quality

and shelf life of grapefruits cv. Shamber

Same procedure of layout and analysis were carried out as mentioned in

experiment 3.21a the section but shamber cultivor was used in this experiment.

3.3.1 Experiment-3a Comparison of hot water treatment and fungicide against

quality and the shelf life of grapefruits. Ray Ruby


Grape fruits (n =130) of uniform size and colour were harvested from 18 trees of

grapefruit and shifted to the Department of Post-harvest Centre, Ayub Agricultural

Research Institute, Faisalabad. They were stored at room temperature overnight and hot

water treatment was applied on the next day.

3.3.1.2 Washing and cleaning of fruits

The fruits were washed using 100 ppm sodium hypocloric solution in in a plastic

tube to remove adhering extraneous matters on the fruit surface and again uniform

colored and size were sorted out.

3.3.1.3 Hot water treatment procedure

Harvested fruits were dipped in water at 53°C for 3 and 4 minutes in a temperature

controlled water bath (Optima series immersion circulators, Boekel Scientific,

Feasterville, Pa.). Heating was accomplished using a large gas burner with the

temperature varying by +1°C during each treatment. Therefore the fruit were stored at

8°C and 90% RH. Ten fruits from each replicate were randomly selected and marked for

measuring the weight loss during storage. Initial analysis of peel color, total soluble

solids (TSS), titratable acidity (TA), and peel and percent juice weight were done Decay,

rotting fruit; chilling injury was evaluated at 30, 60 and 90 days storage (DAS)

3.3.1.4. Fungicide applications after HWT

Thiabendazole (TBZ) @ 1000 ppm and Imazalil @ 1000 ppm were applied with

time interval of 5 min according to the treatments and fruits were direded in the room

temperature at 38°C for 3 minutes.

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3.3.1.5. Storage conditions.

Fruit were stored at 8ºC as described in the section 3.1.1. Afterward the grape

fruits were stored at (8oC) 30, 60 and 90 days at 85-90% RH in cold chambers equipped

with automatic relative humidity and temperature control system

3.3.1.6. Experimental treatment layout

There were five post-dip treatments of grapefruit of both cultivators given below

T0 : (Sample water applied)

T1 : HWD (53oC- 3 mins) + TBZ (5min)

T2: HWD (53oC- 3 mins) + Imazalil (5min)

T3: HWD (53oC- 4 mins) + TBZ (5min)

T4: HWD (53oC- 4 mins) + Imazalil (5min)

All quality parameters of section 3.1.1 and 3.2.1 were measured. Some

physiology parameters such as fruit weight loss, fruit rot, gases, heat production were

also studied.

3.3.1 Experiment-3b Comparison of hot water treatment and fungicide against

quality and the shelf life of grapefruits cv. Shamber

Similar procedure and parameters analysis were carried out as mentioned in the

section 3.3.1a. But Shamber cultivar was use in this experiment.

31

Hot water treatments at 53°C Hot water treatments at 53°C

Hot water treatments after 90 days analysis Hot water treatments at 53 °C

Analysis after 90 storage of storage Analysis after 90 storage of storage

Slide: 5 Hot treatment of grape fruit and analyzed after 90 days of storage

32

3.4.1 Experiment-4a Effects of Wax Coating on the quality and the shelf life of

grapefruit of Ray Ruby.


One hundred and eight fruits of both varieties from 18 trees were harvested during

November from the orchard of Orange Research area and shifted to Department of post-

harvest center Ayub Agricultural Research Institute for the study.


Harvested fruits were washed in a plastic tub using sodium hypochloric solution

@ 100 ppm before storage.

3.4.1.3 Fungicides applications

After washing fruits were treated with Thiabendazole (TBZ) @ 1000 ppm for min

and then dried at room temperature of 38oC for 5 minutes.

3.4.1.4 Preparation of wax coating

Chitosan-oleic acid coating was prepared according to a method described by

Vargas et al. (2004) method. Chitosan (1-2%) was dispersed in an aqueous solution of

glacial acetic acid (1%, v/v) at 40°C. Tween 80 solution at 0.1% (v/v) was added to

improve wettability. After 8 h of stirring, oleic acid (1-4%) was added to the chitosan

solution.

3.4.1.5 Application of wax coating

The grape fruits were coated using a self- made coating apparatus. The speed of

the brush rollers was at 160 rpm and the coating solution was sprayed at 10 mL/min.

Each piece of fruit was weighed about 10 second before and again 10 second after

application, to determine the wet weight of the coating applied (Hagenmaier, 2002). The

mean wet weight of the coating was about 0.20 mg per fruit. These fruits were then dried

using an electric fan at room temperature (30±2°C) for 30 minute and placed in cold

storage.

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3.4.1.6 Treatments lay out

T0: Control (without wax applied)

T1: Chitosan 120mg-1 per fruit (5 min) dipping



All the quality parameters were estimated as mentioned in the section 3.3.1 and similar

procedure was adopted for their analysis.

3.4.1 Experiment-4b Effects of Wax Coating on the quality and the shelf life of

grapefruit of Shamber.

Same procedure and analysis of parameters were carried out as mentioned in the

section 3.4.1a. however, Shamber cultivar was used in this experiment.

3.5.1 Experiment-5a Effects of pre-harvest spray of salicylic (SA) and Methyl

Jasmonate (MeJA) on the chilling injury, decay and

phytochemicals during the storage in grapefruits. Ray Ruby

3.5.1.1 Preparation of salicylic acid solution

Salicylic acid (SA) solution was prepared by dissolving SA powdered in ethanol

solution than gently heat was applied so that its dissolved completely it was @ 6, 8 and

12 mM and then applied on trees of grapefruits foliar application before harvesting at 20

days intervals.

3.5.1.2 Preparation of methyl jasmonate solution

Different concentrations of MeJA (3, 4 and 5 mM) were used. MeJA solutions

were prepared by dissolving powder in ethanol solution and stirred. The solution of 3, 4

& 5 mM MeJA solution was used for spraying.

3.5.1.3 Harvesting and storage

Fruits were harvested on 10 October at the commercially mature stage, sorted to

eliminate damaged or shriveled fruit, further selected for uniform size and color. Fruits

were stored at 8˚C under normal air at 80-90% relatively humidity.

34


Fruit were surface-sterilized with 2% (v/v) sodium hypochlorite for 3 min dipping than

washed with tap water and air-dried. Each treatment contained three replications (10

fruits) and the entire experiment was performed twice.

3.5.1.5. Treatments layout

T0 = Distilled water applied

T1 = Salicylic acid (SA) @ 6.0 mM



T4 = Methyl Jasmnate (MeJA) @ 3 mM



All the quality parameters were estimated as mentioned in the section 3.4.1 and similar

procedure was adopted for their analysis.

3.5.1 Experiment-5b Effects of pre-harvest spray of salicylic (SA) and Methyl

Jasmonate (MeJA) on the chilling injury, decay and

phytochemicals during the storage in grapefruit cv. Shamber

Same procedure and analysis of parameters were carried out as mentioned in the section

3.5.1a. However, Shamber cultivar was used in this experiment.

35

Perpation of SA and Me JA Foliar Spray SA

Foliar Spray Me JA After foliar

Spray

Slide-6 Preparation of (SA and Me JA) and spray ahead before 15 days of

harvesting of both cultivars

36

SA 12mM (Ray Ruby) SA 12mM (Ray Ruby)

Me JA 5mM (Ray Ruby) Me JA 5mM (Ray Ruby)

Slide-7 Effects of SA (12mM) on the quality and shelf life of Ray Ruby after 90 days

storage

37

MeJA 5mM (Shamber) MeJA 5mM (Shamber)

MeJA 5mM (Shamber) MeJA 5mM (Shamber)

Slide- 8 Effects of Me JA (5mM) on the quality and shelf life of Shamber after 90

days storage

38

(Ray Ruby) (Ray Ruby)

(Shamber )

(Shamber)

Slide- 9 Fruits developed fruit Colour after 90 days of storage for both cultivars at

8°C by application of both chemicals

39

Slide- 10 Decay and chilling injury rating scale during storage of grapefruit

40

3.1.1.3.7 Organoleptic evaluation

Organoleptic evaluation of the fruit for sourness, sweetness, taste and texture was

done using the Hedonin scale method of Peryam and Pilgrim (1957). Ten judges were

selected in the panel who were requested to score the above mentioned parameters using

the 9 point Hedonic scale, being like extremely and one dislike extremely as given under

Product: _____________ Variety: _________________ Storage period: __________

Name of Judge: _________________________ Signature: _______________

Instructions: (Please read the instructions carefully before filling blanks)

This is an organoleptic analysis form for the evaluation of different grapefruit

treatments.

Please follow the numerical system for scoring the samples.

Dislike extremely ---------------1 Like slightly--------------6

Dislike very much --------------2 Like moderately ---------7

Dislike moderately------------- 3 Like very much----------8

Dislike slightly -----------------4 Like extremely ----------9

Neither like nor dislike--------5

Please do not disturb the sequence of the samples provided.

Please wash the tongue before testing next sample, with water provided

Sample# Color Texture Taste Sourness Sweetness Overall quality

1

2

3

4

5

6

7

8

9

10

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3.1.1.3.8 Statistical analysis

Collected data were statistically analyzed using computer software MSTAT-C. Analysis

of variance was used to test the significance of variance. While difference among

treatment means were compared using LSD test (P=0.05) (Steel et al., 1996). Standard

errors (SE) were computed by MS-Excel and data were presented graphically using the

same program.

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Chapter-4

RESULT AND DISUSSION

4.1. Experiment-1 Effects of different harvesting dates on the quality and

shelf life of grapefruit

Results 4.1.1

4.1.1.1 Physical parameters

4.1.1.1.1 Fruit weight (g)

Statistical analysis regarding the fruit weight showed significant differences at P<0.05 for

harvesting dates, varieties and their interaction during both years (Table 4.1). Fruits those

were harvested in December showed significantly higher weights (430.00 & 406.67 g) as

compared to fruits those were harvested in September, October, November and January in

Ray Ruby and Shamber, respectively. While minimum fruit weights of 351.67 & 293.33 g

were noted in fruits those were harvested in the month of September in Ray Ruby and

Shamber cultivars during the both years, respectively.

4.1.1.1.2 Fruit diameter (mm)

The results pertaining to fruits diameter are given in Table 4.2 Statistical analysis showed

significant differences at P<0.05 regarding the harvesting dates and varieties while

interaction between them was found non-significant during the both years. Fruits harvested in

December showed significantly higher diameters (14.33 & 15.16 mm) than the fruits

harvested in September, October, November and January in both Ray Ruby and Shamber

cultivars, respectively. Whereas, fruits those were harvested in September showed minimum

fruit diameters of 10.00 & 11.66 mm in Ray Ruby and Shamber during both years,

respectively.

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Table 4.1 Effects of different harvesting dates and varieties on the fruit weight (g) of

Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012

Ray Ruby Shamber Mean Ray Ruby Shamber Mean

1st Sep. 351.67f 293.33h 322.50E 356.67f 298.33h 327.50E

1st Oct. 383.33d 313.33g 348.33D 388.33d 318.33g 353.33D

1st Nov. 403.33c 360.00e 381.67C 408.33c 365.00e 386.67C

1th

Dec. 430.00a 406.67c 418.33A 435.33a 412.00c 423.67A

1st Jan. 414.00 b 405.67c 409.83B 419.33b 410.67c 415.00 B

Means 396.47A 355.80 B 401.60A 360.87B

LSD value Varieties = 2.45, Harvesting date =

3.88, Interaction = 5.48

Varieties = 2.55, Harvesting date =


Mean sharing same letter in row or column are non-significant at 5% probability level (LSD)

Table 4.2 Effects of different harvesting dates and varieties on the fruit diameter (mm)

of Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 10.00 11.00 10.00D 12.00 13.00 11.66 D

1st Oct. 9.33 10.33 11.66C 11.33 12.00 12.66 C

1st Nov. 12.00 11.33 13.00B 14.00 14.00 13.66 B

1th

Dec. 13.66 12.66 14.33A 15.66 15.23 15.16 A

1st Jan. 12.66 11.66 12.83B 14.66 13.00 14.16 B

Means 11.86A 11.06B 11.23A 11.02B

LSD value Varieties = 0.47, Harvesting dates = 0.75

Interaction = NS

Varieties = 0.48, Harvesting date =

0.79, Interaction = NS


44

4.1.1.1.3 Peel weight (g)

Effects of Harvesting dates and varieties significantly differed for peel weight of harvests

dates with varieties interaction significant differences by regarding the peel weight in fruits of

both cultivars during the both years (Table 4.3). Higher peel weights of 125.00 & 121.00 g

was recorded in fruits those were harvested in the month of December as compared to the

fruits those were harvested in January, November, October and September in Ray Ruby and

Shamber during the both years, respectively. Lower peel weights (101.67 & 110.00 g) were

noted in fruits those were harvested in September during the both years in both cultivars,

respectively.

4.1.1.1.4 Rag weight (g)

Rag weight in fruits showed statistically significant differences at P<0.05 regarding the

effects of harvesting dates, varieties while interaction between them was found non-

significant in both cultivars during the both years (Table 4.4). Fruits those were harvested in

December showed lower peel weights (98.00 & 95.83 g) in both Ray Ruby and Shamber

cultivars during the both years, respectively. Higher rag weights of 113.00 & 111.00 g were

recorded in fruits those were harvested in the month of September in Ray Ruby and Shamber

during the both years, respectively.

4.1.1.1.5 Juice weight (g)

Statistical analysis regarding the juice weight in fruits showed significant differences at

P<0.05 for harvesting dates while non-significant results were found for varieties and their

interaction in both cultivars during the both years (Table 4.5). Fruit those were harvested in

December attained higher juice weights of 110.20 & 110.94 g and these were statistically at

par with fruits those were harvested in the month of January where juice weights were 108.56

& 108.45 g in during the both years, respectively. While lower juice weights (92.83 & 94.68

g) were noted in fruits those were harvested in September during the first and second season,

respectively.

45

Table 4.3 Effects of different harvesting dates and varieties on the fruit peel weight (g)


Harvesting

dates 2010-2011 2011-2012


1st Sep. 101.67 f 110.00 d 100.00 E 99.67 f 108.00e 95.50 E

1st Oct. 110.33 g 115.00 e 105.00 D 101.33g 110.00c 105.50 D

1st Nov. 120.00 c 118.00 c 110.00 C 113.00 c 115.00b 110.50 C

1th

Dec. 125.00 a 121.00 a 123.00 A 123.00 a 120.00a 123.00 A

1st Jan. 120.00 b 119.00 b 119.50 B 120.00 b 118.0d 120.00 B

Means 115.33 A 113.67 B 115.33 A 111.67 B

LSD value Varieties = 0.98, Harvesting dates = 1.55

Interaction = 2.19

Varieties = 1.04, Harvesting dates

= 1.64, Interaction = 2.33


Table 4.4 Effects of different harvesting dates and varieties on the fruit rag weight (g) of


Harvesting

dates 2010-2011 2011-2012


1st Sep. 115.33 110.67 113.00 A 113.33 108.67 111.00 A

1st Oct. 110.67 105.67 108.17 B 108.67 104.00 106.33 B

1st Nov. 105.00 100.00 102.50 C 103.00 97.33 100.17C

1th

Dec. 100.00 96.00 98.00 D 97.67 94.00 95.83 E 1

st Jan. 104.00 107.33 100.00 E 103.7 98.33 100.17 D

Means 106.80A 103.33B 104.9A 100.4B

LSD value Varieties = 0.32, Harvesting dates =



= 0.76, Interaction = NS


46

Table 4.5 Effects of different harvesting dates and varieties on the fruit juice weight (g)


Harvesting

dates 2010-2011 2011-2012


1st Sep. 93.84 91.81 92.83D 95.10 94.26 94.68E

1st Oct. 97.74 96.96 97.35C 98.29 98.58 98.44D

1st Nov. 100.26 102.88 101.57B 102.02 103.03 102.53C

1th

Dec. 110.55 109.85 110.20A 111.96 109.92 110.94A

1st Jan. 108.92 108.19 108.56A 109.30 107.60 108.45B

Means 102.26 101.94 103.33 102.68

LSD value Varieties = NS, Harvesting dates = 2.04

Interaction = NS

Varieties = NS, Harvesting dates =



4.1.1.1.6 Number of seeds

Effects of harvesting dates, varieties and their interaction showed statistically non-significant

differences regarding the number of seeds in fruits of Ray Ruby and Shamber cultivars during

the both years (Table 4.6).

Table 4.6 Effects of different harvesting dates and varieties on the number of seeds in


Harvesting

dates 2010-2011 2011-2012


1st Sep. 6.00 5.33 5.66 6.33 6.33 6.33

1st Oct. 5.33 5.33 5.33 6.33 5.66 6.00

1st Nov. 5.66 6.66 6.16 5.33 6.00 5.66

1th

Dec. 5.33 5.33 5.33 6.66 6.66 6.66

1st Jan. 5.00 5.33 5.33 6.66 6.33 6.50

Means 5.46 5.60 6.26 6.20

LSD value Varieties = NS, Harvesting dates = NS

Interaction = NS


NS, Interaction = NS


47

4.1.1.1.7 Healthy seeds

Statistically non-significant results were found regarding the harvesting dates, varieties and

interaction between them on number of healthy seeds in fruits of both cultivars during the

both years (Table 4.7).

Table 4.7 Effects of different harvesting dates and varieties on the number of healthy

seeds in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 2.66 2.66 2.66 2.33 3.00 2.66

1st Oct. 2.66 2.00 2.33 3.00 2.66 2.83

1st Nov. 2.33 4.00 3.16 2.33 2.33 2.33

1th

Dec. 2.00 2.00 2.33 3.33 4.66 4.00

1st Jan. 3.00 3.00 2.33 3.33 3.33 3.33

Means 2.40 2.73 3.20 2.86

LSD value Varieties = NS, Harvesting dates = NS,

Interaction = NS




4.1.1.1.8 Aborted seeds

The Analysed data presented in Table 4.8 showed statistically non-significant results for

harvesting dates, varieties and their interaction on number of aborted seeds in fruits of both

cultivars during the both years.

Table 4.8 Effects of different harvesting dates and varieties on the number of aborted

seeds in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 3.33 2.66 3.00 4.00 3.33 3.66

1st Oct. 2.66 3.33 3.00 3.33 3.00 3.16

1st Nov. 3.33 2.66 3.00 3.00 3.66 3.33

1th

Dec. 2.66 3.33 3.00 3.33 2.00 2.66

1st Jan. 3.33 2.33 2.83 3.33 3.00 3.16

Means 3.06 2.86 3.40 3.00


Interaction = NS




48

4.1.1.1.9 Oil glands (180 mm-2

)

Statistically significant differences were found regarding the harvesting dates, varieties and

their interaction on oil glands in fruits of Ray Ruby and Shamber during the both years (Table

4.9). Fruits those were harvested in the month of December showed higher oil glands (10625,

8440 & 10291, 7989 180 mm-2) in fruits as compared to fruits those were harvested in other

months (January, November, October & September) in both Ray Ruby and Shamber during

the during the first and second season, respectively. While minimum oil glands of 6893, 5856

& 6909, 6000 180 mm-2 were recorded in fruits those were harvested in November in both

cultivars during the both experimental years, respectively.

4.1.1.1.10 Fruit firmness (Nm2)

Firmness in fruits of Ray Ruby and Shamber showed significant differences regarding the

harvesting dates while no significant difference was found in varieties and their interaction

during the both years (Table 4.10). Lowe fruits firmness (0.582 & 0.593 Nm2) was noted in

fruits those were harvest earlier in the month of November during the both years,

respectively. Higher firmness of 0.871 & 0.845 Nm2 in fruits were recorded those were

harvested in the month of December and then gradually decreased with delay in fruit

harvesting up to January where firmness in fruits were 0.770 and 0.792 Nm2 in both cultivars

during the first and second season, respectively.

Table 4. 9 Effects of different harvesting dates and varieties on the oil glands (180 mm-2

)

in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 6893e 5856f 6374.30D 6909e 6000f 6454.50D

1st Oct. 7779cd 7000e 7389.20C 7780cd 7215de 7497.20C

1st Nov. 7967cd 7489de 7728.30C 7922c 7558cd 7740.00C

1th

Dec. 10625a 8440c 9532.70A 10291a 7989c 9144.80A

1st Jan. 9624b 7966cd 8795.00B 9520b 7818cd 8669.30B

Means 8577.70A 7350.10B 8484.40A 7317.90B


477.17, Interaction = 674.82

Varieties = 281.82, Harvesting

dates = 445.59, Interaction =

630.16


49

Table 4.10 Effects of different harvesting dates and varieties on the fruit firmness (Nm2)


Harvesting

dates 2010-2011 2011-2012


1st Sep. 0.60 0.56 0.58D 0.58 0.59 0.59D

1st Oct. 0.68 0.65 0.66C 0.68 0.65 0.60C

1st Nov. 0.71 0.69 0.70C 0.77 0.77 0.72B

1th

Dec. 0.87 0.86 0.87A 0.82 0.82 0.85A

1st Jan. 0.76 0.78 0.77B 0.79 0.79 0.79 AB

Means 0.72A 0.71B 0.73A 0.73B

LSD value Varieties = NS, Harvesting dates =





4.1.1.1.11 Pulp/peel ratio

Statistically no significant differences were found regarding the effects of harvesting dates,

varieties and their interaction on pulp/peel ratio in fruits of Ray Ruby and Shamber cultivars

during the both years (Table 4.11).

4.1.1.1.12 Number of segments

The analysed data presented in Table 4.12 showed statistically non-significant differences for

harvesting dates, varieties and their interaction on number of segments in fruits of Ray Ruby

and Shamber cultivars, respectively during the both years.

50

Table 4.11 Effects of different harvesting dates and varieties on the peel/pulp ratio in


Harvesting

dates 2010-2011 2011-2012


1st Sep. 0.93 0.93 0.93 0.80 0.85 0.83

1st Oct. 0.96 0.91 0.93 0.82 0.82 0.82

1st Nov. 0.94 0.94 0.94 0.81 0.83 0.82

1th

Dec. 0.95 0.88 0.92 0.79 0.83 0.81

1st Jan. 0.95 0.96 0.96 0.87 0.83 0.85

Means 0.95 0.92 0.82 0.83


Interaction = NS




Table 4.12 Effects of different harvesting dates and varieties on the number of segments


Harvesting

dates 2010-2011 2011-2012


1st Sep. 12.33 13.66 13.00 12.33 12.33 12.33

1st Oct. 13.66 12.00 12.83 12.00 14.00 13.00

1st Nov. 13.66 12.66 13.16 11.66 14.00 12.83

1th

Dec. 12.66 13.66 13.16 12.66 11.33 12.00

1st Jan. 12.33 10.66 11.50 13.66 12.66 13.16

Means 12.93 12.53 12.46 12.86


Interaction = NS




51

4.1.1.2 Biochemical parameters

4.1.1.2.1 pH of fruit juice

Statistically significant differences were found regarding the harvesting dates while both

varieties and their interaction showed non-significant results on pH of juice in fruits of Ray

Ruby and Shamber during the both years (Table 4.13). Fruits of both cultivars those were

harvested in the month of December showed higher pH of 5.81 & 5.59 in fruits followed by

fruits those were harvested in January and November and these were statistically at par with

each other during the first and second season, respectively in both cultivars. However, lower

pH in juice (3.70 & 3.65) was noted in fruits those were harvested in the month of November

during the both years, respectively in both cultivars.

4.1.1.2.2 Total soluble solids (oBrix)

Total soluble solids in fruits showed significant differences regarding the harvesting dates

and varieties while their interaction was found non-significant during the both years (Table

4.14). Fruits those were harvested in the month of December showed higher TSS contents of

9.66 & 9.81 oBrix followed by fruits those were harvested in January and November where

TSS in fruits were 8.63, 9.18, 8.50 and 8.72 oBrix during the first and second season,

respectively. While, lower TSS contents (5.46 & 5.56 oBrix) in fruits were noted those were

harvested in November during the both study years, respectively in both cultivars.

Table 4.13 Effects of different harvesting dates and varieties on the pH of juice in Ray

Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 3.85 3.56 3.70C 3.77 3.52 3.65C

1st Oct. 4.22 4.14 4.18 C 4.44 4.39 4.42B

1st Nov. 4.70 4.92 4.81 B 4.80 4.59 4.69B

1th

Dec. 5.53 6.09 5.81 A 5.34 5.84 5.59A

1st Jan. 4.81 5.26 5.04 B 4.77 5.40 5.08AB

Means 4.62 4.79 4.62 4.75






52

Table 4.14 Effects of different harvesting dates and varieties on the total soluble solids

(oBrix) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 5.03 5.89 5.46D 5.32 5.80 5.56E

1st Oct. 6.69 6.83 6.76C 6.40 7.15 6.78D

1st Nov. 8.34 8.65 8.50B 8.48 8.96 8.72C

1th

Dec. 9.43 9.88 9.66A 9.63 9.99 9.81A

1st Jan. 8.51 8.75 8.63B 9.10 9.25 9.18B

Means 7.60B 8.00A 7.79B 8.23A



Varieties = 0.192, Harvesting dates =



4.1.1.2.3 Total titratable acidity (%)

Results presented in Table 4.15 showed statistically significant differences for harvesting

dates while varieties and their interaction did not differ significantly regarding the total

titratable acidity in fruits of Ray Ruby and Shamber during the both years. Lower level of

titratable acidity (1.293 & 1.226%) in fruits were noted those were harvested in the month of

December and then increased as the fruit harvesting was delayed up to January where

titratable acidity was 1.465 & 1.451% in fruits during first and second season, respectively.

Fruits harvested in November attained higher titratable acidity of 1.895 & 1.826% during the

both years, respectively.

4.1.1.2.4 TSS/acidity ratio

Statistically significant results were found regarding the effects of harvesting dates and

varieties while interaction between them was found non-significant for TSS/acidity ratio in

fruits during the both years (Table 4.16). Fruits those were harvested in the month of

December showed higher TSS/acidity ratio of 7.47 & 8.00 followed by fruits those were

harvested in January and November during the both years, respectively. While, lower

TSS/acidity ratio was noted in fruits those were harvested in November where TSS/acidity

ratio was 2.88 & 3.04 during the both study years, respectively. The fruits of Shamber

showed higher TSS/acidity ratio (5.34 & 5.54) than the fruits of Ray Ruby where TSS/acidity

ratios were 4.98 & 5.32 during the both years, respectively.

53

Table 4.15 Effects of different harvesting dates and varieties on the total titratable

acidity (%) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 1.91 1.87 1.89A 1.82 1.82 1.82A

1st Oct. 1.76 1.73 1.74B 1.59 1.64 1.66B

1st Nov. 1.50 1.48 1.49C 1.54 1.56 1.55C

1th

Dec. 1.30 1.28 1.29D 1.20 1.25 1.22E

1st Jan. 1.48 1.44 1.46C 1.47 1.43 1.45D

Means 1.59 1.56 1.52 1.54






Table 4.16 Effects of different harvesting dates and varieties on the TSS/acidity ratio in


Harvesting

dates 2010-2011 2011-2012


1st Sep. 2.63 3.13 2.88D 2.91 3.18 3.04E

1st Oct. 3.80 3.94 3.87C 4.02 4.35 4.19D

1st Nov. 5.54 5.85 5.69B 5.49 5.72 5.60C

1th

Dec. 7.22 7.73 7.47A 8.00 8.00 8.00A

1st Jan. 5.73 6.07 5.90B 6.19 6.47 6.33B

Means 4.98B 5.34A 5.32B 5.54A






54

4.1.1.2.5 Ascorbic acid (mg/100 g)

Statistically significant results were found regarding the effects of harvesting dates while

varieties and their interaction showed non-significant differences for ascorbic acid contents in

fruits during the both years (Table 4.17). Higher amounts of ascorbic acid of 40.27 & 40.44

mg/100 g in fruits were noted those were harvested in December followed by fruits those

were harvested in the months of January and November and these were statistically at par

with each other during first and second season, respectively. Minimum ascorbic acid contents

(30.59 & 30.39 mg/100 g) were found in fruits those were harvested in November during the

both years, respectively.

4.1.1.2.6 Total sugars (%)

Total sugar contents in fruits showed statistically significant differences regarding the

harvesting dates and varieties while interaction between them was found non-significant

during the both years (Table 4.18). Fruits of Shamber showed higher total sugars of 6.11 &

6.27% as compared to the fruits of Ray Ruby where total sugar contents were 6.01 & 6.16%

during the both years, respectively. Fruits harvested in the month of December showed higher

total sugar contents of 6.99 & 6.96% in fruits followed by fruits those were harvested in

January and November where total sugars were 6.48, 6.71 & 6.33, 6.52% during the both

years, respectively. Lower amount of total sugar contents (4.28 & 4.44%) were noted in fruits

those were harvested in November during both years, respectively.

Table 4.17 Effects of different harvesting dates and varieties on the ascorbic acid

contents (mg/100 g) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 30.56 30.63 30.59D 30.62 30.29 30.45D

1st Oct. 33.67 34.06 33.86C 33.37 34.21 33.79C

1st Nov. 36.73 36.98 36.86B 36.76 37.47 37.11B

1th

Dec. 39.65 40.89 40.27A 40.41 40.48 40.44A

1st Jan. 37.44 38.22 37.83B 37.62 38.00 37.81B

Means 35.61 36.15 35.75 36.09

LSD value Varieties = NS, Harvesting dates = 1.31,

Interaction = NS




55

Table 4.18 Effects of different harvesting dates and varieties on the total sugars (%) in


Harvesting

dates 2010-2011 2011-2012


1st Sep. 4.21 4.35 4.28E 4.38 4.51 4.44D

1st Oct. 6.14 6.31 6.22D 6.37 6.51 6.44C

1st Nov. 6.23 6.43 6.33C 6.42 6.62 6.52C

1th

Dec. 7.03 6.95 6.99A 6.95 6.97 6.96A

1st Jan. 6.43 6.53 6.48B 6.66 6.75 6.71B

Means 6.01B 6.11A 6.16B 6.27A






4.1.1.2.7 Reducing sugars (%)

Effects of harvesting dates and varieties showed statistically significant differences while

interaction between them was found non-significant regarding the reducing sugar contents in

fruits of Ray Ruby and Shamber cultivars during the both years (Table 4.19). Higher amounts

of reducing sugar contents (5.66 & 5.33%) were recorded in fruits those were harvested in the

month of December followed by fruits those were harvested in January and November and

these were statistically at par with each other during the first and second season, respectively.

Whereas, lower amounts of reducing sugar contents of 3.16 & 3.09 % were noted in fruits

those were harvested in September during the both years, respectively. Regarding the

response of cultivars, Shamber showed higher reducing sugar contents of 4.82 & 4.56% as

compared to the fruits of Ray Ruby where reducing sugar contents were 4.69 & 4.34% during

the first and second season, respectively.

4.1.1.2.8 Non-reducing sugars (%)

Statistically significant results were found regarding the effects of harvesting dates and

varieties while interaction between them showed non-significant results for non-reducing

sugars in fruits during the both years (Table 4.20). Fruits harvested in the month of December

showed higher amounts of non-reducing sugars of 2.063 & 1.955% followed by fruits those

were harvested in January and November where non-reducing sugars were 1.686, 1.610 &

1.628, 1.556% during the both years, respectively. While, lower amounts of non-reducing

sugars (1.243 & 1.281%) were noted in fruits those were harvested in September during the

both years, respectively. Fruits of Ray Ruby showed higher non-reducing sugars of 1.650 &

56

1.617% as compared to those fruits of Shamber where non-reducing sugars were 1.574 &

1.546 during the first and second season, respectively.

Table 4.19 Effects of different harvesting dates and varieties on the reducing sugar (%)


Harvesting

dates 2010-2011 2011-2012


1st Sep. 3.11 3.22 3.16D 3.02 3.17 3.09D

1st Oct. 4.80 4.95 4.87C 4.34 4.58 4.46C

1st Nov. 4.90 5.07 4.99BC 4.49 4.72 4.61BC

1th

Dec. 5.59 5.73 5.66A 5.26 5.41 5.33A

1st Jan. 5.04 5.16 5.10B 4.62 4.91 4.76B

Means 4.69B 4.82A 4.34B 4.56A






Table 4.20 Effects of different harvesting dates and varieties on the non-reducing sugars

(%) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 1.260 1.226 1.243D 1.306 1.256 1.281D

1st Oct. 1.470 1.410 1.440C 1.536 1.476 1.506C

1st Nov. 1.663 1.593 1.628B 1.570 1.543 1.556BC

1th

Dec. 2.133 1.993 2.063A 2.043 1.866 1.955A

1st Jan. 1.723 1.650 1.686B 1.630 1.590 1.610B

Means 1.650A 1.574B 1.617A 1.546B






57

4.1.1.3 Phytochemical parameters

4.1.1.3.1 Total phenolic contents (mg GAE/100 g)

Total phenolic contents in fruits showed statistically significant differences regarding the

effects of harvesting dates and varieties while interaction between them was found non-

significant during the both years (Table 4.19). Fruits harvest in the month of December

showed higher TPC of 172.25 & 176.95 mg GAE/100 g in fruits followed by fruits those

were harvested in January and November where TPC were 147.47, 150.30 & 135.98, 145.95

mg GAE/100 g during the first and second season respectively. Lower TPC values (101.49 &

101.74 mg GAE/100 g) were noted in fruits those were harvested in the month of November

during the both years, respectively. Shamber showed higher TPC of 144.39 & 151.44 mg

GAE/100 g in fruits as compared to the fruits of Ray Ruby where TPC were 125.72 & 128.22

mg GAE/100 g during the both years.

4.1.1.3.2 Total antioxidants (% DPPH inhibition)

Statistically significant differences were found for harvesting dates and varieties while

interaction showed non-significant results on total antioxidants in fruits during the both years

(Table 4.20). Higher antioxidants activities of 76.36 & 75.08% in fruits were noted those

were harvested in December followed by fruits those were harvested in the months of January

and November during the both years, respectively. However, lower antioxidants (30.52 &

28.66%) were recorded in fruits those were harvested in September during the both years,

respectively. Ray Ruby showed lower antioxidants of 54.94 & 53.45% in fruits as compared

to the fruits of Shamber where antioxidants were 60.98 & 58.53% during the both

experimental years, respectively.

58

Table 4.21 Effects of different harvesting dates and varieties on the total phenolic

contents (mg GAE/100 g) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 90.59 112.40 101.49C 97.70 105.78 101.74D

1st Oct. 111.25 125.06 118.15C 119.65 128.73 124.19C

1st Nov. 128.99 142.80 135.89B 133.33 158.77 145.95B

1th

Dec. 159.36 185.14 172.25A 153.80 200.10 176.95A

1st Jan. 138.40 156.14 147.47B 136.80 163.81 150.30B

Means 125.72B 144.39A 128.22B 151.44A






Table 4.22 Effects of different harvesting dates and varieties on the total antioxidants

activities (% DPPH inhibition) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 28.40 32.65 30.52D 22.29 35.03 28.66D

1st Oct. 44.76 49.73 47.24C 50.17 44.73 47.45C

1st Nov. 59.54 65.37 62.45B 59.50 63.83 61.67B

1th

Dec. 72.47 80.26 76.36A 72.14 78.03 75.08A

1st Jan. 69.54 76.91 73.22A 63.17 71.03 67.10B

Means 54.94B 60.98A 53.45B 58.53A






59

4.1.1.3.3 Total flavonoids (mg CEQ/100 g)

Effects of harvesting dates and varieties showed statistically significant results while

interaction between them was found non-significant regarding the total flavonoids contents in

fruits during the both years (Table 4.21). Fruits harvested in the month of December showed

higher total flavonoids contents of 65.28 & 69.16 mg CEQ/100 g followed by fruits those

were harvested in January and November where total flavonoids were 58.00, 63.76 & 54.47,

57.50 mg CEQ/100 g during the both years, respectively. Lower total flavonoids (23.19 &

29.06 mg CEQ/100 g) were noted in fruits those were harvested in September during the both

years, respectively. The fruits of Shamber showed higher TFC of 49.49 & 56.35 mg CEQ/100

g than the fruits of Ray Ruby where TFC were 44.92 & 48.13 mg CEQ/100 g during the both

years, respectively.

4.1.1.3.4 Total carotenoids (mg/100 g)

Total carotenoids in fruits showed significant differences regarding the effects of harvesting

dates and varieties while interaction between them did not differ significantly during the both

years (Table 4.22). Higher amounts of total carotenoids (20.05 & 20.76 mg/100 g) in fruits

were recorded those were harvested in December as compared to fruits those were harvested

in January, November, October and September during the both years, respectively. Whereas,

lower carotenoid contents of 9.53 & 10.88 mg/100 g in fruits were noted those were

harvested in the month of September during the both years, respectively. Shamber fruits

showed higher total carotenoids of 16.29 & 16.38 mg/100 g than the fruits of Ray Ruby

where total carotenoids were 15.18 & 15.23 mg/100 g during the both study years,

respectively

60

Table 4.23 Effects of different harvesting dates and varieties on the total flavonoids

contents (mg CEQ/100 g) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 19.29 27.09 23.19D 26.09 32.03 29.06E

1st Oct. 31.09 39.10 35.10C 35.40 48.06 41.73D

1st Nov. 52.94 56.00 54.47B 60.24 60.24 57.50C

1th

Dec. 64.76 65.80 65.28A 74.00 74.00 69.16A

1st Jan. 56.54 59.47 58.00B 67.43 67.43 63.76B

Means 44.92B 49.49A 48.13B 56.35A






Table 4.24 Effects of different harvesting dates and varieties on the total carotenoids

(mg/100 g) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 8.84 10.22 9.53E 9.77 11.99 10.88D

1st Oct. 13.72 14.91 14.31D 14.25 14.95 14.60C

1st Nov. 16.59 17.02 16.80C 15.80 15.50 15.65C

1th

Dec. 19.03 21.07 20.05A 19.46 22.07 20.76A

1st Jan. 17.70 18.26 17.98B 16.89 17.40 17.14B

Means 15.18B 16.29A 15.23B 16.38A






61

4.1.1.3.5 Total pectin contents (%)

Statistically significant differences were found for harvesting dates while varieties and their

interaction showed non-significant results on total pectin contents in fruits during the both

years (Table 4.23). Fruits harvested in December showed higher total pectin contents of 10.96

& 10.51% as compared to fruits those were harvested in the months of January, November,

October and September during the first and second season, respectively. Lower total pectin

contents (4.73 & 5.00%) in fruits were noted those were harvested in September during the

both years, respectively. Shamber showed higher total pectin contents of 7.89 & 8.23% than

the fruits of Ray Ruby where total pectin contents were 7.78 7 8.11% during the both years,

respectively.

4.1.1.3.6 Total limonin contents (µg/mL)

Effects of harvesting dates and varieties and their interaction were found statistically

significant regarding the total limonin contents in fruits during the both years (Table 4.24).

Higher amounts of total limonin contents of 14.88, 13.13 & 14.44, 12 32 µg/mL were

recorded in fruits those were harvested in September followed by fruits those were harvested

in the month of October, November, December and January during the first and second

season respectively. While, lower total limonin contents (9.29, 8.67 & 9.66, 9.14 µg/mL)

were recorded in fruits those were harvested in December in both cultivars during the both

years, respectively. Fruits of Ray Ruby showed higher limonin contents of 11.88 & 11.93

µg/mL as compared to the fruits of Shamber where total limonin contents were 10.77 &

10.96 µg/mL during the both years, respectively.

Table 4.25 Effects of different harvesting dates and varieties on the total pectin contents

(%) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 4.68 4.78 4.73D 4.98 5.03 5.00D

1st Oct. 6.14 6.28 6.21C 7.22 7.35 7.28C

1st Nov 8.47 8.54 8.51B 7.65 7.74 7.69B

1th

Dec 10.88 11.04 10.96A 10.43 10.58 10.51A

1st Jan. 8.47 8.79 8.67B 10.29 10.45 10.37A

Means 7.78 7.89 8.11 8.23






62

Table 4.26 Effects of different harvesting dates and varieties on the total limonoids

contents (µg/mL) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 14.88a 13.13b 14.00A 14.44a 12.32c 13.38A

1st Oct. 13.32b 11.44c 12.38B 13.66b 12.47c 13.06A

1st Nov 11.73c 10.66d 11.19C 11.51d 10.67e 11.09B

1th

Dec 9.29fg 8.67g 8.98E 9.66fg 9.14g 9.40D

1st Jan. 10.18de 9.95ef 10.07D 10.40e 10.20ef 10.30C

Means 11.88A 10.77B 11.93A 10.96B




= 0.455, Interaction = 0.644


4.1.1.3.7 Total glycoside limonin contents (µg/mL)

Total glycoside limonin contents (TGLC) in fruits showed significant differences regarding

the effects of harvesting dates and varieties while interaction between them was found non-

significant during the both years (Table 4.25). Fruits harvested in the month of December

showed higher glycoside limonin contents (202.19 & 197.18 µg/mL) followed by fruits those

were harvested in January and November where TGLC were 194.54, 191.74 & 188.27,

188.01 µg/L during the first and second season, respectively. However, lower amounts of

TGLC of 174.39 & 171.48 µg/mL were noted in fruits those were harvested in September

during the both years, respectively. The fruits of Shamber showed higher TGLC of 191.07 &

190.23 µg/L as compared to the fruits of Ray Ruby where TGLC were 185.71 & 181.43

µg/mL during the both experimental years, respectively.

63

Table 4.27 Effects of different harvesting dates and varieties on the total glycoside

limonin contents (µg/mL) in Ray Ruby and Shamber fruits.

Harvesting

dates 2010-2011 2011-2012


1st Sep. 172.07 176.70 174.39E 169.82 173.13 171.48D

1st Oct. 181.30 183.78 182.54D 178.45 182.99 18072C

1st Nov 186.14 190.41 188.27C 183.01 193.02 188.01B

1th

Dec 197.97 206.40 202.19A 190.98 203.38 197.18A

1st Jan. 191.04 198.04 194.54B 184.87 198.62 191.74AB

Means 185.71B 191.07A 181.43B 190.23A



Varieties = 3.64, Harvesting dates =



4.1.2 Discussion

It is well known that a good eating quality fruits can be achieved when fruits are

harvested at proper stage of maturity. The harvesting of grapefruit in Pakistan is started in

July and continues up to late March. To investigate the nutritional status, fruits were

harvested in middle five months and analysed. The physical and chemical parameters of fruits

are the important indicators of their maturation for internal and external quality, decisive

factors for accomplishment of market demands. Maximum values of physiological

parameters (Roberts and Gordon, 2003) increased up to December and fruits harvested later

in January were significantly reduced their weights. The increase up to December is well

known because the growth or development of fruit continued due to the cell division and cell

enlargement and due to more photosynthesis assimilates and translocation to fruits because

fruit remained more time on plant (Ali et al., 2010). Many researches earlier quoted same

findings that fruit weight increased significantly with the delayed harvesting (Cepeda et al.,

1993; Mc Doland, 1998; Rice-Evans, 1997; Grosser and Chandler, 2000; Vinson et al., 2001;

Chuine and Rousseu, 1998).

Maximum fruit diameter was recorded in Ray Ruby fruit compared with Shamber

which might be due to the genetic variation. It might be possible that fruits of Ray Ruby

completed their processes related to assimilation of carbohydrates and cell enlargement faster

and quicker than the fruits of Shamber because fruit size increase due to proper assimilation

and cell enlargements (Ahmed et al., 2012). Maximum peel weight was recorded in Ray

Ruby in month of December. The reason might be the same as explained above and this

64

explanation is also supported by the findings of Aznar et al. (1995) who reported that of cell

expansion increased the vesicle capacity for juice accumulation therefore the fruit growth

was faster. Fruit harvested in month of December showed maximum juice contents for both

varieties has the similar explanation as peel which is understood because a larger fruit size is

due to the increase cell expansion and expands cells has an ability to increase the vesicles

capacity for juice accumulation. Fruits those were harvested in later dates showed reduction

of juice due to more transpiration and respirational changes take place in fruits (Reuther and

Rios-Castano, 1969). No significant differences were noted regarding the number of seeds,

healthy and aborted seeds during all harvesting dates. It might be due to reason that fruit

attained seed in early dates then no change occurred in later harvesting dates (Ahmed et al.,

2012). Fruit those were harvested in December showed maximum segment for both varieties.

These findings are supported with findings of pervious scientists those noted that fruit weight

increased significantly with the delayed harvesting (Cepeda et al., 1993; Miller and Rice-

1942; Evans, 1997; Grosser and Chandler, 2000; Chuine and Rousseu, 1998).

Maximum oil glands were noted in Ray Ruby fruits than fruit of Shamber during both

years of experimentation. Fruit harvest in December showed maximum oil glands due to

gland initiation restricted to early fruit development and ceasing at a fruit size of

approximately of 20 mm diameter. This reasons appropriated by the finding of Ford (1942)

who reported that gland initiation from started in the 'cell division' stage of fruit development

and continued up to a fruit size of 16 mm. However, our findings refute the statement of

Schneider (1968) who suggested that oil glands continued to form as the citrus fruit matured.

Mature glands enlarged with fruit growth as had been observed previously in Washington

Navel orange (Holtzhausen, 1969) and Valencia orange (Bain, 1958). Early harvesting dates

showed lower oil gland on fruit surface due to improper fruit size and structure (Turner et al.,

1998).

Fruit softening is often used as indicator for selecting the most suitable maturity index

of fruits. Fruit harvested in December showed more fruit firmness as compared to fruit

harvested in early stage. However, surprisingly early harvesting dates showed lower level of

cellulose and hemicelluloses in cell wall in flavedo tissue, sugar concentration was highest in

the cellulose fraction, and lowest in the hemicelluloses fraction. The concentration in all

fractions decreased as the fruit developed and matured as reported by Taylor et al. (1995) and

(Lehman and Salada, 1996).

Fruit harvested in December showed maximum pH of juice values as compared to

fruit harvested in early months during both year of study which might be due to more water

65

contents in fruit which correlated to fruit developmental stages. Our result is matched with

Reuther and Riocastano (1969) statement that initial acidity raised than decrease pH of fruits

those were absorbs more water and evaporation rapidly caused to raised pH of juice. Cepeda

et al. (1993) who reported increased pH in Valencia late juice due to delay harvesting date.

Fruit marketable quality is largely determined by the stage of development of fruit and

harvest time. Fruit harvested in December showed higher Total soluble solid contents as

compared to fruit those were harvested in early and January. The concentrations of titratable

acids in gradually decrease as the fruit develops and full mature. Vitamin C in juice

decreased as the season advanced. Our results in agreement with those of Reuther et al.

(1969) and Jungsakulrujirek and Noomhorm (1998) who noticed a distinct declining trend in

titratable acidity as maturation progressed Ahmad et al. (1992). Rizzolo and Eccher (2006)

and Ahmad et al. (1992) reported changes in fruit internal quality (e.g., TSS, acidity, ascorbic

acid, total, reducing and non-reducing sugars, and the sugar/acid ratio) of three grapefruit

cultivars with different harvesting dates. During growth and maturation stages of fruits, the

nutritional attributes particularly sugar were changed; therefore total soluble solid content

increased and moisture content decreased. Sugar during maturation stage of fruits is not only

the consequence of starch hydrolysis but also the result of hemicellulose hydrolysis. During

hydrolysis, hemicellulose is converted to xilose, manose, galactose, arabinose; while cell

structure is destroyed. Our result agreed with the findings of (Kriedemann, 1969).

Grapefruit contains significant levels of biologically active components with

physiological and biochemical functions on human body. It is an excellent food characterized

by a low content of calories. Maximum TPC were found in December fruit as compared to

fruit harvested in January due to series of chemical and enzymatic changes like glycoside

hydrolysis by glycosidase, phenolic compounds oxidation by phenol oxidizes and

polymerization of free phenolic compounds. Early harvesting dates and January showed

lower values of TPC due to reduction in these phenolic compounds is a symptom of ripening

in most fruits. It seems that the role of phenolic compounds in mature fruits refers to defense

mechanism. Our result matched with the findings of different scientist who reported same

concept (Andreotti et al., 2008; Remorini et al., 2008). Fruit harvested in December showed

higher antioxidants as compared to fruit harvested in early months and January due to fast

ripening and directly correlated with maturity. The levels of phenolic compounds and total

antioxidants capacity increased significantly with maturation, as did the antioxidant capacity,

which was directly proportional to the levels of these compounds. Our result matched with

the results of (Andreotti et al., 2008; Remorini et al., 2008).

66

Citrus is a complex source of carotenoids with the largest number of carotenoids

found in juice. Maximum contents of total flavonoids and total carotenoids were recorded in

the fruits harvested in December than the fruit. Early harvesting dates and January showed

reduction in these compounds was noted due to higher process of ripening which reduced the

TC, TF contents in fruit. Our result matched with (Grierson and tucker 1983), (Goodner et al.

(2001) Pectin substances are cellulose constitutes of the plant cell wall and plays an important

role in changing the texture of fruit tissue. Maximum pectin values were observed in fruits

harvested in December compared to the fruit harvested early dates and January. During the

maturation process the more enzymatic activities enhances such as pectin esterase which

responsible for different cell wall changes. Early harvested fruit showed reduction of pectin

related enzyme for lower cell wall change take place in fruit (Gross, 1987; Do et al.,;

Callahan et al., 2004). Fruit harvested in December showed higher TL, TGL contents as

compared to fruit harvested in other months. Many naturally occurring glycosidated

compounds, which appear to be biologically inactive, accumulate and are stored in mature

fruit tissues and seeds but TGL increased constant due to link with sugar contents. Lower

contents of both these compound was noted in early harvested fruits and January due to

change in antioxidant and more metabolic change take place in fruits Goodner et al., 2001;

Ikoma et al.,1996; Lee and Castle, 2001).

4.1.3 Conclusion

Quality management is the most limiting factor for lower production in Pakistan. Improved

quality can be achieved with full mature fruits should be harvest. It can conclude that fruit

should be harvested at full maturity stage especially during the month of December.

• The fruits harvested in month of December showed higher biochemical constituents

as compared to the fruits those harvested during September, October, and November

and during January.

• Harvested in December showed maximum fruit weight with highest amount of all

essential phytonutrients (TPC,TAA,TP,TC,TF,TL and TGL), other quality parameters

(TSS, lower fruit firmness ,Vit C, TS, RS and NRS.).

• Varieties showed difference response regarding their quality parameter. (TPC, TAA,

TGL, sugars, TSS, vitamin C Shamber ) Ray Ruby contained maximum (TC, TFC,

TPC).

67

4.2. Experiment-1 (a) Effects of cold storage and tree storage (delayed

harvesting) relating to their quality and shelf life of

grapefruit Cv. Ray Ruby

Results 4.2.1a

4.2.1.1a Biochemical parameters

4.2.1.1.1a pH of juice

Statistically significant differences were found regarding the effects of storage treatments,

storage periods and their interaction on pH of juice in fruits of Ray Ruby cultivar (Figure

4.28a). Higher pH of 5.17 was noted in fruits those were stored at 8oC as compared to the

fruits those were stored at 6oC and held on tree where pH values in fruits were 4.53 and 3.38,

respectively. Regarding the response of storage periods, maximum pH of 4.99 was noted in

fruits those were analysed after 90 days period than the fruits those were analysed after 60

and 30 days where pH values in fruits were 4.34 and 3.77, respectively. The interaction

between storage treatments and storage periods showed higher pH of 6.67 in fruits those were

stored at 8oC and analysed after 90 days. Whereas, lower pH of 2.88 was noted in fruits those

were stored on tree and analysed after 90 days and these were statistically at par with fruits

those were stored on tree and analysed after 60 days period where pH was 3.15 in fruits of

Ray Ruby.

4.2.1.1.2a Total soluble solids (oBrix)

Total soluble solids in fruits of Ray Ruby showed statistically significant differences

regarding the effects of storage treatments, storage periods and their interaction (Figure

4.29a). Fruits those were stored at 8oC showed higher TSS contents of 7.50 oBrix as

compared to fruits those were stored at 6oC and held on tree where TSS contents in fruits

were 6.89 and 5.77 oBrix, respectively. Maximum TSS contents of 7.21 oBrix were noted in

fruits those were analysed after 90 days than the fruits those were analysed after 60 and 30

days periods where TSS contents were 6.75 and 6.20 oBrix. The interaction effect between

storage treatments and storage periods showed that higher TSS contents (8.75 oBrix) were

recorded in fruits those were stored at 8oC were analysed after 90 days. While, lower TSS of

4.98 oBrix was noted in fruits those were stored on tree and analysed after 90 days period.

68

Figure 4.28a Effects of cold storage (CS) and tree storage (TS) on pH in fruits of

Ray Ruby analysed after 30, 60 and 90 days periods.

Each vertical bar represents mean of three replicates ± S.E.

Figure 4.29a Effects of cold storage (CS) and tree storage (TS) on total soluble

solids (oBrix) in fruits of Ray Ruby analysed after 30, 60 and 90

days periods.


0

1

2

3

4

5

6

7

8

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS

30 DAS 60 DAS 90 DAS

pH

of

juic

e

pH at 0 days = 3.00

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TS

S (

oB

rix

)

TSS at 0 day = 5.16 °Brix

69

4.2.1.1.3a Total titratable acidity (%)

The effects of storage treatments, storage periods and their interaction showed statistically

significant differences for total titratable acidity in fruits of Ray Ruby cultivar (Figure 4.30

a). Lower titratable acidity contents of 1.47% were noted in fruits those were stored in cold

storage at 8oC than the fruits those were stored at 6oC and held on tree where titratable acidity

was 1.58 and 1.69% in fruits of Ray Ruby. Fruits those were analysed after 90 days showed

lower titratable acidity (1.54%) and that was statistically at par with fruits those were

analysed after 60 days followed by 30 days where titratable acidity was 1.58 and 1.62% in

fruits of Ray Ruby, respectively. The interactive effect of storage treatments and storage

periods showed that lower titratable acidity of 1.31% was noted in fruits those were stored at

8oC and analysed after 90 days period. Whereas, higher titratable acidity of 1.87% was

recorded in fruits those were stored on tree and analysed after 90 days in Ray Ruby cultivar.

4.2.1.1.4a TSS/acidity ratio


storage periods and their interaction on TSS/acidity ratio in fruits of Ray Ruby cultivar

(Figure 4.31 a). Fruits those were stored at 8oC showed higher TSS/acidity ratio of 5.21 as

compared to fruits those were stored at 6oC and held on tree where TSS/acidity was 4.43 and

3.46, respectively. Maximum TSS/acidity (4.94) was noted in fruits those were analysed after

90 days period than the fruits analysed after 60 and 30 days where TSS/acidity was 4.32 and

3.84, respectively. The interaction effect between storage treatments and storage periods

showed that higher TSS/acidity of 6.66 was recorded in fruits those were stored at 8oC and

analysed after 90 days. While, minimum TSS/acidity (2.66) was noted in fruits those were

stored on tree and analysed after 90 days.

70

Figure 4.30a Effects of cold storage (CS) and tree storage (TS) on total

titratable acidity (%) in fruits of Ray Ruby analysed after 30, 60



Figure 4.31a Effects of cold storage (CS) and tree storage (TS) on TSS/acidity

ratio in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS

30 Days 60 Days 90 Days

Acid

ity (

%)

Acidity at 0 day 2.16%

0

1

2

3

4

5

6

7

8

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TS

S/a

cid

ity

TSS/Acidty at 0 days =3.92

71

4.2.1.1.5a Ascorbic acid (mg/100 g)

Ascorbic acid contents showed significant differences regarding the effects of storage

treatments, storage periods and their interaction in fruits of Ray Ruby (Figure 4.32 a).

Maximum ascorbic acid contents of 37.13 mg/100 g were noted in fruits those were stored at

8oC than the fruits those were stored at 6oC and held on tree where ascorbic acid contents

were 35.26 and 34.25 mg/100g, respectively. Fruits those were analysed after 30 days

showed higher ascorbic acid contents of 37.62 mg/100 g as compared to the fruits those were

analysed after 60 and 90 days periods where ascorbic acids contents were 35.14 and 33.88

mg/100 g in fruits respectively. The interaction effect between storage treatments and storage

periods showed that higher ascorbic acid of 38.87 mg/100 g was noted in fruits those were

stored on tree and analysed after 30 days and these were at par with fruits those were stored at

8oC and analysed after 30 and 60 days periods. While, lower ascorbic acid of 30.91 mg/100 g

was noted in fruits those were stored on tree and analysed after 90 days in fruits of Ray Ruby

cultivar.

Figure 4.32a Effects of cold storage (CS) and tree storage (TS) on ascorbic acid

contents (mg/100 g) in fruits of Ray Ruby analysed after 30, 60 and

90 days periods.


0

5

10

15

20

25

30

35

40

45

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 days = 39.34 mg/100g

72

4.2.6a Total sugar contents (%)


storage periods and their interaction of total sugar contents in fruits of Ray Ruby cultivar

(Figure 4.32a). Fruits those were stored at 8oC showed higher total sugar contents of 5.61%

as compared to the fruits those were stored at 6oC and held on tree where total sugars were

5.03 and 4.57%, respectively. Fruits those were analysed after 90 days period showed higher

total sugar contents of 5.65% than the fruits those were analysed after 60 and 30 days where

total sugars were 4.84 and 4.71% and these were statistically at par to each other,

respectively. The interactive effect between storage treatments and storage periods showed

that higher total sugar contents (6.93%) were noted in fruits those were stored at 8oC and

analysed after 90 days. While, minimum total sugar contents of 4.28% were recorded in fruits

those were stored on tree and analysed after 90 days and these were statistically at par with

fruits those were stored on tree, 6oC and 8oC and analysed after 60 and 30 days, respectively.

4.2.7a Reducing sugar contents (%)

Reducing sugar contents in fruits showed significant differences regarding the effects of

storage treatments, storage periods and their interaction in Ray Ruby cultivar (Figure 4.33a).

Maximum reducing sugar contents (3.88%) were noted in fruits those were stored at 8oC as

compared to the fruits those were stored at 6oC and held on tree where reducing sugars were

3.64 and 3.43% in fruits, respectively. Fruits those were analysed after 90 days showed

higher reducing sugar contents of 3.80% than the fruits those were analysed after 60 and 30

days and these were statistically at par with each other where reducing sugars were 3.60 and

3.53% in fruits, respectively. The interaction between storage treatments and storage periods

showed that higher reducing sugar contents (4.33%) were recorded in fruits those were stored

at 8oC and analysed after 90 days. Whereas, minimum reducing sugar contents of 3.16% were

recorded in fruits those were stored on tree and analysed after 90 days and these were at par

with fruits those were stored at 6oC and hold on tree and analysed after 30 and 60 days,

respectively.

73

Figure 4.33a Effects of cold storage (CS) and tree storage (TS) on total sugar

contents (%) in fruits of Ray Ruby analysed after 30, 60 and 90

days periods.


Figure 4.34a Effects of cold storage (CS) and tree storage (TS) on reducing


90 days periods.

Each vertical bar represents mean of three replicates ± S.E

0

1

2

3

4

5

6

7

8

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


To

tal

sug

ars

(%)

Total sugar at 0 day = 4.13%

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

8°C 6°C TS 8°C 6°C TS 8°C 6°C 6oC TS


Red

ucin

g s

ug

ars

(%)

Reducing suagr at 0 day = 3.03%

74

4.2.8a Non-reducing sugar contents (%)


significant differences on non-reducing sugars in fruits of Ray Ruby cultivar (Figure 4.34a).

Fruits those were stored at 8oC showed higher non-reducing sugars of 1.73% than the fruits

those were stored at 6oC and held on tree where non-reducing sugars were 1.38 and 1.48%

and these were statistically at par with each other. Fruits of Ray Ruby those were analysed

after 90 days period showed higher value of non-reducing sugars (1.85%) as compared to the

fruits those were analysed after 60 and 30 days where non-reducing sugars were 1.23 and

1.17% and these were at par with each other, respectively. The interactive effect between

storage treatments and storage periods showed that maximum non-reducing sugar contents of

2.60% were recorded in fruits those were stored at 8oC and analysed after 90 days. While

minimum non-reducing sugar contents (1.12%) were recorded in fruits those were stored on

tree and analysed after 90 days and there were statistically at par with fruits those were stored

on tree, 6oC and 8oC on tree and analysed after 60, 30 and 60 days, respectively.

Figure 4.35a Effects of cold storage (CS) and tree storage (TS) on non-reducing


90 days periods.


4.2.1.2a Phytochemical parameters

4.2.1.2.1a Total phenolic contents (mg GAE/100 g)

Statistically significant differences were found regarding the effects of storage treatments and

storage periods while interaction between them showed non-significant results for total

0

0.5

1

1.5

2

2.5

3

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


No

n-r

ed

ucin

g s

ug

ars

(%)

Non reducing suagr at 0 days= 1.13%

75

phenolic contents in fruits of Ray Ruby cultivar (Figure 4.36a). Fruits those were stored at

8oC showed higher total phenolic contents of 161.82 mg GAE/100 g than the fruits those

were stored at 6oC and held on tree where total phenolic contents were 150.90 and 137.36 mg

GAE/100 g in fruits, respectively. Fruits those were analysed after 30 days period attained

higher total phenolic contents (164.54 mg GAE/100 g) as compared to the fruits those were

analysed after 60 and 90 days where total phenolic contents were 150.20 and 135.35 mg

GAE/100 g in fruits, respectively.

4.2.1.2.2a Total antioxidants (% DPPH inhibition)

Effects of storage treatments and storage period showed significant differences while

interaction between them was found non-significant regarding the total antioxidants activities

in fruits of Ray Ruby cultivar (Figure 4.37a). Higher total antioxidants activities (75.16%)

were recorded in fruits those were stored at 8oC as compared to the fruits those were stored at

6oC and held on tree where total antioxidants activities were 69.07 and 54.70% in fruits,

respectively. Fruits those were analysed after 30 days showed higher antioxidants activities of

73.69% than the fruits those were analysed after 60 and 90 days periods where antioxidants

activities were 67.69 and 57.56% in fruits, respectively.

Figure 4.36a Effects of cold storage (CS) and tree storage (TS) on total phenolic

contents (mg GAE/100 g) in fruits of Ray Ruby analysed after 30,



0

20

40

60

80

100

120

140

160

180

200

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TP

C (

mg

GA

E/1

00

g)

TPC at 0 days = 161 mgGAE/100g

76


antioxidants activities (% DPPH inhibition) in fruits of Ray Ruby



4.2.1.2.3a Total flavonoids contents (mg CEQ/100 g)

Total flavonoids contents (TFC) in fruits showed statistically significant differences

regarding the effects of storage treatments, storage periods and their interaction in Ray Ruby

cultivar (Figure 4.38a). Fruits those were stored at 8oC showed higher TFC of 57.82 mg

CEQ/100 g than the fruits those were stored at 6oC and held on tree where TFC were 53.38

and 39.63 mg CEQ/100 g in fruits, respectively. Maximum TFC of 56.83 was noted in fruits

those were analysed after 30 days period as compared to fruits those were analysed after 60

and 90 days where TFC were 50.76 and 43.24 mg CEQ/100 g in fruits, respectively. The

interactive effect between storage treatments and storage periods showed that higher TFC of

61.66 mg CEQ/100 g was recorded in fruits those were stored at 8oC and analysed after 30

days and these were statistically at par with fruits those were stored at 8oC and 6oC and

analysed after 60 and 30 days, respectively. While lower TFC (27.32 mg CEQ/100 g) was

noted in fruits those were stored on tree and analysed after 90 days in in fruits of Ray Ruby

cultivar.

4.2.1.2.4a Total carotenoids (mg/100 g)

The analysed data presented in Figure 4.39a showed significant differences regarding the

effects of storage treatments, storage periods and their interaction on total carotenoids in

fruits of Ray Ruby cultivar. Higher total carotenoids of 18.42 mg/100 g were noted in fruits

those were stored at 8oC as compared to the fruits those were stored at 6oC and held on tree

0

10

20

30

40

50

60

70

80

90

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


% D

PP

H i

nh

ibit

ion

TAA at 0 day = 67.7%

77

where total carotenoids were 17.67 and 14.71 mg/100 g in fruits, respectively. Fruits those

were analysed after 30 days showed higher total carotenoids (18.81 mg/100 g) than the fruits

those were analysed after 60 and 90 days periods where total carotenoids were 16.80 and

15.20 mg/100 g in fruits, respectively. The interaction between storage treatments and storage

periods showed that maximum total carotenoids of 19.95 mg/100 g were recorded in fruits

those were stored at 8oC and analysed after 30 days. While lower total carotenoids of 11.63

mg/100 g were noted in fruits those were stored on tree and analysed after 90 days in Ray

Ruby cultivar (Figure 4.39a).


flavonoids contents (mg CEQ/100 g) in fruits of Ray Ruby



0

10

20

30

40

50

60

70

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TF

C (

mg

CE

Q/1

00

g)

TFC at 0 days 53.23mgCEQ/100g

78


carotenoids (mg/100 g) in fruits of Ray Ruby analysed after 30, 60



4.2.1.2.5a Total limonin contents (µg/mL)

Total limonin contents in fruits showed significant differences regarding the effects of storage

treatments, storage periods and their interaction in Ray Ruby cultivar (Figure 4.40a). Fruits

those were stored at 8oC showed lower amounts of total limonin contents (10.18 µg/mL) than

the fruits those were stored at 6oC and held on tree where total limonin contents were 10.90

and 14.22 µg/mL in fruits, respectively. Regarding the response of storage periods, fruits

those were analysed after 90 days showed lower total limonin contents of 11.28 µg/mL and

these were statistically at par with fruits those were analysed after 60 days period where

limonin contents were 11.58 µg/mL followed by fruits analysed after 30 days. The interaction

effect between storage treatments and storage periods showed that lower limonin contents of

8.95 µg/mL were noted in fruits those were stored at 8oC and analysed after 90 days. While,

higher limonin contents of 15.39 µg/mL were noted in fruits those were stored on tree and

analysed after 90 days period.

0

5

10

15

20

25

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


To

tal

caro

ten

oid

s (m

g/1

00 g

)

TC at 0 days = 19.21 mg/100g

79

Figure 4.40a Effects of cold storage (CS) and tree storage (TS) on total limonin

contents (µg/mL) in fruits of Ray Ruby analysed after 30, 60 and

90 days periods.


4.2.1.3a Physiological parameters

4.2.1.3.1a Chilling injury (%)

Chilling injury in fruits showed statistically significant differences regarding the effects of

storage treatments, storage periods and their interaction in Ray Ruby cultivar (Figure 4.41a).

In cold storage, fruits those were stored at 8oC showed lower chilling injury of 3.55% than

the fruits those were stored at 6oC where chilling injury was 11.44% while fruits those were

stored on tree showed no chilling injury in fruits. Fruits those were analysed after 90 days

showed higher chilling injury of 5.77% and that was statistically at par with the fruits those

were analysed after 60 days where chilling injury was 5.11% followed by fruits analysed

after 30 days with chilling injury of 4.11% in fruits of Ray Ruby. The interaction effect

showed that lower chilling injury of 2.66% in cold storage was noted in fruits those were

stored at 8oC and analysed after 30 days period and that was at par with fruits stored at 8oC

and analysed after 60 days where chilling injury was 3.66% in fruits.

4.2.1.3.2a Fruit rot (%)

Statistically significant results were found regarding the effects of storage treatments, storage

periods and their interaction on fruit rot in Ray Ruby cultivar (Figure 4.42a). Fruits those

were analysed after 90 days period showed higher fruit rottenness of 7.44% than the fruits

those were analysed after 60 and 30 days where fruits rot were 5.22 and 4.11%, respectively.

The interactive effect between storage treatments and storage periods showed that fruits

0

2

4

6

8

10

12

14

16

18

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Lim

on

in c

on

ten

ts (

µg/m

L)

TL at 0 day= 15.43µg/mL

80

stored in cold storage at 8oC and analysed after 30 and 60 days showed less fruit rot of 2.33

and 3.33%, respectively and these were statistically at par with each other. While fruits those

were held on tree and analysed after 30, 60 and 90 days showed zero present fruit rottenness.

Figure 4.41a Effects of cold storage (CS) and tree storage (TS) on chilling injury

(%) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


Figure 4.42a Effects of cold storage (CS) and tree storage (TS) on rot (%) in



0

2

4

6

8

10

12

14

16

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 days =0%

0

5

10

15

20

25

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Fru

it r

ot

(%)

Fruit rot at 0 day= 0%

81

4.2.1.3.3a Fruit weight loss (%)

Weight loss in fruits showed significant differences regarding the effects of storage

treatments and storage periods while interaction between them was found non-significant in

Ray Ruby cultivar (Figure 4.43a). Higher weight loss in fruits was noted those were stored at

8oC where weight loss was 9.66% and that was statistically at par with fruits those were

stored at 6oC where weight loss was 9.22% Fruits those were analysed after 90 days period

showed greater weight loss in fruits as compared to those analysed after 60 and 30 days

where weights losses were 6.55 and 5.44% in fruits, respectively.

4.2.1.3.4a CO2 (ml kghr-1

)


storage periods and their interaction on CO2 in fruits of Ray Ruby cultivar (Figure 4.44a).

Fruits those were stored on tree showed higher CO2 of 14.41 ml kghr-1 than the fruits those

were stored at 8oC and 6oC where CO2 was 5.37 and 4.61 ml kghr-1 in fruits, respectively.

Fruits those were analysed after 30 days period showed higher rate (9.82 ml kghr-1) of CO2 as

compared to the fruits those were analysed after 60 and 90 days where rates of CO2 were 8.33

and 6.24 ml kghr-1in fruits, respectively. The interaction effect between storage treatments

and storage periods showed that higher rate (17.44 ml kghr-1) of CO2 was recorded in fruits

those were stored on tree and analysed after 30 days. Whereas, lower rates of CO2 of 3.74 and

4.03 ml kghr-1 were noted in fruits those were stored at 6oC and 8oC and analysed after 90

period, respectively and there were statistically at par with each other.

82

Figure 4.43a Effects of cold storage (CS) and tree storage (TS) on weight loss

(%) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


Figure 4.44a Effects of cold storage (CS) and tree storage (TS) on CO2 (ml kghr-

1) in fruits of Ray Ruby analysed after 30, 60 and 90 days periods.


0

2

4

6

8

10

12

14

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Weig

ht

loss

(%

)

Weight loss at 0 day = 0 %

0

2

4

6

8

10

12

14

16

18

20

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


CO

2 (m

lkg

hr)

Co2 at 0 days 18.23 ml kg.hr-1

83

4.2.1.3.5a Ethylene (µL kghr-1

)

The rate of ethylene production showed significant differences regarding the effects of

storage treatments and storage periods while their interaction was found non-significant in

fruits of Ray Ruby cultivar (Figure 4.45a). Fruits those were stored on tree showed higher

arte of ethylene production (0.073 µL kghr-1) as compared to the fruits those were stored at

8oC and 6oC where rates of ethylene were 0.444 and 0.333 in fruits, respectively. Regarding

the response of storage periods, fruits those were analysed after 90 days showed higher rate

of ethylene production of 0.067µL kghr-1 than the fruits those were analysed after 60 and 30

days where ethylene production rates were 0.047 and 0.035 µL kghr-1 in fruits, respectively.

Figure 4.45a. Effects of cold storage (CS) and tree storage (TS) on ethylene (µL

kghr-1

) in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


0

0.02

0.04

0.06

0.08

0.1

0.12

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Eth

yle

ne (

µL

kg

hr-1

)

Ethylene at 0 day = 0.03 µL kg.hr-1

84

4.2.1.4a Organoleptic parameters

4.2.1.4.1a Color score


storage periods and their interaction on color score in fruits of Ray Ruby cultivar (Figure

4.46a). Fruits those were stored at 8oC received maximum color scores of 7.00 by the

panellists as compared to the fruits those were stored at 6oC and held on tree where color

scores were 6.22 and 2.77, respectively. Fruits those were analysed after 90 days showed

higher index of color scores (6.00) than the fruits those were analysed after 60 and 30 days

periods where color scores were 5.33 and 4.66 rated by the panellists, respectively. The

interaction effect showed that higher color score of 8.33 rated by the panellists was recorded

in fruits those were stored at 8oC and analysed after 90 days. While minimum color scores of

2.33 and 2.66 ranked by the panellists were noted in fruits those were stored on tree and

analysed after 90 and 60 days, respectively and these were at par with each other.

4.2.1.4.2a Texture score

Texture scores in fruits showed significant differences regarding the effects of storage

treatments and interaction while storage periods showed non- significant differences (Figure

4.47a). Fruits those were stored at 8oC showed higher texture score of 7.66 marked by the

panellists as compared to the fruits those were stored at 6oC and held on tree where texture

scores were 5.88 and 3.55, respectively. The interaction effect showed that higher texture

scores of 8.33 and 7.66 ranked by the panellists were recorded in fruits those were stored at

8oC and analysed after 90 and 60 days, respectively. While minimum texture score of 2.33

was noted in fruits those were stored on tree and analysed after 90 days period.

85

Figure 4.46a Effects of cold storage (CS) and tree storage (TS) on color scores in



Figure 4.47 a Effects of cold storage (CS) and tree storage (TS) on texture scores



0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Co

lor s

core

Colour score at 0 days = 2.23

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Textu

re s

co

re

Txtuere Score at 0 day = 4.02

86

4.2.1.4.3a Taste score

Effects of storage treatments and interaction showed significant differences while storage

periods did not differ significantly regarding the taste score in fruits of Ray Ruby cultivar

(Figure 4.48a). Maximum taste score of 8.00 marked by the panellists was recoded in fruits

those were stored at 8oC than the fruits those stored at 6oC and held on tree where taste scores

were 6.88 and 3.33, respectively. The interaction effect between storage treatments and

storage periods showed that higher taste score of 8.66 was noted in fruits those were stored at

8oC and analysed after 90 days. While minimum taste scores of 2.33 and 3.33 marked by the

panellists were recorded in fruits those were stored on tree and analysed after 90 and 60 days,

respectively.

4.2.1.4.4a Sourness score


storage periods while their interaction showed non-significant results on sourness in fruits of

Ray Ruby cultivar (Figure 4.49a). Fruits those were stored at 8oC showed minimum sourness

score of 3.11 marked by the panellists than the fruits those were stored at 6oC and held on

tree where sourness scores were 4.88 and 6.22, respectively. Fruits those were analysed after

90 days showed higher sourness score of 6.33 as compared to the fruits those were analysed

after 60 and 30 days where sourness scores were 4.44 and 3.44 in fruits, respectively.

Figure 4.48a Effects of cold storage (CS) and tree storage (TS) on taste scores in


Each vertical bar represents mean of three replicates ± S.

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Tast

e s

co

re

Taste at 0 days = 3.33

87

Figure 4.49a Effects of cold storage (CS) and tree storage (TS) on sourness

scores in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


4.2.1.4.5a Sweetness score

The effects of storage treatments, storage periods and their interaction showed significant

differences on sweetness score in fruits of Ray Ruby cultivar (Figure 4.50a). Fruits stored at

8oC showed higher sweetness score of 6.11 marked by the panellists than the fruits those

were stored at 6oC and held on tree where sweetness scores were 5.11 and 4.00, respectively.

Fruits those were analysed after 90 days showed maximum sweetness score of 5.55 followed

by 60 and 30 days where sweetness scores were 5.00 and 4.66, respectively. The interaction

effect between storage treatments and storage periods showed that higher sweetness score of

7.66 rated by the panellists was noted in fruits those were stored at 8oC and analysed after 90

days. While minimum sweetness score marked by the panellists was 2.66 in fruits those were

stored on tree and analysed after 90 days.

4.2.1.4.6a Overall quality score

Overall quality score showed statistically significant differences regarding the effects of

storage treatments and interaction while storage periods showed non-significant results in

fruits of Ray Ruby cultivar (Figure 4.51a). Fruits those were stored at 8oC showed higher


tree where overall quality scores were 7.33 and 3.11, respectively. The interaction effect

between storage treatments and storage periods showed that higher overall quality score of

8.66 ranked by the panellists was noted in fruits those were stored at 8oC and 6oC and

0

1

2

3

4

5

6

7

8

9

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


So

urn

ess

sco

re

Sourncess at 0 day = 4.55

88

analysed after 30, 60 and 90 days, respectively and these were statistically at par with each

other. Whereas, minimum overall quality score of 1.66 was recorded in fruits those were

stored on tree and analysed after 90 days period.

Figure 4.50a Effects of cold storage (CS) and tree storage (TS) on sweetness

scores in fruits of Ray Ruby analysed after 30, 60 and 90 days

periods.


Figure 4.51a Effects of cold storage (CS) and tree storage (TS) on overall

quality scores in fruits of Ray Ruby analysed after 30, 60 and 90

days periods.


0

1

2

3

4

5

6

7

8

9

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Sw

eetn

ess

sco

re

Sweetncess at 0 day = 4.66

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Overall

qu

ali

ty s

core

Overall quality at 0 days= 3.55

89

4.2. Experiment-1 (b) Effects of cold storage and tree storage (delayed

harvesting) relating to their quality and shelf life of

grapefruit Cv. Shamber

Results 4.2.1b

4.2.1.1b Biochemical parameters

4.2.1.1.1b pH of juice


differences regarding the pH of juice in fruits of Shamber cultivar (Figure 4.52 b). Higher pH

of 5.54 was noted in fruits those were stored at 8oC as compared to the fruits stored at 6oC

and held on tree where pH in fruits was 4.79 and 3.60, respectively. Fruits those were

analysed after 90 days showed higher pH of 5.26 than the fruits those were analysed after 60

and 30 days where pH in fruits was 4.67 and 4.00, respectively. The interaction between

storage treatments and storage periods showed higher pH of 6.97 in fruits those were stored at

8oC and analysed after 90 days. While, lower pH of 3.01 and 3.51 were noted in fruits those

were stored on tree and analysed after 90 and 60 days periods and these were statistically at

par with in fruits of Shamber cultivar.

4.2.1.1.2b Total soluble solids (oBrix)

Total soluble solids in fruits of Shamber showed statistically significant differences regarding

the effects of storage treatments, storage periods and their interaction (Figure 4.53b). Fruits

those were stored at 8oC showed higher TSS contents of 7.83 oBrix as compared to fruits

those were stored at 6oC and held on tree where TSS contents in fruits were 7.11 and 5.95

oBrix, respectively. Higher TSS of 7.53 oBrix was noted in fruits those were analysed after 90

days than the fruits those were analysed after 60 and 30 days periods where TSS contents

were 7.00 and 6.36 oBrix. The interaction effect between storage treatments and storage

periods showed that higher TSS of 9.22 oBrix was recorded in fruits those were stored at 8oC

and analysed after 90 days. Whereas, lower TSS of 5.14 oBrix was recorded in fruits those

were stored on tree and analysed after 90 days.

90

Figure 4.52b Effects of cold storage (CS) and tree storage (TS) on pH in fruits of

Shamber analysed after 30, 60 and 90 days periods.


Figure 4.53b Effects of cold storage (CS) and tree storage (TS) on TSS (oBrix) in



0

1

2

3

4

5

6

7

8

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


pH

pH at 0 day =3.33

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TS

S (

oB

rix

)

TSS at 0 day = 5.54 °Brix

91

4.2.1.1.3b Total titratable acidity (%)

The effects of storage treatments and interaction showed statistically significant differences

while storage periods showed non-significant results for total titratable acidity in fruits of

Shamber cultivar (Figure 4.54b). Lower titratable acidity of 1.40% was recorded in fruits

those were stored at 8oC than the fruits those were stored at 6oC and held on tree where

titratable acidity was 1.52 and 1.40% in fruits of Shamber. The interactive effect of storage

treatments and storage periods showed that lower titratable acidity of 1.23% was noted in

fruits those were stored at 8oC and analysed after 90 days. Meanwhile, higher titratable

acidity of 1.98% was recorded in fruits those were stored on tree and analysed after 90 days

period in Shamber cultivar.

4.2.1.1.4b TSS/acidity ratio


storage periods and their interaction on TSS/acidity ratio in fruits of Shamber cultivar (Figure

55b). Fruits those were stored at 8oC showed higher TSS/acidity ratio of 5.73 as compared to

the fruits those were stored at 6oC and held on tree where TSS/acidity was 4.77 and 3.66,

respectively. Fruits those were analysed after 90 days period attained maximum TSs/acidity

of 5.50 than the fruits those were analysed after 60 and 30 days where TSS/acidity was 4.67

and 4.09, respectively. The interaction effect between storage treatments and storage periods

showed that higher TSS/acidity of 7.48 was recorded in fruits those were stored at 8oC and

analysed after 90 days. While, minimum TSS/acidity 2.58 was noted in fruits those were

stored on tree and analysed after 90 days period.

92

Figure 4.54b Effects of cold storage (CS) and tree storage (TS) on titratable

acidity (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.


Figure 4.55b Effects of cold storage (CS) and tree storage (TS) on TSS/acidity

ratio in fruits of Shamber analysed after 30, 60 and 90 days

periods.


0

0.5

1

1.5

2

2.5

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Acid

ity (

%)

Acidity at 0 day =1.46%

0

1

2

3

4

5

6

7

8

9

8°C 6°C TS 8oC 6oC TS 8°C 6°C TS


TS

S/a

cid

ity

TSS/Acidity at 0 day = 4.05

93

4.2.1.1.5b Ascorbic acid (mg/100 g)

Ascorbic acid contents showed significant differences regarding the effects of storage

treatments, storage periods and their interaction in fruits of Shamber cultivar (Figure 4.56b).

Maximum ascorbic acid contents of 37.84 mg/100 g were noted in fruits those were stored at

8oC than the fruits those were stored at 6oC and held on tree where ascorbic acid contents

were 35.51 and 33.73 mg/100 g, respectively. Fruits those were analysed after 30 days

showed higher ascorbic acid contents of 38.10 mg/100 g as compared to the fruits those were

analysed after 60 and 90 days periods where ascorbic acids contents were 35.00 and 33.92

mg/100 g in fruits, respectively and these were at par with each other. The interaction effect

between storage treatments and storage periods showed that higher ascorbic acid of 39.21

mg/100 g was noted in fruits those were stored on tree and analysed after 30 days and that

was at par with fruits those were stored at 8oC and analysed after 30 days period. While,

lower ascorbic acid content of 29.96 mg/100 g was noted in fruits those were stored on tree

and analysed after 90 days in fruits of Shamber cultivar.

Figure 4.56b Effects of cold storage (CS) and tree storage (TS) on ascorbic acid

contents (mg/100 g) in fruits of Shamber analysed after 30, 60 and

90 days periods.


0

5

10

15

20

25

30

35

40

45

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 day = 39.3mg/100g

94

4.2.1.1.6b Total sugar contents (%)


storage periods and their interaction on total sugar contents in fruits of Shamber cultivar

(Figure 4.57 b). Fruits those were stored at 8oC showed higher total sugar contents of 6.32%

as compared to the fruits those were stored at 6oC and held on tree where total sugar contents

were 5.61 and 4.82%, respectively. Fruits those were analysed after 90 days period showed

higher total sugar contents of 6.02% than the fruits those were analysed after 60 and 30 days

where total sugars were 5.47 and 5.26% and these were statistically at par to each other,


that higher total sugar contents (7.54%) were noted in fruits those were stored at 8oC and

analysed after 90 days. While, lower total sugar contents of 4.18% were recorded in fruits

those were stored on tree and analysed after 90 days period in Shamber cultivar.

4.2.1.1.7b Reducing sugar contents (%)

Reducing sugar contents in fruits showed significant differences regarding the effects of

storage treatments, storage periods and their interaction in Shamber cultivar (Figure 4.58b).

Higher reducing sugar contents of 4.40% were noted in fruits those were stored at 8oC as

compared to the fruits those were stored at 6oC and held on tree where reducing sugar

contents were 4.02 and 3.56% in fruits, respectively. Fruits those were analysed after 90 days

showed higher reducing sugar contents of 4.12% and that was statistically at par with the

fruits those were analysed after 60 followed by 30 days where reducing sugars were 3.95 and

3.91% and these were at par to each other, respectively. The interaction between storage

treatments and storage periods showed that higher reducing sugar contents (4.93%) were

recorded in fruits those were stored at 8oC and analysed after 90 days. Whereas, lower

reducing sugar contents of 3.09% were recorded in fruits those were stored on tree and

analysed after 90 days.

95

Figure 4.57 b Effects of cold storage (CS) and tree storage (TS) on total sugar

contents (%) in fruits of Shamber analysed after 30, 60 and 90

days periods.


Figure 4.58 b Effects of cold storage (CS) and tree storage (TS) on reducing

sugar contents (%) in fruits of Shamber analysed after 30, 60 and

90 days periods.


0

1

2

3

4

5

6

7

8

9

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


To

tal

sug

ars

(%)

Total sugar at 0 day 4.33%

0

1

2

3

4

5

6

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Red

ucin

g s

ug

ars

(%)

Reducing sugar at 3.33%

96

4.2.1.1.8b Non-reducing sugar contents (%)


significant differences on non-reducing sugar contents in fruits of Shamber cultivar (Figure

4.59 b). Fruits those were stored at 8oC showed higher non-reducing sugar contents of 1.92%

than the fruits those were stored at 6oC and held on tree where non-reducing sugars were 1.59

and 1.26% in fruits, respectively. Fruits those were analysed after 90 days period showed

higher non-reducing sugar contents of 1.90% as compared to the fruits those were analysed

after 60 and 30 days where non-reducing sugars were 1.52 and 1.35% and these were

statistically at par with each other, respectively. The interaction effect between storage

treatments and storage periods showed that maximum non-reducing sugar contents of 2.61%

were recorded in fruits those were stored at 8oC and analysed after 90 days period. While

lower non-reducing sugar contents (1.08%) were recorded in fruits those were stored on tree

and analysed after 90 days and these were statistically at par with fruits those were stored at

6oC and held on tree and analysed after 30 and 60 days periods, respectively.

Figure 4.59b Effects of cold storage (CS) and tree storage (TS) on non-reducing

sugar contents (%) in fruits of Shamber analysed after 30, 60 and

90 days periods.


0

0.5

1

1.5

2

2.5

3

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


No

n-r

ed

ucin

g s

ug

ars

(%)

Non reducing suagr at 0 day 1.13%

97

4.2.1.2b Phytochemical parameters

4.2.1.2.1b Total phenolic contents (mg GAE/100 g)

Effects of storage treatments and storage periods showed statistically significant differences

while interaction between them was found non-significant regarding the total phenolic

contents in fruits of Shamber cultivar (Figure 4.60 b). Fruits those were stored at 8oC showed

higher total phenolic contents of 168.95 mg GAE/100 g than the fruits those were stored at

6oC and held on tree where total phenolic contents were 158.36 and 143.48 mg GAE/100 g in

fruits, respectively. Fruits those were analysed after 30 days period attained higher total

phenolic contents (172.04 mg GAE/100 g) as compared to the fruits those were analysed after

60 and 90 days where total phenolic contents were 157.20 and 141.56 mg GAE/100 g,

respectively in fruits of Shamber.

4.2.1.2.2b Total antioxidants (% DPPH inhibition)


storage periods while interaction between them showed non-significant results for total

antioxidants in fruits of Shamber cultivar (Figure 4.61 b). Higher total antioxidants activities

(78.95%) were recorded in fruits those were stored at 8oC as compared to the fruits those

were stored at 6oC and held on tree where total antioxidants activities were 71.65 and 58.82%

in fruits, respectively. Fruits those were analysed after 30 days showed higher antioxidants

activities of 76.40% than the fruits those were analysed after 60 and 90 days periods where

antioxidants activities were 71.06 and 61.97%, respectively.

98

Figure 4.60b Effects of cold storage (CS) and tree storage (TS) on total phenolic

contents (mg GAE/100 g) in fruits of Shamber analysed after 30,



Figure 4.61b Effects of cold storage (CS) and tree storage (TS) on total

antioxidants activities (%DPPH inhibition) in fruits of Shamber



0

50

100

150

200

250

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TP

C (

mg

GA

E/1

00

g)

TPC at 0 day = 164.1 mgGAE/100g

0

10

20

30

40

50

60

70

80

90

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


% D

PP

H i

nh

ibit

ion

TAA at 0 day = 72.23%

99

4.2.1.2.3b Total flavonoids contents (mg CEQ/100 g)

Total flavonoids contents (TFC) in fruits showed statistically significant differences

regarding the effects of storage treatments, storage periods and their interaction in Shamber

cultivar (Figure 4.62b). Fruits those were stored at 8oC showed higher TFC of 62.29 mg

CEQ/100 g than the fruits those were stored at 6oC and held on tree where TFC were 56.87

and 44.23 mg CEQ/100 g in fruits, respectively. Maximum TFC of 60.75 mg CEQ/100 g

were noted in fruits those were analysed after 30 days period as compared to fruits those were

analysed after 60 and 90 days where TFC were 54.82 and 47.82 mg CEQ/100 g in fruits,


that higher TFC of 65.74 mg CEQ/100 g were recorded in fruits those were stored at 8oC and

analysed after 30 days and these were statistically at par with fruits those were stored at 8 oC

and 6oC and analysed after 60 and 30 days, respectively. While lower TFC (32.13 mg

CEQ/100 g) were noted in fruits those were stored on tree and analysed after 90 days in fruits

of Shamber cultivar.

4.2.1.2.4b Total carotenoids (mg/100 g)

The analysed data presented in Figure 4.63b showed that significant differences were found

regarding the effects of storage treatments, storage periods and their interaction on total

carotenoids in fruits of Shamber cultivar. Higher total carotenoids of 20.90 mg/100 g were

noted in fruits those were stored at 8oC as compared to the fruits those were stored at 6oC and

held on tree where total carotenoids were 19.64 and 16.86 mg/100 g in fruits, respectively.

Fruits those were analysed after 30 days showed higher total carotenoids (21.12 mg/100 g)

than the fruits those were analysed after 60 and 90 days periods where total carotenoids were

19.12 and 17.16 mg/100 g in fruits, respectively. The interaction between storage treatments

and storage periods showed that maximum total carotenoids of 22.55 mg/100 g were recorded

in fruits those were stored at 8oC and analysed after 30 days. While lower total carotenoids of

13.81 mg/100 g were noted in fruits those were stored on tree and analysed after 90 days.

100


flavonoids contents (mg CEQ/100 g) in fruits of Shamber analysed




carotenoids contents (mg/100 g) in fruits of Shamber analysed



0

10

20

30

40

50

60

70

80

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


TF

C (

mg

CE

Q/1

00

g)

TFC at 0 days = 57.23 mgCEQ/100g

0

5

10

15

20

25

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


To

tal

caro

ten

oid

s (m

g/1

00 g

)

TC at 0 day= 20.2 mg/100g

101

4.2.1.2.5b Total limonin contents (µg/mL)

Total limonin contents in fruits showed significant differences regarding the effects of storage

treatments, storage periods and their interaction in Shamber cultivar (Figure 4.64b). Fruits

those were stored at 8oC showed lower amounts of total limonin contents (8.05 µg/mL) than

the fruits those were stored at 6oC and held on tree where total limonin contents were 8.90

and 12.01 µg/mL in fruits, respectively. Regarding the response of storage periods, fruits

those were analysed after 90 days showed lower total limonin contents of 8.99 µg/mL as

compared to the fruits those were analysed after 60 and 30 days periods where limonin

contents were 9.72 and 10.26 µg/mL, respectively. The interaction effect between storage

treatments and storage periods showed that lower limonin contents of 6.66 µg/mL were noted

in fruits those were stored at 8oC and analysed after 90 days. While, higher limonin contents

of 12.84 and 12.03 µg/mL were noted in fruits those were stored on tree and analysed after 90

and 60 days periods, respectively.

Figure 4.64b Effects of cold storage (CS) and tree storage (TS) on total limonin

contents (µg/mL) in fruits of Shamber analysed after 30, 60 and 90

days periods.


0

2

4

6

8

10

12

14

16

8°C 6°C TS 8°C 6°C TS 8oC 6°C TS


To

tal

lim

on

in c

on

ten

ts (

µg

/mL

)

TL at 0 day = 13. 32µg/mL

102

4.2.1.3b Physiological parameters

4.2.1.3.1b Chilling injury (%)

Chilling injury in fruits showed statistically significant differences regarding the effects of

storage treatments, storage periods and their interaction in Shamber cultivar (Figure 4.65b).

In cold storage, fruits those were stored at 8oC showed lower chilling injury of 3.22% than

the fruits those were stored at 6oC where chilling injury was 10.22% while fruits those were

stored on tree showed zero chilling injury. Fruits those were analysed after 90 days showed

higher chilling injury of 5.44% than the fruits those were analysed after 60 and 30 days where

chilling injury was 4.44 and 3.55%, respectively in fruits of Shamber. The interaction effect

showed that higher chilling injury of 12.33% was recorded in fruits those were stored at 6oC

and analysed after 90 days.

4.2.1.3.2b. Fruit rot (%)

Statistically significant results were found regarding the effects of storage treatments, storage

periods and their interaction on fruit rottenness in Shamber cultivar (Figure 4.66b). Fruits

those were stored on tree showed zero fruit rottenness as compared to fruits those were stored

in cold storage at 8oC and 6oC where fruit rottening were 2.88 and 12.77%, respectively.

Fruits those were analysed after 90 days period showed higher fruit rottenness of 7.00% than

the fruits those were analysed after 60 and 30 days where fruits rottenness were 4.88 and

3.77%, respectively. The interactive effect between storage treatments and storage periods

showed that fruits stored in cold storage at 8oC and analysed after 90 days showed higher

Fruit rottenness 17.33 %.

103

Figure 4.65 b Effects of cold storage (CS) and tree storage (TS) on chilling injury

(%) in fruits of Shamber analysed after 30, 60 and 90 days periods.


Figure 4.66 b. Effects of cold storage (CS) and tree storage (TS) on fruit rot (%)



-2

0

2

4

6

8

10

12

14

6°C TS 8°C 6°C TS 8°C 6°C TS

60 DAS 90 DAS

Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 day = 0 %

0

2

4

6

8

10

12

14

16

18

20

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Fru

it r

ot

(%)

Fuit rot at 0 day = 0 %

104

4.2.1.3.3b Fruit weight loss (%)

Weight loss in fruits showed significant differences regarding the effects of storage

treatments, storage periods and their interaction in Shamber cultivar (Figure 4.67b). Higher

weight loss in fruits was noted those were stored at 8oC where weight loss was 9.22% as

compared to the fruits those were stored at 6oC where weight loss was 8.44% while fruits

stored on tree showed zero weight loss. Fruits those were analysed after 90 days period

showed greater weight loss of 6.77% as compared to the fruits those were analysed after 60

and 30 days where weights losses were 5.77 and 5.11% in fruits, respectively. The interaction

effect between storage treatments and storage periods showed that higher weight losses of 10

33 and 10.00% were recorded in fruits those were stored at 6oC and 8oC and analysed after 90

days period, respectively. While fruits those were stored on tree showed zero present weight

loss analysed after 30, 60 and 90 days periods.

4.2.1.3.4b CO2 (ml kghr-1

)


storage periods and their interaction on CO2 in fruits of Shamber cultivar (Figure 4.68 b).

Fruits those were stored on tree showed higher CO2 of 13.23 ml kghr-1 than the fruits those

were stored at 8oC and 6oC where CO2 rates were 4.79 and 4.13 ml kghr-1 in fruits,

respectively. Fruits those were analysed after 30 days period showed higher rate (9.00 ml

kghr-1) of CO2 as compared to the fruits those were analysed after 60 and 90 days where rates

of CO2 were 7.43 and 5.72 ml kghr-1 in fruits, respectively. The interaction effect between

storage treatments and storage periods showed that higher rate (16.65 ml kghr -1) of CO2 was

recorded in fruits those were stored on tree and analysed after 30 days. Whereas, lower rates

of CO2 of 3.59, 3.92 and 4.07 ml kghr-1 were noted in fruits those were stored at 6oC, 8oC and

analysed after 60, 90 and 30 days periods, respectively and these were statistically at par with

each other.

105

Figure 4.67 b Effects of cold storage (CS) and tree storage (TS) on fruit

weight loss (%) in fruits of Shamber analysed after 30, 60 and 90 days

periods.


Figure 4.68 b Effects of cold storage (CS) and tree storage (TS) on CO2 (ml kghr-

1) in fruits of Shamber analysed after 30, 60 and 90 days periods.


0

2

4

6

8

10

12

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Weig

ht

loss

(%

)

weight loss at 0 day = 0 %

0

2

4

6

8

10

12

14

16

18

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


CO

2 (

ml

kg

hr

-1)

CO2 at 0 days 18.53 ml.khhr-1

106

4.2.1.3.5b Ethylene (µL kghr-1

)

The rate of ethylene production showed significant differences regarding the effects of

storage treatments and storage periods while their interaction was found non-significant in

fruits of Shamber cultivar (Figure 4. 69b). Fruits those were stored on tree showed higher arte

of ethylene production (0.081 µL kghr-1) as compared to the fruits those were stored at 8oC

and 6oC where rates of ethylene were 0.047 and 0.035 in fruits, respectively. Regarding the

response of storage periods, fruits those were analysed after 90 days showed higher rate of

ethylene production of 0.074 µL kghr-1 than the fruits those were analysed after 60 and 30

days where ethylene production rates were 0.054 and 0.035 µL kghr -1, respectively in fruits

of Shamber cultivar.

Figure 4.69b Effects of cold storage (CS) and tree storage (TS) on ethylene (µL

kghr-1

) in fruits of Shamber analysed after 30, 60 and 90 days

periods.


0

0.02

0.04

0.06

0.08

0.1

0.12

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Eth

yle

ne (

µL

kg

hr- 1

)

Ethylene at 0 day = 0.03 µL kghr-1

107

4.2.1.4b Organoleptic parameters

4.2.1.4.1b Color score


storage periods and their interaction on color score in fruits of Shamber cultivar (Figure 4.

70b). Fruits those were stored at 8oC showed maximum color score of 7.33 marked by the

panellists as compared to the fruits those were stored at 6oC and held on tree where color

scores were 6.55 and 3.22, respectively. Fruits those were analysed after 90 days showed

higher index of color score (6.44) than the fruits those were analysed after 60 and 30 days

periods where color scores were 5.66 and 5.00 rated by the panellists, respectively and these

were at par with each other. The interaction effect showed that higher color score of 8.66

rated by the panellists was recorded in fruits those were stored at 8oC and analysed after 90

days. While minimum color scores of 3.00, 3.00 and 3.66 ranked by the panellists were noted

in fruits those were stored on tree and analysed after 90, 60 and 30 days, respectively and

these were at par with each other.

4.2.1.4.2b Texture score

Texture score in fruits showed significant differences regarding the effects of storage

treatments and interaction while storage periods showed non- significant differences (Figure

71b). Fruits those were stored at 8oC showed higher texture score of 7.77 marked by the

panellists as compared to the fruits those were stored at 6oC and held on tree where texture

scores were 6.55 and 3.66, respectively. The interaction effect showed that higher texture

scores of 8.33 and 7.66 ranked by the panellists were recorded in fruits those were stored at

8oC and analysed after 90 and 60 days, respectively and these were at par with each other.

While minimum texture score of 2.00 was noted in fruits those were stored on tree and

analysed after 90 days period.

108

Figure 4.70 b Effects of cold storage (CS) and tree storage (TS) on color score in



Figure 4.71 b Effects of cold storage (CS) and tree storage (TS) on texture score



0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Co

lor s

core

Colour at 0 day= 2.55

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Textu

re s

co

re

Texture at 0 day =4.22

109

4.2.1.4.3b Taste score

Effects of storage treatments and interaction showed significant differences while storage

periods did not differ significantly regarding the taste score in fruits of Shamber cultivar

(Figure 4.72b). Maximum taste score of 8.22 marked by the panellists was recoded in fruits

those were stored at 8oC than the fruits those stored at 6oC and held on tree where taste scores

were 7.22 and 3.66, respectively. The interaction effect between storage treatments and

storage periods showed that higher taste score of 8.66, 8.33, 8.00 and 7.66 were noted in

fruits those were stored at 8oC, 6oC and 8oC and analysed after 90, 60, 90 and 30 days

periods, respectively and these were statistically at par with each other. While minimum taste

scores of 2.66 and 3.66 marked by the panellists were recorded in fruits those were stored on

tree and analysed after 90 and 60 days, respectively and these were at par with each other.

4.2.1.4.4b Sourness score


storage periods while their interaction showed non-significant results on sourness in fruits of

Ray Ruby cultivar (Figure 4.73b). Fruits those were stored at 8oC showed minimum sourness


tree where sourness scores were 5.11 and 6.11, respectively. Fruits those were analysed after

90 days showed higher sourness score of 6.66 as compared to the fruits those were analysed

after 60 and 30 days where sourness scores were 4.44 and 3.66 in fruits, respectively.

4.2.1.4.5b Sweetness score


differences on sweetness score in fruits of Shamber cultivar (Figure 4.74b). Fruits stored at

8oC showed higher sweetness score of 6.55 marked by the panellists than the fruits those

were stored at 6oC and held on tree where sweetness scores were 5.55 and 4.55, respectively.

Fruits those were analysed after 90 days showed maximum sweetness score of 6.22 followed

by fruits those were analysed after 60 and 30 days where sweetness scores were 5.44 and

5.00, respectively and these were at par with each other. The interaction effect between

storage treatments and storage periods showed that higher sweetness score of 8.33 rated by

the panellists was noted in fruits those were stored at 8oC and analysed after 90 days. While

minimum sweetness scores of 3.33 and 4.33 marked by the panellists were noted in fruits

those were stored on tree and 6oC and analysed after 90 and 30 days periods, respectively and

these were statistically at par with each other.

110

Figure 4.72 b Effects of cold storage (CS) and tree storage (TS) on taste score in



Figure 4.73b Effects of cold storage (CS) and tree storage (TS) on sourness score



0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Tast

e s

co

re

Taste at 0 day = 3.55

0

1

2

3

4

5

6

7

8

9

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


So

urn

ess

sco

re

Sourncess at 0 day 4.66

111

Figure 4.74b Effects of cold storage (CS) and tree storage (TS) on sweetness

score in fruits of Shamber analysed after 30, 60 and 90 days

periods.


4.2.1.4.6b Overall quality score

Overall quality score showed statistically significant differences regarding the effects of

storage treatments and interaction while storage periods showed non-significant results in

fruits of Shamber cultivar (Figure 4.75b). Fruits those were stored at 8oC and 6oC showed

higher overall quality scores of 8.22 and 7.55 marked by the panellists, respectively and these

were at par with each other than the fruits those were stored on tree where overall quality

score was 3.77. The interaction effect between storage treatments and storage periods showed

that higher overall quality scores of 8.66, 8.33, 8.00, 7.66 and 7.66 ranked by the panellists

were noted in fruits those were stored at 8oC and 6oC and analysed after 90, 60, 90, 30 and 90

days, respectively and these were statistically at par with each other. Whereas, minimum

overall quality scores of 2.66 and 3.66 were recorded in fruits those were stored on tree and

analysed after 90 and 60 days periods, respectively and these were at par with each other.

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Sw

eetn

ess

sco

re

Sweetncess at 0 day = 4.88

112

Figure 4.75b Effects of cold storage (CS) and tree storage (TS) on overall

quality score in fruits of Shamber analysed after 30, 60 and 90

days periods.


4.2.2 (a, b) Discussion

Results regarding biochemical parameters exhibited that fruits stored at 8ºC revealed

higher fruit juice pH, total soluble solid, total sugar, reducing sugar and reduced total

titratable acidity, non reducing sugar and Vitamin C as compared to fruits stored at 6ºC and

held on tree. The possible reasons for high sugars were the conversion of organic acid into

simple sugars was optimized at 8ºC as compared to other treatments. Similarly Baryeh et al.

(2010) reported that the increased pH, TSS, TS, RS grapefruit during storage was related with

the conversion of various organic acids into simple sugars. Moreover, TA and Vitamin C

decreased during storage but comparison among the treatments showed that higher Vitamin C

contents and TSS were noted in fruits those were stored at 8ºC. This increase was might be

due to fast conversion of acid into sugars and metabolic changes that take place in fruit and

ultimately resulted in increased vitamin C (Asrey et al., 2007). In contrast, fruit stored at 6ºC

exhibited lower Vit. C contents compared to fruit stored at 8ºC. The possible reason for less

vitamin C could be due to the slower metabolic process at 6oC and it indicate that fruits were

under stress at lower temperature. Likewise, similar trend was also observed for tree stored

fruit as these fruits also exhibited reduced Vitamin C than fruit stored at higher temperature

and lead to decreased TSS contents than the fruits stored at 8oC after 90 days of 1st analysis.

The reason was the same it is because after 1st harvesting the temperature was dropped and

fruit was physiologically matured and ripe so might be some senesces processes initiated so

after 90 days of 1st harvest a decline was noted. In contrast, fruits stored at 8oC showed higher

0

1

2

3

4

5

6

7

8

9

10

8°C 6°C TS 8°C 6°C TS 8°C 6°C TS


Overall

qu

ali

ty s

core

Overallquality at 0 day = 4.22

113

TSS and reduced TA during storage. Our results are supported by the findings of Marcilla et

al. (2006) those reported that the fruits of Valencia Late were stored in two groups at 5oC to

10oC and 15oC to 20oC for 60 days and found that fruits stored at lower temperatures were

more acidic as compared to the fruits those were stored at higher temperature ranges. They

also reported that SSC increased during the storage while regarding the temperature results

were non-significant but increasing trend with increasing temperatures was noted. Similar

results were also found in guava (Asrey et al., 2007) and in apple (Tahir et al., 2007)

although these were climacteric fruits.

Another possible reason for the increased sugar contents or TSS/TA ratio is that fruit

juice acidity was decreased in the fruits stored at 8°C that ultimately enhanced the sugar acid

ratio of grapefruit in present study. Increased TSS/TA ratio also influenced other quality

related parameters for instance taste because due to lower acidity and more sweetness

consumers perceive better taste compared to acidic fruits (Igesias and Echeverria, 2009).

Similarly, tree held fruit also showed decreased TSS/TA again possibly due to conversion of

acids into simple sugars due to the temperature stress on fruit (Echeverria and Ismail, 1990).

Result regarding different phytochemicals exhibited that fruit stored at 8ºC revealed

higher TPC TAA, TC, TFC and TLC contents as compared to fruit stored at 6 ºC and held at

tree. On the other hand fruit stored at optimized temperature (8ºC) exhibited higher

phytochemicals were possibly due to the activities of PAL enzyme that has been reported to

be involved in TPC metabolism (Dixon and Paiva, 1995). In contrast, fruit stored at 6ºC

revealed reduced TPC and this reduction was may be due to gradual enzymatic changes

during storage. However, tree stored fruit showed higher reduction in TPC contents due to

continuous changes of temperature which exhibited reduced activities of enzyme and

degradation of cell wall that ultimately reduced the TPC contents of fruit (Teiz and Zeiger,

2010). Beside, activities of some enzymes, heat changes also played important role for the

reduction of TPC contents during tree held fruit. Moreover, our results are in strong

agreement with the findings of Teiz and Zeiger (2010) who observed reduced activities of

TPC during storage. Similarly, Pennycooke et al. (2004) also found that cold storage of fruit

increased the total phenolics and antioxidant capacity in citrus. The activities of TAA, TF,

TC decreased were rapidly during storage in fruit at 6°C in contrast to 8ºC. Moreover, these

compounds were also higher in fruits those were stored at 8ºC as compared to 6ºC and tree

held fruit. These changes were possibly due to the activities of pyruvate decarboxylase and

alcohol dehydrogenase enzymes as reported previously in lime (Luthi et al., 1959).

114

The activities of TFC and TC were higher in fruits during storage at 8ºC than 6ºC and

tree held fruit possibly due to chlorophyll molecule (photoassimilate), which produced during

photosynthesis and subsequently stored in fruit (Echeverria and Ismail, 1987). On the other

hand, fruit stored at optimized temperature exhibited rapid breakdown of chlorophyll

molecule and released some hormones that improved TC and TFC contents as reported

previously by Lakenbrink et al. (2000). Higher activities of TLC in fruit during storage at 8ºC

than 6 ºC and tree held fruit may due more enzymatic changes and break down of acid

(Nagar, 1994). Similar finding was correlated with Kevers et al. (2011) and Vinson et al.

(2001) in tangeria , lemon plum. On other hand fruit held on tree showed reduction of TL

due to changes in environmental temperature that cause to break down of cell wall and their

related enzyme which decreased the contents of TLC during tree storage kevers et al. (1998).

Similar finding were reported in Valenics late reduction of different enzymes and cell wall

break down during storage on tree.

Chilling injury was the major disorder limiting the storability and marketability of

grapefruit. All of these symptoms were significantly lowered at 8ºC for up to 90 days of cold

storage. Because of the high susceptibility of grapefruit to CI during cold storage at 6°C or

lower temperature its quality had badly affected. Moreover, fruit stored at 6ºC revealed more

membrane lipids from a liquid-crystalline to a solid-gel state are induced in plant tissues,

which lead to increased membrane permeability and more leakage of ions and fruit exhibit

chilling injury symptoms on surface of fruit (Gomez-Galindo et al., 2004). Moreover, our

results also corroborate the findings of Schiffman-Nadel et al. (1975); Petracek et al. (1998)

and Schirra et al. (2000) who reported that more activities of lipid enzymes helps in ethylene

synthesis pathway (ACC synthase and ACC oxidase) of fruit as the cell wall modifying

enzymes PG and galactosidase destroyed while insoluble pectin content remained higher and

caused Cl. Fruit weight loss occurred due to changes of metabolic process and frequently loss

water in fruit during storage. Fruit stored at 8ºC revealed more physiological weight loss as

compared to 6ºC storage. Similarly (Perez and Del Rio, 2002) also reported in madrian

frequently water loss were noted in fruit those were stored at 6 ºC. Fortune madrain loss 4 %

weight during storage at 8ºC. Kinnow fruit were stored at 8 ºC Showed lower physiological

weight loss 2% (Ladaniya, 2008). Lower fruit rot symptoms were noted at 8 ºC for up to 90

days of cold storage due to suppressed of disease spores in fruit. Fruit were stored at 6 ºC

showed more disease due to lower temperature which henced the germination of spores

formation so in this regard more fruit rot was noted. Zheng et al. (2004) also reported that

rapid fruit rottening occurred in mandarins during storage at lower temperature caused to

115

increased spores formation which lead more decay after 12 days of storage. Fruit those were

stored at 6 ºC showed lower respirational changes it is because the enzyme subrate link lost

that possibly to indicated the rate respirational changes during storage were slow down due

to negative effects on ACC, ACO, PG, PME, cellulose activities (Teiz and Zeiger, 2010). On

other hand fruit those were stored at 8 ºC and tree held fruit showed higher respirational

changes due to higher temperature caused to increased activity of ACO, PG, PME, cellulose

in fruit. (Teiz and Zeiger, 1998). Lemon fruit showed lower respirational changes at 5 ºC due

slowdown of ACO, PG activity. Tahir et al. (2007) reported that during storage of citrus fruit

showed higher enzyme activities at 8ºC that caused to increase the respirational changes in

sweet oranges. Moreover, Aresy et al. (2007) also reported higher of enzyme activities

directly linked with respiration and resulted in higher metabolic rates during storage in lemon

fruit.

Fruit stored at 8ºC exhibited more sweetness and liked acidity scores throughout the

experiment as compared to fruit stored at 6ºC and tree held fruit by the panelists. This

indicated that these fruits were preferred by the panelists due to the sweetness and less

acidity. It could be due to sucrose-phosphate synthase activities and hydrolysis of water

(Rathore et al., 2007). Panelist did not marked higher scores for the fruits those were stored at

6º C and held on tree due to fewer sugars and higher acidity and it is also possible that might

be due to initiation of chilling injury in fruits at 6ºC and over ripening (senses) of tree held

fruit some internal changes affected the quality of fruit and these fruit could not stand at par

with other fruit. The previous observation also support our results as lower sugar contents

and more acid in fruit usually lead to poor taste of fruit ( Abbasi et al., 2010) Likewise,

Maulndo et al. (2001) reported that conversion of acid into sugar improves the taste of citrus.

Fruit texture is mainly attributed to cell wall integrity and stored carbohydrates such as pectin

and starch (Malundo et al., 2001). Lower scores for the fruits stored at 6 ºC were might be

due to activity of pectin enzymes (esterase and poly galacturonidase) those are mostly

involved in the breakdown of insoluble pectin into soluble pectin (Malundo et al., 2001).

Overall acceptability results exhibited that average of sensory attributes (fruit texture, taste or

flavor), evidently depicts a clear picture about the quality of grapefruit. Fruit stored at 8ºC

revealed higher scores even after 90 days storage as compared to fruit stored at 6ºC and tree

held fruit due to changes of starch reserves in fruit (Babalar et al., 2007). Likewise, Pelayo et

al. (2003) reported that fast ripening leads to changes in starch of lime fruit.

116

4.2.3 (a, b) Conclusion

Fruit those were stored at 8ºC showed higher fruit quality parameters as compared to

fruit those were stored at 6ºC and intact with tree.

The fruits stored at 8ºC analysed after 90 days storage showed minimum chilling

injuries (3.55 and 3.22%) as comported to fruits those were stored at 6ºC (11.44 and

10.22%) in Ray Ruby and Shamber, respectively. The fruits stored at 8ºC showed

higher levels of TSS (6.67 and 6.97º Brix ), ascorbic acid (38.87 and 39.21 mg/100g),

total sugar (6.93 and 7.54%), reducing sugar (4.33 and 4.93%) and non-reducing

sugar (1.85 and 1.08%) as well as total phenolic compounds (135.35 and 141.56 mg

GAE/100g), total antioxidants (57.56 and 61.97%), total cartotenoids (15.20 and13.81

mg/100g), total flavonoids contents (43.24 and 47.28 mgCEQ/100g) and total limonin

contents (10.18 and 12.84 µg/mL) 90 days after storage in Ray Ruby and shamber,

respectively.

Sweetness, sourness and general acceptances measured by sensory evaluation showed

that the fruits stored at 8 ºC were preferred by the panellist as compared to fruit stored

at 6 ºC as well as to those kept intact with the trees.

Sweetness, sourness and general acceptances measured by sensory evaluation showed

that the fruits stored at 8 ºC were preferred by the panellist as compared to fruit stored

at 6 ºC as well as to those kept intact with the trees.

117

4.3. Experiment-1 (a) Comparison of hot water and fungicide treatments

on the quality and shelf life of grapefruit cv. Ray

Ruby

Results 4.3.1a



Statistically significant differences (P≤ 0.05) were found regarding the effects of hot

water treatments + fungicides, storage periods and their interaction on pH in fruits of Ray

Ruby cultivar (Figure 4.76a). Fruits those were treated with HWD for 3 min at

65oC+TBZ for 5 min (T1) showed higher pH of 5.59 and that was statistically at par with

the fruits those were treated with HWD for 3 min at 65oC+Imazalil for 5 min (T2) where

pH values was 5.49 followed by T3, T4 and To in fruits of Ray Ruby. The fruits those

were analysed after 90 days showed higher pH of 6.31 as compared to the fruits those

were analysed after 60 and 30 days periods where pH was 5.45 and 4.46, respectively.

The interaction effect between hot water treatments + fungicides and storage periods

showed that higher pH of 6.56 was recorded in fruits those were treated with T1 (HWD 53

ºC for 3 min + TBZ for 5 min) and analysed after 90 days and these were at par with the

fruit of T2 (HWD 53 ºC 3 min + imazalil for 5 min) T3 (HWD 53 ºC for 4 min + TBZ for

5 min) and T4 (HWD 53 ºC for 4 min + imazalil for 5 min) where pH was 6.48, 6.44 and

6.41 analysed after 90 days, respectively. While lower pH of 4.40 was noted in fruits

those were untreated (To) and analysed after 30 days and these were at par with fruits

those were treated with T4, (HWD 53 ºC for 4 min + imazalil for 5 min) T3, (HWD 53

ºC for 4 min + TBZ for 5 min) T2 (HWD 53 ºC 3 min + imazalil for 5 min) and T1 (HWD

53 ºC for 3 min + TBZ for 5 min) analysed after 30 days period, respectively.

This part of study has been submitted in Scientia Horticulture 2014-2015 (Under

review) under the title and author Hot water treatments reduce chilling injury and

maintain post-harvest quality in relation to enzymatic changes during storage of

grapefruit.

Ahmed, W., A. Saeed, Mailk, A.U., Ahmed. Rashid.

118

Figure 4.76 a Effects of hot water treatments and fungicides on pH during

storage at (8ºC)

To=Control, T1=HWD for 3 min at 65oC+TBZ for 5 min,

T2=HWD for 3 min at 65oC+Imazalil for 5 min, T3=HWD for 4

min at 65oC+TBZ for 5 min, T4=HWD for 4 min at

65oC+Imazalil for 5 min (HWD = Hot water dipping, TBZ=

Thiabendazole)



Total soluble solids showed significant differences (P≤ 0.05) regarding the effects of hot

water treatments + fungicides, storage periods and their interaction in fruits of Ray Ruby

cultivar (Figure 4.77a). Fruits those were treated with HWD for 3 min at 53oC+TBZ for 5

min (T1) showed higher TSS of 6.82 oBrix as compared to all other treatments. The fruits

those were analysed after 90 days showed higher TSS of 7.57 oBrix as compared to the

fruits those were analysed after 60 and 30 days periods where TSS was 6.55 and 5.41

oBrix, respectively. The interaction effect between hot water treatments + fungicides and

storage periods showed that higher TSS of 8.08 oBrix was recorded in fruits those were

treated with T1 and analysed after 90 days followed by T2, T3 and T4 where TSS was

7.88, 7.74 and 7.73 oBrix analysed after 90 days, respectively and these were at par with

each other. While lower TSS of 5.33 oBrix was noted in fruits those were untreated (To)

and these were at par with the fruits of were T4, T3, T2 and T1 analysed after 30 days

period, respectively.

0

1

2

3

4

5

6

7

To T1 T2 T3 T4 To T1 T2 T3 T4 To T1 T2 T3 T4


pH

pH at 0 day = 4.5

119

Figure 4.77a Effects of hot water treatments and fungicides on TSS (oBrix) in

fruits of during storage at (8ºC)

To=Control, T1=HWD for 3 min at 65oC+TBZ for 5 min, T2=

HWD for 3 min at 65oC+Imazalil for 5 min, T3=HWD for 4 min

at 65oC+TBZ for 5 min, T4=HWD for 4 min at 65

oC+Imazalil for

5 min (HWD= Hot water dipping, TBZ= Thiabendazole)



The effects of hot water treatments + fungicides and storage periods showed significant

differences (P≤ 0.05) while their interaction showed non-significant results for total

titratable in the fruits of Ray Ruby cultivar (Figure 4.78a). Fruits of T1 (HWD for 3 min

at 65oC+TBZ for 5 min) showed lower level of titratable acidity of 1.47% and these were

at par with the fruits those were treated with (HWD for 3 min at 53oC+Imazalil for 5 min)

where titratable acidity was 1.50% as compared to other treatments. Whereas, higher

level of titratable acidity (1.58%) was noted in fruits those were untreated (To). The fruits

those were analysed after 90 days showed higher titratable acidity of 1.36% than the fruits

those were analysed after 60 and 30 days where titratable acidity percentage were 1.47

and 1.73% in fruits, respectively.

0

1

2

3

4

5

6

7

8

9



TS

S (

oB

rix

)

TSS at 0 day = 5.5 ºBrix

120

Figure 4.78 a Effects of hot water treatments and fungicides on total titratable

acidity (%) during storage at (8ºC)




oC+Imazalil for




The analysed data presented in Figure 4.79 a showed statistically significant differences

(P≤ 0.05) regarding the effects of hot water treatments + fungicides, storage periods and

their interaction on TSS/acidity ratio in fruits of Ray Ruby cultivar. Fruits those were

treated with HWD for 3 min at 65oC+TBZ for 5 min (T1) showed higher TSS/acidity of

4.77 while lower TSS/acidity of 3.78 was noted in untreated (To) fruits. The fruits those

were analysed after 90 days showed higher TSS/acidity of 5.57 as compared to the fruits

those were analysed after 60 and 30 days where TSS/acidity was 4.45 and 3.11,

respectively. The interaction effects between hot water treatments + fungicides and

storage periods showed that higher TSS/acidity of 6.18 was recorded in fruits those were

treated with T1 (HWD 53 ºC for 3 min + TBZ for 5 min) and analysed after 90 days

followed by the fruits those were treated with T2 (HWD 53 ºC for 3 min + imazalil for 5

min), T4 (HWD 53 ºC for 4 min + imazalil for 5 min) and T3 (HWD 53 ºC for 4min +

TBZ for 5 min) where TSS/acidity was 5.86, 5.66 and 5.54 analysed after 90 days,

respectively and these were at par with each other. Whereas, lower TSS/acidity of 3.00

was noted in fruits those were untreated (To) and analysed after 30 days and these were at

par with the fruits of T3 (HWD 53 ºC for 4 min + TBZ for 5 min) T4 (HWD 53 ºC for 4

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2



Acid

ity (

%)

TA at 0 day= 1.5%

121

min + imazalil for 5 min) and T2 (HWD 53 ºC for 3 min + imazalil for 5 min) analysed

after 30 days periods, respectively.

Figure 4.79 a Effects of hot water treatments and fungicides on TSS/acidity

ratio during storage at (8ºC)




oC+Imazalil for




Ascorbic acid contents in fruits showed significant differences (P≤ 0.05) regarding the

effects of hot water treatments + fungicides, storage periods and their interaction in fruits

of Ray Ruby cultivar (Figure 4.80a). Fruits those of T1, T2, T3 and T4 showed higher

ascorbic acid contents of 34.51, 34.50, 34.43 and 34.05 mg/100 g respectively and then

these fruit of were statistically at par with each other as compared to the fruits those were

untreated (To) where ascorbic acid was 33.56 mg/100 g in fruits. The fruits those were

analysed after 90 days showed lower ascorbic acid of 31.82 mg/100 g than the fruits those

were analysed after 60 and 30 days where ascorbic acid contents were 34.44 and 36.38

mg/100 g in fruits, respectively. The interactive effect between hot water treatments +

fungicides and storage periods showed that higher ascorbic acid contents of 36.69, 36.66,

36.62 and 36.38 mg/100 were noted in fruits T2 (HWD 53ºC for 3 min + imazalil for 5

min) T1 (HWD 53ºC for 3 min + TBZ for 5 min) T3 (HWD 53ºC for 4 min + TBZ for 5

min) and To (control fruit) and analysed after 30 days period, respectively. While lower

0

1

2

3

4

5

6

7



TS

S/a

cid

ity

TSS/acidity at 0 day= 3.5

122

ascorbic acid contents (29.66 mg/100 g) were recorded in fruits those were untreated (To)

and analysed after 90 days in fruits of Ray Ruby cultivar.

Figure 4.80 a Effects of hot water treatments and fungicides on ascorbic acid

contents (mg/100 g) during storage at (8ºC)




oC+Imazalil for



4.3.1.1.6a Total sugars (%)

The total sugar contents showed significant differences (P≤ 0.05) regarding the effects of

hot water treatments + fungicides, storage periods and their interaction in the fruits of Ray

Ruby cultivar (Figure 4.81a). Fruits those were treated with (HWD for 3 min at

53oC+TBZ for 5 min) (T1) showed higher total sugar of 5.60% as compared to the fruit of

other treatments. While lower total sugar contents of 5.09% were noted in fruits those

were untreated (To). The fruits those were analysed after 90 days showed higher total

sugars of 6.44% than the fruits those were analysed after 60 and 30 days periods where

total sugar contents were 5.44 and 4.37%, respectively. The interaction effect between hot

water treatments + fungicides and storage periods showed that higher total sugars of 6.76

and 6.64% were recorded in fruits of T1 (HWD for 3 min at 53oC+TBZ for 5 min) and T2

(HWD for 3 min at 53oC+imazalil for 5 min) and analysed after 90 days, respectively and

these were at par with each other. Whereas, lower total sugar of 4.31% was noted in fruits

0

5

10

15

20

25

30

35

40



Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 day= 36.6 (mg/100g)

123

of T4 and analysed after 30 days and these were at par with then fruit of T3, T2 and T1 and

analysed after 30 days, respectively.

4.3.1.1.7a Reducing sugars (%)


water treatments + fungicides, storage periods and their interaction on reducing sugar

contents in the fruits of Ray Ruby cultivar (Figure 4.80 a). Higher amounts of reducing

sugar contents (3.88 and 3.85%) were recorded in fruits of (HWD for 3 min at 53oC+TBZ

for 5 min) T1 and (HWD for 3 min at 53oC+imazalil for 5 min) T2 and these were at par

with each other followed by T3 and T4 while lower reducing sugar of 3.61% was noted in

(untreated fruits To). Fruits those were analysed after 90 days showed maximum reducing

sugar contents of 4.44% than the fruits those were analysed after 60 and 30 days where

reducing sugars were 3.68 and 3.19% in fruits, respectively. The interactive effect

between hot water treatments + fungicides and storage periods showed that higher

amounts of reducing sugars (4.65 and 4.62%) were noted in fruits (HWD for 3 min at

53oC+TBZ for 5 min) T1 and (HWD for 3 min at 53oC+imazalili for 5 min) T2 and

analysed after 90 days period, respectively and these were statistically at par with each

other. Whereas, lower reducing sugars of 3.12 and 3.15% were recorded in fruits of

(HWD for4 min at 53oC+ imazalili for 5 min) T4 and (HWD for 4 min at 53oC+TBZ for 5

min) T3 analysed after 30 days, respectively and these were at par with each other.

124

4.3.1.1.8a Non-reducing sugars (%)

The effects of hot water treatments + fungicides, storage periods and their interaction on

non-reducing sugar contents showed significant differences in the fruits of Ray Ruby

cultivar (Figure 4.81a). Higher amounts of non-reducing sugars of 1.71, 1.68, 1.67 and

1.48% were noted in fruits T1, T3, T4 and T2, respectively and these were statistically at

par with each other while lower non-reducing sugars of 1.48% was noted in fruits those

were untreated (To). The fruits those were analysed after 90 days showed higher non-

reducing sugars of 1.99% as compared to the fruits those were analysed after 60 and 30

days where non-reducing sugars were 1.75 and 1.17%, respectively. The interaction effect

between hot water treatments + fungicides and storage periods showed that maximum

non-reducing sugars of 2.10, 2.06, 2.05 and 2.02% were recorded in fruits of T1, T4, T3

and T2, respectively and analysed after 90 fruits days and these were at par with each

other. While lower non-reducing sugars of 1.15, 1.70, 1.80, 1.83 and 1.90% were noted in

fruits (HWD for 3 min at 53oC+ imazalili for 5 min) T2, (HWD for 3 min at 53oC+TBZ

for 5 min) T1, (untreated fruit) To, (HWD for 4 min at 53oC+TBZ for 5 min) T3 and

(HWD for 4 min at 53oC+imazalili for 5 min) T4 and analysed after 30 days storage,

respectively in fruits of Ray Ruby.

Figure 4.81a Effects of hot water treatments and fungicides on total sugar





oC+Imazalil for



0

1

2

3

4

5

6

7

8



To

tal

sug

ars

(%)

TS at 0 day= 4.6%

125

Figure 4.82 a. Effects of hot water treatments and fungicides on reducing sugar





oC+Imazalil for



Figure 4.83a. Effects of hot water treatments and fungicides on non-reducing





oC+Imazalil for



0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5



Red

ucin

g s

ug

ars

(%)

RS at 0 day = 3.7%

0

0.5

1

1.5

2

2.5



No

n-r

ed

ucin

g s

ug

ars

(%)

NRS at 0 day= 1.4%

126



The analysed data presented in Figure 4.84a showed statistically significant differences

(P≤ 0.05) regarding the effects of storage periods while hot water treatments + fungicides

and their interaction were found non-significant for total phenolic contents (TPC) in the

fruits of Ray Ruby cultivar. The fruits those were analysed after 30 days showed higher

amounts of total phenolic contents of 176.64 mg/100 g as compared to the fruits those

were analysed after 60 and 90 days where TPC were 162.65 and 145.80 mg GAE/100 g in

fruits, respectively.

4.3.1.2.2a Total antioxidants activities (%DPPH inhibition)

Statistically significant differences (P≤ 0.05) were found for storage periods while hot

water treatments + fungicides and their interaction showed non-significant results on total

antioxidants activities in fruits of Ray Ruby cultivar (Figure 4.85a). Higher antioxidants

activities of 78.40% were recorded in fruits those were analysed after 30 days than the

fruits those were analysed after 60 and 90 days where total antioxidants activities were

67.80 and 57.25%, respectively.

Figure. 4.84a Effects of hot water treatments and fungicides on total phenolic

contents (mg GAE/100 g during storage at 8oC.




oC+Imazalil for



0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)

TPC at 0 day= 174.0 mg GAE /100g

127

Figure 4.85a Effects of hot water treatments and fungicides on total

antioxidants activities (% DPPH inhibition) during storage at

8oC.




oC+Imazalil for




Total flavonoids contents showed significant differences (P≤ 0.05) regarding the effects

of storage periods while hot water treatments + fungicides and their interaction showed

non-significant results in the fruits of Ray Ruby cultivar (Figure 4.86a). The fruits those

were analysed after 30 days storage showed higher amounts of total flavonoids contents

(59.22 mg CEQ/100 g) as compared to the fruits those were analysed after 60 and 90 days

where TFC were 55.16 and 49.03 mg CEQ/100 g, respectively. Decline trend was found

with the increasing period of storage.

4.3.1.2.4a Total carotenoids contents (mg/100 g)

The effects of storage periods showed significant differences (P≤ 0.05) while hot water

treatments + fungicides and their interaction were found non-significant regarding the

total carotenoids contents in the fruits of Ray Ruby (Figure 4.87a). Fruits those were

analysed after 30 days showed higher amounts of total carotenoids contents of 19.51

mg/100 g than the fruits those were analysed after 60 and 90 days where total carotenoids

were 17.49 and 14.49 mg/100 g, respectively.

0

10

20

30

40

50

60

70

80

90

100



%D

PP

H i

nh

ibit

ion

TAA at 0 day= 78.6%

128

Figure 4.86a Effects of hot water treatments and fungicides on total flavonoids





oC+Imazalil for



Figure 4.87a Effects of hot water treatments and fungicides on total

carotenoids contents (mg/100 g) during storage at 8oC.




oC+Imazalil for



0

10

20

30

40

50

60

70



TF

C (

mg

CE

Q/1

00

g)

TFC at 0 day= 50.4 mg CEQ/100g

0

5

10

15

20

25



To

tal

caro

ten

oid

s (m

g/1

00 g

)


129


Statistically significant differences (P≤ 0.05) were found regarding the effects of storage

periods while hot water treatments + fungicides and their interaction showed non-

significant results for total limonin contents (TLC) in fruits of Ray Ruby cultivar (Figure

4.88a). Higher amounts of total limonin contents of 15.47 µg/mL were noted in fruits

those were analysed after 30 days as compared to the fruits those were analysed after 60

and 90 days where total limonin contents were 13.47 and 11.97 µg/mL in fruits,

respectively.

Figure 4.88a Effects of hot water treatments and fungicides on total limonin





oC+Imazalil for



0

2

4

6

8

10

12

14

16

18



TL

C (

µg

/mL

)

TLC at 0 day= 15.9 µg/mL

130



Chilling injury showed statistically significant differences(P≤ 0.05) regarding the effects

of hot water treatments + fungicides and storage periods while their interaction was found

non-significant in the fruits of Ray Ruby cultivar (Figure 4.89a). Higher index of chilling

injury (3.22%) was noted in fruits those were untreated (To) as compared to the fruits of

T4, T2, T3 and T1 where chilling indexes were 0.888, 0.777, 0.666 and 0.444%,

respectively and these were statistically at par with each other. The fruits those were

analysed after 90 days showed higher index (1.93%) of chilling injury than the fruits

those were analysed after 60 and 30 days where chilling injury indexes were 1.20 and

0.046%, respectively.

4.2.1.3.2a Fruit rot (%)

Statistically significant (P≤ 0.05) results were found regarding the effects of hot water

treatments + fungicides and storage periods while their interaction showed non-

significant results in the fruits of Ray Ruby cultivar (Figure 4.90a). Fruits those were

untreated (To) showed higher index of fruit rottenning of 6.55% as compared to the fruits

of T2, T4, T3 and T1 where fruit rottenning indexes were 4.55, 4.55, 4.22 and 4.11% in

fruits, respectively and these were at par with each other. The fruits those were analysed

after 90 days showed higher index of rottenning (5.80%) than the fruits those were

analysed after 60 and 30 days where rottenning indexes were 4.93 and 3.66% in fruits,

respectively.


Weight loss showed significant differences (P≤ 0.05) regarding the effects of hot water

treatments + fungicides and storage periods while interaction between them did not differ

significantly in fruits of Ray Ruby cultivar (Figure 4.91a). Fruits those were untreated

(To) showed minimum loss in weight of 8.22% than the fruits of T1, T2, T3 and T4 where

losses in weights were 10.11, 10.33, 10.77 and 11.00% respectively and the fruit of

treatments these were at par with each other. The fruits those were analysed after 90 days

showed higher loss in weight of 11.93% as compared to the fruits those were analysed

after 60 and 30 days where losses were 10.53 and 7.80% in fruits, respectively.

131

Figure 4.89a Effects of hot water treatments and fungicides on chilling injury

(%) during storage at 8oC.




oC+Imazalil for



Figure 4.90a Effects of hot water treatments and fungicides on fruit rot (%)





oC+Imazalil for



0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5



Ch

illi

ng i

nju

ry (

%)

Cl at 0 day= 0 %

0

1

2

3

4

5

6

7

8



Fru

it r

ot

(%)


132

Figure 4.91a Effects of hot water treatments and fungicides on weight loss





oC+Imazalil for



4.2.1.3.4a Heat production (Kcal metric ton/day)

Statistically significant differences were found regarding the effects of hot water

treatments + fungicides and storage periods while their interaction showed non-

significant results on heat production in fruits of Ray Ruby cultivar (Figure 4.92a).

Higher heat production of 653.00 and 648.44 Kcal metric ton/day was noted in fruits

those were treated with T3 and T4 and these were at par with each other followed by the

fruit of T1 and T2 while lower heat production of 565.00 Kcal metric ton/day, respectively

was recorded in fruits those were untreated (To). The fruits those were analysed after 30

days showed higher heat production of 657.40 Kcal metric ton/day as compared to the

fruits those were analysed after 60 and 90 days where heat productions were 623.40 and

580.20 Kcal metric ton/day, respectively.

0

2

4

6

8

10

12

14

16



Weig

ht

loss

(%

)

Weight loss at 0 day= 0 %

133

Figure 4.92a Effects of hot water treatments and fungicides on heat

production (Kcal metric ton/day) during storage at 8oC.




oC+Imazalil for






water treatments + fungicides and storage periods while interaction between them showed

non-significant results for color score in the fruits of Ray Ruby cultivar (Figure 4.93a).

Fruits those were untreated (To) received lower color scores of 5.40 marked by the

panellists as compared to the fruits of T3 and T4 where color scores were 6.22 and 6.22,

respectively and these were at par with each other. While higher color scores of 6.55 and

6.55 were marked by the panellists for the fruit of (HWD for 3 min at 53oC+TBZ for 5

min) T1 HWD for 3 min at 53oC+imazalili for 5 min) T2, respectively and these were at

par with each other. Regarding the response of storage periods, fruits those were analysed

after 90d days showed higher color score of 7.00 as compared to the fruits those were

analysed after 60 and 30 days where color scores were 6.33 and 5.40 respectively.

0

100

200

300

400

500

600

700

800



Heat

pro

du

cti

on

(K

cal

metr

ic t

on

/day)

HP at 0 day = 690.4 Kacal mertic tone /day

134


Texture score showed significant differences (P≤ 0.05) regarding the effects of storage

periods while hot water treatments + fungicides and their interaction were non

significantly (Figure 4.92a). The fruits those were analysed after 30 days showed higher

score of texture (7.06) than the fruits those were analysed after 60 and 90 days where

color scores were 6.33 and 6.06, respectively (Figure 4.94a).

Figure 4.93a Effects of hot water treatments and fungicides on color score





oC+Imazalil for



0

1

2

3

4

5

6

7

8



Co

lor s

core

Colour score at 0 day= 5.4

135

Figure 4.94a Effects of hot water treatments and fungicides on texture score





oC+Imazalil for




Effects of hot water treatments + fungicides, storage periods and interaction between

them were found statistically significant (P≤ 0.05) regarding the taste score in fruits of

Ray Ruby cultivar (Figure 4.95a). Higher taste scores of 6.00, 6.00, 5.77 and 5.77 were

marked by the panellists were noted in fruits of (HWD for 3 min at 53oC+TBZ for 5 min)

T1 (HWD for 3 min at 53oC+imazalil for 5 min) T2, (HWD for 4 min at 53oC+TBZ for 5

min) T3 and (HWD for 4 min at 53oC+imazalili for 5 min) T4 and these were at par with

each other while lower taste score of 4.55 was noted in fruits those were untreated (To).

The fruits those were analysed after 90 days showed maximum taste score of 6.80 as

compared to the fruits those were analysed after 60 and 30 days where taste scores were

5.33 and 4.73, respectively. The interaction between hot water treatments + fungicides

and storage periods showed that higher taste scores of 7.66, 7.66, 7.33 and 7.33 were

marked by the panellists for the fruits (HWD for 3 min at 53oC+TBZ for 5 min) T1,

(HWD for 3 min at 53oC+imazialil for 5 min) T2, T4 (HWD for 3 min at 53oC+TBZ for 5

min) and (HWD for 4 min at 53oC+imazalili for 5 min) T3 and analysed after 90 days

period, respectively and these were at par with each other. While lower taste score of 4.00

was noted in untreated fruits (To) analysed after 90 days and these were at par with fruits

0

1

2

3

4

5

6

7

8


30 Days 60 DAS 90 DAS

Textu

re s

co

re

Textuer score at 0 day= 6.5

136

those were treated with To, T4, T3, T2, T1 and To and analysed after 60 and 30 days,

respectively.


Statistically significant differences (P≤ 0.05)were found regarding the effects of hot water

treatments + fungicides and storage periods while interaction between them showed non-

significant differences in the fruits of Ray Ruby cultivar (Figure 4.96a). Fruits those were

treated of (HWD for 3 min at 53oC+TBZ for 5 min) T1, (HWD for 3 min at

53oC+imazalili for 5 min) T2 (HWD for 4 min at 53oC+TBZ for 5 min) T3 and (HWD

for 3 min at 53oC+imazalil for 5 min) T4 received fruit sourness scores of 6.55, 6.55,

6.22 and 6.22, respectively and the fruit these treatment were at par with each but these

were higher than then fruit of other than the fruits those were untreated (To) where

sourness scores was 5.00 in the fruits. The fruits those were analysed after 90 days

showed higher sourness score of 7.40 as compared to the fruits those were analysed after

60 and 30 days where sourness scores were 6.20 and 4.73, respectively.

Figure 4.95a Effects of hot water treatments and fungicides on taste score





oC+Imazalil for



0

1

2

3

4

5

6

7

8

9



Tast

e s

co

re

Taste score at 0 day= 4.7

137

Figure 4.96a Effects of hot water treatments and fungicides on sourness score





oC+Imazalil for




The analysed data presented in Figure 4.97a showed significant differences (P≤ 0.05)

regarding the effects of hot water treatments + fungicides and storage periods while their

interaction was found non-significant for sweetness score in the fruits of Ray Ruby

cultivar. The fruits those were untreated (To) showed minimum sweetness score of 5.33

than the fruits those were treated with T1, T2, T3 and T4 where sweetness scores were

6.66, 6.66, 6.33 and 6.33, respectively and these were at par with each other. Fruits those

were analysed after 90 days received higher sweetness score of 7.73 by the panellists as

compared to the fruits those were analysed after 60 and 30 days where sweetness scores

were 6.00 and 5.06, respectively.

0

1

2

3

4

5

6

7

8

9



So

urn

ess

sco

re

Sourncess score at 0 day= 5

138


Overall quality score showed statistically significant differences (P≤ 0.05) regarding the

effects of hot water treatments + fungicides and storage periods while interaction between

them showed non-significant results (Figure 4.98a). Maximum overall quality scores of

6.66, 6.66, 6.33 and 6.33 were marker by the panellists for the fruits those were treated

with T1, T2, T3 and T4, respectively and these were at par with each other. While

minimum overall quality score of 5.66 marked by the panellists was noted in fruits those

were untreated (To) of Ray Ruby cultivar. The fruits those were analysed after 90 days

received maximum overall quality score of 7.80 as compared to the fruits those were

analysed after 60 and 30 days where overall quality scores were 6.06 and 5.13,

respectively.

Figure 4.97a Effects of hot water treatments and fungicides on sweetness score





oC+Imazalil for



0

1

2

3

4

5

6

7

8

9

10



Sw

eetn

ess

sco

re

Sweetncess score at 0 day = 5.5

139

Figure 4.98a Effects of hot water treatments and fungicides on overall quality





oC+Imazalil for



0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Over quality score at 0 day= 5.6

140

4.3. Experiment-1 (b) Comparison of hot water and fungicide

treatments on the quality and shelf life of

grapefruit Cv. Shamber

Results 4.3.1b




treatments + fungicides, storage periods and their interaction on pH in the fruits of

Shamber cultivar (Figure 4.99b). Fruits those were treated with HWD for 3 min at

53oC+TBZ for 5 min (T1) attained higher pH of 5.77 and that was statistically at par with

the fruits those were treated with T2 (HWD for 3 min at 53oC+Imazalil for 5 min) T2

where pH was 5.68 followed by the fruit of (HWD for 4 min at 53oC+TBZ for 5 min) T3,

(HWD for 4 min at 53oC+Imazalil for 5 min) T4 and To in fruits of Shamber. The fruits

those were analysed after 90 days showed higher pH of 6.50 as compared to the fruits

those were analysed after 60 and 30 days periods where pH was 5.61 and 4.61,

respectively. The interaction effect between hot water treatments + fungicides and storage

periods showed that higher pH of 6.83 and 6.73 was recorded in fruits of (HWD for 3 min

at 53oC+TBZ for 5 min) T1 and (HWD for 3 min at 53oC+Imazalil for 5 min) T2 analysed

after 90 days, respectively. While lower pH values 4.55, 4.60, 4.62, 4.62 and 4.68 were

noted in fruits of T4, T3, T2, To and T1 and analysed after 30 days storage, respectively

and these fruits were at par with each other.

141

Figure 4.99 b Effects of hot water treatments and fungicides on pH during

storage at 8oC.




oC+Imazalil for




Total soluble solids showed significant differences (P≤0.05) regarding the effects of hot

water treatments + fungicides, storage periods and their interaction in fruits of Shamber

cultivar (Figure 4.100b). Fruits of (HWD for 3 min at 53oC+TBZ for 5 min) T1 and

(HWD for 3 min at 53oC+Imazalil for 5 min) T2 showed higher TSS of 6.98 and 6.92

oBrix and these were statistically at par with each other. The fruits those were analysed

after 90 days showed higher TSS of 7.86 oBrix as compared to the fruits those were

analysed after 60 and 30 days storage where TSS values were 6.74 and 5.54 oBrix,


periods showed that higher TSS of 8.26 oBrix was recorded in fruits of (HWD for 3 min

at 53oC+TBZ for 5 min) T1 and analysed after 90 days and these were at par with the

fruits those were treated with (HWD for 3 min at 53oC+Imazalil for 5 min) T2 and (HWD

for 4 min at 53oC+Imazalil for 5 min) T3. While lower TSS of 5.49 oBrix was noted in

fruits those were untreated (To) and these were at par with the fruits of T4, T3, T2 and T1

and analysed after 30 days period, respectively.

0

1

2

3

4

5

6

7

8



pH

pH at 0 day= 3.9

142

Figure 4.100b Effects of hot water treatments and fungicides on TSS (oBrix)





oC+Imazalil for





differences (P≤0.05) while their interaction showed non-significant results for total

titratable acidity in the fruits of Shamber cultivar (Figure 4.101b). Fruits of (HWD for 3

min at 53oC+TBZ for 5 min) T1 showed lower level of titratable acidity of 1.40% and

these were at par with the fruits those were treated with (HWD for 3 min at

53oC+Imazalil for 5 min) T2 and (HWD for 4 min at 53oC+Imazalil for 5 min)T3 where

titratable acidity was 1.42 and 1.45% as compared to other treatments. Whereas, higher

level of titratable acidity (1.51%) was noted in fruits those were untreated (To). The fruits

those were analysed after 90 days showed higher titratable acidity of 1.25% than the fruits

those were analysed after 60 and 30 days storage where titratable acidity values 1.43 and

1.66% in fruits, respectively.


The analysed data presented in Figure 4.102b showed statistically significant differences

(P≤0.05) regarding the effects of hot water treatments + fungicides, storage periods and

their interaction on TSS/acidity ratio in fruits of Shamber cultivar (Figure 4.100b). Fruits

of (HWD for 3 min at 53oC +TBZ for 5 min) T1 and (HWD for 3 min at 53oC+Imazalil

0

1

2

3

4

5

6

7

8

9



TS

S (

oB

rix

)

TSS at 0 day= 5.8 ºBrix

143

for 5 min) T2 showed higher TSS/acidity of 5.16 and 5.03, respectively and these were at

par with each other while lower TSS/acidity of 4.04 was noted in untreated (To) fruits.

The fruits those were analysed after 90 days showed higher TSS/acidity of 6.30 as

compared to the fruits those were analysed after 60 and 30 days where TSS/acidity values

were 4.71 and 3.33, respectively. The interaction effect between hot water treatments +

fungicides and storage periods showed that higher TSS/acidity of 6.97 and 6.81 were

recorded in fruits of (HWD for 3 min at 53oC+TBZ for 5 min) T1 and (HWD for 3 min at

53oC+Imazalil for 5 min) T2 analysed after 90 days, respectively and these were at par

with each other. Whereas, lower TSS/acidity of 3.22 was noted in fruits those were

untreated (To) analysed after 30 days and these were at par with the fruits those were

treated with (HWD for 4 min at 53oC+Imazalil for 5 min) T4, HWD for 4 min at

53oC+TBZ for 5 min) T3, (HWD for 3 min at 53oC+Imazalil for 5 min)T2 and (HWD for

3 min at 53oC+TBZ for 5 min)T1 analysed after 30 days period, respectively.

Figure 4.101b Effects of hot water treatments and fungicides on acidity (%)





oC+Imazalil for



0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2



Acid

ity (

%)

TA at 0 day= 1.5 %

144

Figure 4.102b Effects of hot water treatments and fungicides on TSS/acidity





oC+Imazalil for




Ascorbic acid contents showed significant differences (P≤0.05) regarding the effects of

hot water treatments + fungicides, storage periods and their interaction in fruits of

Shamber cultivar (Figure 4.103b). Fruits those were untreated showed lower ascorbic acid

contents of 34.57 mg/100 g than the fruits of (HWD for 3 min at 53oC+TBZ for 5 min)

T1, (HWD for 3 min at 53oC+imazalil for 5 min)T2, (HWD for 4 min at 53oC+TBZ for 5

min)T3 and (HWD for 4min at 53oC+imazalil for 5 min)T4 where ascorbic acid contents

were 36.01, 35.98, 35.94 and 35.91 mg/100 g, respectively and these were statistically at

par with each. The fruits those were analysed after 90 days showed lower ascorbic acid of

32.87 mg/100 g as compared to the fruits those were analysed after 60 and 30 days

storage where ascorbic acid contents were 36.06 and 38.12 mg/100 g in fruits,


showed that higher ascorbic acid contents of 38.21 were noted in fruits of T1 and analysed

after 30 days and these were at par with the fruits of T2, T3, T4 and To analysed after 30

days, respectively. While lower ascorbic acid contents of (30.26 mg/100 g) was recorded

in fruits those were untreated (To) and analysed after 90 days.

0

1

2

3

4

5

6

7

8



TS

S/a

cid

ity

TSS/acidity at 0 day = 2.91

145

Figure 4.103b Effects of hot water treatments and fungicides on ascorbic acid





oC+Imazalil for



4.3.1.1.6b Total sugars (%)

The total sugar contents showed significant differences (P≤ 0.05) regarding the effects of

hot water treatments + fungicides, storage periods and their interaction in fruits of

Shamber cultivar (Figure 4.104b). Fruits of (HWD for 3 min at 53oC+TBZ for 5 min) T1

and (HWD for 3 min at 53oC+imazalili for 5 min) T2 showed higher total sugar contents

of 6.00 and 5.96% as compared to the fruit of other treatments and lower total sugar

contents (5.42%) were noted in fruits those were untreated (To). The fruits those were

analysed after 90 days showed higher total sugars contents of 6.82% than the fruits those

were analysed after 60 and 30 days periods where total sugar contents were 5.89 and

4.76%, respectively. The interaction effect between hot water treatments + fungicides and

storage periods showed that higher total sugars contents of 7.10, 7.07, 7.00 and 6.98%

were noted in fruits of (HWD for 3 min at 53oC+TBZ for 5 min) T1, (HWD for 3 min at

53oC+imazalili for 5 min)T2, (HWD for 4 min at 53oC+TBZ for 5 min)T3 and (HWD for

4 min at 53oC+imazalil for 5 min)T4 and analysed after 90 days, respectively and these

were at par with each other. Whereas, lower total sugar contents of 4.68% were recorded

in fruits those were untreated (To) and analysed after 30 days and these were at par with

the fruit of T4, T3, T2 and T1 analysed after 30 days, respectively.

0

5

10

15

20

25

30

35

40

45



Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 day=38.34 mg/100 g

146

4.3.1.1.7b Reducing sugars (%)


water treatments + fungicides, storage periods and their interaction on reducing sugar

contents in fruits of Shamber cultivar (Figure 4.105b). Higher amounts of reducing sugar

contents (4.21 and 4.17%) were recorded in fruits of and (HWD for 3 min at 53oC+TBZ

for 5 min) T1 (HWD for 3 min at 53oC+imazalil for 5 min)T2 and these were at par with

each other and lower reducing sugar contents of 3.85% were noted in fruits those were

untreated (To). Fruits those were analysed after 90 days showed higher reducing sugar

contents of 4.76% than the fruits those were analysed after 60 and 30 days where

reducing sugars were 4.04 and 3.48% in fruits, respectively. The interaction effect

between hot water treatments + fungicides and storage periods showed that higher

amounts of reducing sugars (4.94, 4.91, 4.89 and 4.86%) were noted in fruits of and

(HWD for3 min at 53oC+TBZ for 5 min)T1, and (HWD for 3 min at 53oC+imazalil for 5

min) T2 and (HWD for 4 min at 53oC+TBZ for 5 min) T3 and and (HWD for 4 min at

53oC+imazalil for 5 min)T4 and analysed after 90 days storage respectively and these

were statistically at par with each other. Whereas, lower reducing sugar contents of 3.41%

were recorded in fruits those were untreated (To) and analysed after 30 days and these

were at par with the fruit of T4, T3 and T2 analysed after 30 days, respectively.

Figure 4.104b Effects of hot water treatments and fungicides on total sugar




0

1

2

3

4

5

6

7

8



To

tal

sug

ars

(%)

TS at 0 day= 4.3%

147


oC+Imazalil for



Figure 4.105 b Effects of hot water treatments and fungicides on reducing sugar





oC+Imazalil for



4.3.1.1.8b Non-reducing sugars (%)


differences (P≤ 0.05) while their interaction was found non-significant regarding the

non-reducing sugar contents in fruits of Shamber cultivar (Figure 4.106b). Higher

amounts of non-reducing sugars (1.79, 1.78, 1.76 and 1.75%) were noted in fruits of T1,

T2, T4 and T3, respectively and fruit of that treatments were statistically at par with each

other while lower non-reducing sugars of 1.56% were noted in fruits those were untreated

(To). The fruits those were analysed after 90 days showed higher non-reducing sugars of

2.06% as compared to the fruits those were analysed after 60 and 30 days where non-

reducing sugars were 1.85 and 1.28%, respectively. The interaction effect between hot

water treatments + fungicides and storage periods showed that maximum non-reducing

sugars contents of 2.16, 2.15, 2.11 and 2.10% were recorded in fruits of T2, T1, T4 and

T3 and analysed after 90 days, respectively and fruit of hot values these were at par with

each other. While lower non-reducing sugar contents of 1.26% were noted in untreated

0

1

2

3

4

5

6



Red

ucin

g s

ug

ars

(%)

RS at 0 day= 3.6 %

148

fruits (To) and these were at par with the fruit of T2, T1, T3 and T4 and analysed after 30

days period, respectively.

Figure 4.106b Effects of hot water treatments and fungicides on non-reducing





oC+Imazalil for






(P≤ 0.05) regarding the effects of storage periods while hot water treatments + fungicides

and their interaction were found non-significant for total phenolic contents (TPC) in fruits

of Shamber cultivar. The fruits those were analysed after 30 days showed higher amounts

of total phenolic contents of 181.11 mg/100 g as compared to the fruits those were

analysed after 60 and 90 days where TPC were 166.85 and 149.90 mg GAE/100 g in

fruits, respectively.

0

0.5

1

1.5

2

2.5



No

n-r

ed

ucin

g s

ug

ars

(%)

NRS at 0 day= 1.3%

149

Figure 4.107b Effects of hot water treatments and fungicides on total phenolic

contents (mg GAE/100 g) during storage at 8oC.




oC+Imazalil for



4.3.1.2.2b Total antioxidants activities (%DPPH inhibition)

Statistically significant differences (P≤ 0.05) were found for storage periods while hot

water treatments + fungicides and their interaction showed non-significant results on total

antioxidants activities in fruits of Shamber cultivar (Figure 4.108 b). Higher antioxidants

activities of 81.46% were recorded in fruits those were analysed after 30 days than the

fruits those were analysed after 60 and 90 days where total antioxidants activities were


0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)

TPC at 0 day= 188.23 mgGAE /100g

150

Figure 4.108b Effects of hot water treatments and fungicides on total

antioxidants activities (%DPPH inhibition during storage at 8oC.




oC+Imazalil for




Total flavonoids contents showed significant differences (P≤ 0.05) regarding the effects

of storage periods while hot water treatments + fungicides and their interaction showed

non-significant results in the fruits of Shamber cultivar (Figure 4.109b). The fruits those

were analysed after 30 days period showed higher amounts of total flavonoids contents

(62.08 mg CEQ/100 g) as compared to the fruits those were analysed after 60 and 90 days

where TFC were 58.05 and 51.98 mg CEQ/100 g, respectively.

4.3.1.2.4b Total carotenoids contents (mg/100 g)

The effects of storage periods showed significant differences (P≤ 0.05) while hot water

treatments + fungicides and their interaction were found non-significant regarding the

total carotenoids contents in fruits of Shamber cultivar (Figure 4.110b). Fruits those were

analysed after 30 days showed higher amounts of total carotenoids contents of 21.42

mg/100 g than the fruits those were analysed after 60 and 90 days where total carotenoids

contents were 19.31 and 16.36 mg/100 g, respectively.

0

10

20

30

40

50

60

70

80

90



%D

PP

H i

nh

ibit

ion

TAA at 0 day= 81.78%

151

Figure 4.109b Effects of hot water treatments and fungicides on total flavonoids





oC+Imazalil for



Figure 4.110b Effects of hot water treatments and fungicides on total

carotenoids contents (mg/100 g) during storage 8oC.




oC+Imazalil for



0

10

20

30

40

50

60

70



TF

C (

mg

CE

Q/1

00

g)

TFC at 0 day= 62.79 mg CEQ/ 100g

0

5

10

15

20

25



To

tal

caro

ten

oid

s (m

g/1

00 g

0


152


Statistically significant differences (P≤ 0.05) were found regarding the effects of storage

periods while hot water treatments + fungicides and their interaction showed non-

significant results for total limonin contents (TLC) in fruits of Shamber cultivar (Figure

4.111b). Higher amounts of total limonin contents of 12.63 µg/mL were noted in fruits

those were analysed after 30 days as compared to the fruits those were analysed after 60

and 90 days where total limonin contents were 12.38 and 10.99 µg/mL in fruits,

respectively.

Figure 4.111b Effects of hot water treatments and fungicides on total limonin




at 65oC+TBZ for 5 min, T4= HWD for 4 min at 65

oC+Imazalil

for 5 min (HWD= Hot water dipping, TBZ= Thiabendazole)






significant results on chilling injury in fruits of Shamber cultivar (Figure 4.112b). Higher

index for chilling injury (2.88%) was noted in fruits those were untreated (To) as

compared to the fruits T4, T3, T2 and T1 where chilling indexes were 0.777, 0.666, 0.555

and 0.444%, respectively and these were statistically at par with each other. The fruits

0

2

4

6

8

10

12

14

16



TL

C (

µg

/mL

)


153

those were analysed after 90 days showed higher index of chilling injury (1.73%) than the

fruits those were analysed after 60 and 30 days periods where chilling injury indexes were


Figure 4.112 b Effects of hot water treatments and fungicides on chilling injury

(%) during storage at 8oC.




oC+Imazalil for



4.2.1.3.2b Fruit rot (%)


differences while their interaction was found non-significant regarding the rottening in

fruits of Shamber cultivar (Figure 4.113b). Fruits those were untreated (To) showed

higher index of fruit rottenning (6.11%) as compared to the fruits of (HWD for 4 min at

53oC+TBZ for 5 min) T3, (HWD for 4 min at 53oC+imazalil for 5 min)T4, (HWD for3

min at 53oC+imazalil for 5 min) T2 and (HWD for3 min at 53oC+TBZ for 5 min) T1

where rottenning indexes were 4.44, 4.44, 4.11 and 3.88% in fruits respectively and then

fruit of these treatment were at par with each other. The fruits those were analysed after

90 days showed higher index of rottenning (5.73%) than the fruits those were analysed

after 60 and 30 days where rottenning indexes were 4.80 and 3.26% in fruits,

respectively.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5



Ch

illi

ng i

nju

ry (

%)

Cl at 0 day= 0 %

154

Figure 4.113 b Effects of hot water treatments and fungicides on rottenning (%)





oC+Imazalil for




Weight loss in fruits showed significant differences regarding the effects of hot water

treatments + fungicides and storage periods while interaction between them did not differ

significantly in fruits of Shamber cultivar (Figure 4.114b). The fruits those were untreated

(To) showed minimum loss in weight of 8.11% than the fruits of T1, T2, T3 and T4 where

losses in weights were 9.66, 10.00, 10.44 and 10.55% in fruits, respectively and the fruit

of these treatment were at par with each other. The fruits those were analysed after 90

days showed higher loss in weight (11.66%) as compared to the fruits those were

analysed after 60 and 30 days where losses in weights were 10.06 and 7.53%,

respectively in fruits of Shamber cultivar.

0

1

2

3

4

5

6

7

8



Ro

tten

nin

g (

%)

Fruit rot at 0 day= 0 %

155

Figure 4.114 b Effects of hot water treatments and fungicides on weight loss (%)





oC+Imazalil for



4.2.1.3.4b Heat production (Kcal metric ton/day)



non-significant results for heat production in fruits of Shamber cultivar (Figure 4.115b).

The fruits of T3 and T4 showed higher heat production of 641.00 and 636.44 Kcal metric

ton/day, respectively and fruit these treatment were at par with each other. While lower

heat production of 522.11 Kcal metric ton/day was recorded in untreated fruits (To) of

Shamber cultivar. The fruits those were analysed after 30 days showed maximum heat

production values were of 644.20 than the fruits those were analysed after 60 and 90 days

where heat production was 610.47 and 568.33 Kcal metric ton/day, respectively.

0

2

4

6

8

10

12

14



Weig

ht

loss

(%

)

Weight loss at 0 day= 0 %

156

Figure 4.115 b Effects of hot water treatments and fungicides on heat

production (Kcal metric ton/day) during storage at 8oC.




oC+Imazalil for





Statistically significant differences (P≤0.05) were found regarding the effects of hot water


significant results for color score in fruits of Shamber cultivar (Figure 4.116b). Fruits

those were untreated (To) received minimum liked color score of 5.88 by the panellists as

compared to the fruits of T3, T4, T2 and T1 where color scores were 6.66 and 6.66, 7.11

and 7.11, respectively and the fruit of these treatments were at par with each other.

Regarding the response of storage periods, fruits those were analysed after 90 days

showed higher color score of 7.73 as compared to the fruits those were analysed after 60

and 30 days where color scores were 6.00 and 5.73 rated by the panellists, respectively.


The analysed date presented in Figure 4.117b showed significant (P≤0.05) results for

storage periods while hot water treatments + fungicides and interaction between them

were found non-significant regarding the texture scores in fruits of Shamber cultivar

(Figure 4.115b). The fruits those were analysed after 30 days showed higher score of

0

100

200

300

400

500

600

700

800



He

at

pro

du

cti

on

(K

cal

me

tric

to

n/d

ay)

HP at 0 day= 560 Kcal mertic tone /day

157

texture (7.60) than the fruits those were analysed after 60 and 90 days where color scores

were 6.46 and 6.33, respectively and these were at par with each other.

Figure 4.116 b Effects of hot water treatments and fungicides on color score in





oC+Imazalil for



Figure 4.117 b Effects of hot water treatments and fungicides on texture score





oC+Imazalil for



0

1

2

3

4

5

6

7

8

9

10



Co

lor s

core

Colour score at 0 day= 4.33

0

1

2

3

4

5

6

7

8

9



Textu

re s

co

re

Textuer score at 0 day= 6.5

158


Effects of hot water treatments + fungicides, storage periods and interaction between

them were found statistically significant (P≤0.05) regarding the taste scores in fruits of

Shamber cultivar (Figure 4.118b). Maximum taste scores of 6.55, 6.55, 6.11 and 6.11

were marked by the panellists for the fruits T1, T2, T3 and T4 and fruit of these treatments

were at par with each other while lower taste score of 4.77 was noted in fruits those were

untreated (To). The interaction effect hot water treatments + fungicides and storage

periods showed that higher taste scores of 8.33, 8.33, 7.66 and 7.66 were marked by the

panellists for the in fruits of T1, T2, T3 and T4 and analysed after 90 days period,

respectively and fruit of these treatment were at par with each other. While lower taste

score of 4.66 was noted in untreated (To) fruits analysed after 90 days and these were at

par with fruits of T4, T3, To, To, T1.


Statistically significant differences (P≤0.05) were found regarding the effects of hot


non-significant results on sourness scores in fruits of Shamber cultivar (Figure 4.119b).

Fruits of T1, T2, T3 and T4 attained higher liked sourness of scores of 7.00, 6.88, 6.55 and

6.55, respectively and fruit of these treatments were at par with each other than the fruits

those were untreated (To) where sourness scores were 5.33 in fruits. The fruits those were

analysed after 90 days showed higher sourness score of 7.80 as compared to the fruits

those were analysed after 60 and 30 days where sourness scores were 6.53 and 5.06,

respectively.


The analysed data presented in Figure 4.2.1.4.5b showed significant differences (P≤0.05)

regarding the effects of hot water treatments + fungicides and storage periods while their

interaction between them was found non-significant for sweetness scores in fruits of

Shamber cultivar (Figure 4.120b). The fruits those were untreated (To) showed minimum

sweetness scores of 5.66 than the fruits of (HWD for 3 min at 53oC+TBZ for 5 min) T1,

(HWD for 3min at 53oC+imazalil for 5 min) T2, (HWD for 4 min at 53oC+TBZ for 5

min) T3 and (HWD for 4 min at 53oC+imazalil for 5 min) T4 where sweetness scores

were 7.11, 7.00, 6.66 and 6.55, respectively and fruit of these were treatments at par

with each other. Fruits those were analysed after 90 days received higher sweetness score

of 8.00 by the panellists as compared to the fruits those were analysed after 60 and 30

days where sweetness scores were 6.40 and 5.40, respectively.

159

Figure 4.118 b Effects of hot water treatments and fungicides on taste score





oC+Imazalil for



Figure 4.119 b Effects of hot water treatments and fungicides on sourness score





oC+Imazalil for



0

1

2

3

4

5

6

7

8

9

10



Tast

e s

co

re


0

1

2

3

4

5

6

7

8

9

10



So

urn

ess

sco

re

Sourncess score at 0 day= 4.3

160

Figure 4.120b Effects of hot water treatments and fungicides on sweetness score





oC+Imazalil for




Overall quality scores showed statistically significant differences (P≤0.05) regarding the

effects of hot water treatments + fungicides and storage periods while interaction between

them showed non-significant results in fruits of Shamber cultivar (Figure 4.121b).

Maximum overall quality scores of 7.11, 6.88, 6.66 and 6.66 were marked by the

panellists for the fruits those were treated with (HWD for 3 min at 53oC+TBZ for 5 min)

T1, (HWD for 3 min at 53oC+imazalil for 5 min) T2, (HWD for 4 min at 53oC+TBZ for 5

min) T3 and (HWD for 4 min at 53oC+imazalil for 5 min) T4, respectively and these were

at par with each other. While minimum overall quality scores of 5.88 were marked by the

panellists for the un treated (To) fruits. The fruits those were analysed after 90 days

showed maximum overall quality scores of 8.00 as compared to the fruits those were

analysed after 60 and 30 days where overall quality scores were 6.46 and 5.46,

respectively.

0

1

2

3

4

5

6

7

8

9

10



Sw

eetn

ess

sco

re

Sweetncess score at 0 day= 4.5

161

Figure 4.121 b Effects of hot water treatments and fungicides on overall during

storage at 8oC.




oC+Imazalil for




The precise impact of Hot Water Dipping before storage on physiochemical

characteristics of grapefruit, chilling injury and fruit rot% of grapefruit during storage

were recorded. Hot water treatments and storage period showed that pH increased and

acidity decreased in fruit juice those were treated HWD for 3 min + TBZ as compared to

fruit those were treated for long period and untreated fruit. This increased pH in these

fruits during storage periods is might be due to number of reasons; firstly, the alteration of

biochemical condition of fruit due to treatments secondly, due to lower rate of respiration

and metabolic activity. Similar results were also reported by Zhou et al. (2002) who

observed that hot water treatments increased the pH values and decreased TA during

storage in lemon fruit. Fruit treated with HWD for 3 min +TBZ and stored for long period

significant decreased titratable acidity which was may be due to decrease in citric acid

and increases in soluble solids content. Similar results were also reported in apple by

Malakou and Nanos, (2005); Ozdemir and dundar, (2006) those found that TSS increased

and acidity reduced with increased storage period. Similar results were also reported by

the scientists where they found increased pH and reduced acidity by hot water treatment

in peaches and nectarines (Zhou et al., 2002; Malakou and Nanos, 2005), mandarins

0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Over allquality score at 0 day= 4.5

162

(Schirra and D. Hallewin, 1997), Strawberries (Klein and Liurie, 1990) and in oranges

(Ozdemir and dundar, 2006) during storage. .

Higher values of TSS and sugar (TS, RS, NRS) in fruit those were treated with

HWD for 3 min + TBZ indicated that accumulation of sugar related process completed

successfully in these fruit as compared to other fruits. The changes in TSS are directly

correlated with hydrolytic changes in the starch concentration during the storage period.

These changes result in the conversion of starch to sugar, which is an important index of

ripening process (Kays, 1997). Many different solutes are accumulated in vacuoles of

cells as the fruit ripens. Fruit those were treated with hot water for 3 min + TBZ showed

increased in reducing sugars with increasing storage duration. These sugars are then

converted to monosaccharide sugars (reducing sugars) with the period of time and used

for respiration (Lurie and Klein, 2006). Fruit those were treated with HWT for 3 min +

TBZ increased TSS/acidity ratio due to increased sugars decreased in acidity during the

storage. Fruit those were treated with HWD for 3 min + TBZ increased TSS/acid ratio

due to increased sugars decreased in acidity during the storage. Dhillon et al. (1997) who

stated that an increase in TSS/Acid when grapefruit and mandarin were stored at lower

temperature. Similar results were found by Jawanda et al. (1973) and singh,(1993) on

mandarin and sweet orange.

Statistically results regarding to the phytochemicals showed no significant

differences between hot treatment, storage period total phenols and antioxidant activity,

TC, TF and TL while the amounts of these phytochemicals reduced with the increased

storage period. Fruit treated with HWD for 3 min at 53ºC showed lower Cl and fruit rot%

(FR) as compared to fruit those were treated with higher exposure time for 4 min at 53 ºC

and untreated fruit. Lower Cl values were recorded in fruits those were treated with hot

water and analyzed after 30 days storage as compared to same fruit those were analyzed

after 60, 90 days. The present finding are supported by the findings of Rodov et al.

(1995) they reported that hot water treatment released some protein which covered cell

wall layer and protected the fruits against Cl during storage. Gonzalez-Aguilar et al.

(1997) found that hot water treatment developed a peptide layer over the fruit which

reduced the Cl during storage. Similar results were also reported by Ali et al. (2000)

where they found that heating of ‘Fortune’ mandarin considerably decreased the

symptoms of CI during storage.

Lower fruit rot symptoms were noted at 8ºC for up to 90 days of cold storage due

to suppressed of disease spores in fruit as compared to fruit those were stored at 6ºC

163

showed more disease due to lower temperature which henced the germination of spores

formation in cell wall so in this regard more fruit rot was noted. Zhang et al. (2004) also

reported that rapid fruit rottening occurred in mandarins during storage at lower

temperature caused to increased spores formation which lead more decay after 12 days of

storage. Fisk et al. (2008) who reported that lower temperature increased spore formation

in lemon fruit. Less fruit rot% in fruits those were treated with HWT for 3min + TBZ

showed that this treatment is might be more affective to induce a defense mechanism

against pathogen in fruits. It is because hot water treatment develops a defense

mechanism in the outer layer of epicarp that inhibits the pathogen spread in fruits during

storage (Dettori et al., 1996; Ben-Yehoshua et al., 2000; D’hallewin et al., 1997). The

fruits treated with HWD for 4 min at 53ºC showed higher fruit weight loss as compared to

fruit those were treated with lower exposure time for 3 min at 53ºC and untreated fruits. It

is might be possible that higher exposure time for HWT removed or damaged the

epicuticular waxes those were present on fruit, those maintain the cellular membrane

integrity and respiration process of fruits. These results are supported by the by the

findings of Jocobi (1996) who found that Increased exposure time of hot water treatment

increased the weight loss % in fruits that was probably by damaging the waxy layer and

the rind tissue of the fruits. The higher incidences of fruit rot% in these fruit are also

indicated that these fruits became more susceptible to enter the pathogens. Previous

finding support these where it was observed that heat treatments increased the fruit loss

due to increase respiration rate (Klein, 1990).

Fruit those were stored at 6°C showed lower respirational changes it is because

the enzyme substrate link lost that possibly to indicated that to slow down the activity of

ACC, ACO, PG, PME, cellulose activities during storage (Teiz and Zeiger, 2006). On

other hand fruit those were stored at 8 ºC and tree held fruit showed higher respirational

changes due to higher temperature caused to increased activity of ACO, PG, PME,

cellulose in fruit. (Teiz and Zeiger, 2006). Lemon fruit showed lower respirational

changes at 5ºC due slowdown of ACO, PG activity during storage. Tahir et al. (2007)

reported that during storage of citrus fruit showed higher enzyme activities at 8ºC that

caused to higher respirational changes in sweet oranges. Moreover, Aresy et al. (2007)

also reported that PG, PME activities directly linked with respiration and resulted in

higher metabolic rates during storage in lemon fruit.

HWD exerted no adverse effects on the sensory attributes for both cultivars. HWT

maintained the freshness and improved their general appearance without affecting other

164

quality parameters. Organoleptic attributes including sourness, sweetness, texture, taste

and over quality. Fruit those were treated with HWD for 3 min at 53ºC showed maximum

sweetness, lower sourness higher texture, taste and overall quality as compared to fruit

those were treated with higher immersed time for 4 min at 53ºC and untreated fruits.

Similar results of improved general taste, texture over quality of the fruit without

alteration of their quality parameters were reported previously (Schirra and D’hallewin,

1997; Porat et al., 2000 ; Smilanick et al., 2003; Schirra et al.,2004; Yousaf and Hashim,

1992; Joyce et al., 2003; Eckert and ogawa, 1988). Fruit those were treated with HWTs

showed entirely cosmetic in nature on the outer peel of the very good eating quality at the

end of this evaluation. Thus, the major problems are pathological rather than

physiological. In spite of the significant improvement with the heat treatment, substantial

problems with fruit appearance remain, especially on the mature fruit after 90 days.


Hot water dipping for 3 min + TBZ for 5 min showed higher TSS (6.82 and 6.98

ºBrix), ascorbic acid (34.43 and 43.50 mg/100g), total sugar (5.06 and 6.44%),

reducing sugar (4.62 and4.44%) and non-reducing sugar (2.02 and 1.99%)

TSS/acidity ratio (5.57 and 4.77), maximum organoleptic scores and higher

phytonutrients such as total phenolic compound (145.80 and 149.90

mgGAE/100g), total antioxidants (57.25 and 60.44 %), total cartotenoids (14.49,

16.36 mg/100g), total flavonoids contents (49.03 and 51.98 mgCEQ/100g) and

total limonin contents (11.97 and 10.99 µg/mL) as compared to untreated fruits in

Ray Ruby and Shamber, respectively.

Hot water dipping improved the shelf life and quality of grapefruit.

Hot water dipping for 3 min + TBZ for 5 min showed ) with lower chilling (0.66

and 0.44%) and fruit rot (4.44 and 3.88%) as compared to untreated fruits in Ray

Ruby and Shamber, respectively.

165

4.4. Experiment-1 (a) Effects of wax coating on the quality and shelf

life of grapefruit Cv. Ray Ruby

Results 4.4.1a




at P≤0.05 regarding the effects of wax coating treatments and storage periods while

interaction between them was found non-significant. The fruits those were treated with

Chitosan @ 140 mg per fruit (T3) showed higher pH of 5.65 as compared to the fruits of

T2 (Chitosan @ 130 mg per fruit), T1 (Chitosan @ 120 mg per fruit) and To (without wax

coating) where pH values were 5.35, 4.93 and 4.40, respectively. Fruits those were

analysed 90 days after storage showed maximum pH of 5.52 than the fruits those were

analysed 60 and 30 days after storage where pH values were 5.12 and 4.60, respectively.


Total soluble solids (TSS) showed significant differences (P≤0.05) regarding the effects

of wax coating treatments, storage periods and their interaction (Figure 4.123a). Higher

total soluble solids (6.93 oBrix) were noted in the fruits those were treated with Chitosan

@ 140 mg per fruit (T3) as compared to the fruits of T2 (Chitosan @ 130 mg per fruit), T1

(Chitosan @ 120 mg per fruit) and To (without wax coating) where total soluble solids

were 6.61, 6.28 and 5.36 oBrix, respectively. The fruits those were analysed after 90 days

after storage showed higher TSS of 7.20 oBrix than the fruits those were analysed 60 and

30 days after storage where TSS values were 6.29 and 5.39 oBrix, respectively. The

interaction between wax coating treatments and storage periods showed that maximum

TSS of 8.16 oBrix was recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) when

analysed after 90 days storage and lower TSS of 5.502 oBrix was noted in fruits those

were without wax coating (To) when analysed 30 days after storage.

166

Figure 4.122a Effects of wax coating treatments on pH during storage (8oC) in

grapefruit cv. Ray Ruby.

To=without wax coating, T1= Chitosan @ 120 mg per fruit for 5

min dipping, T2= Chitosan @ 130 mg per fruit for 5 min dipping,

T3= Chitosan @ 140 mg per fruit for 5 min dipping (DAS=days

after storage).


Figure 4.123a Effects of wax coating treatments on TSS (oBrix) during storage





after storage).


0

1

2

3

4

5

6

7

To T1 T2 T3 To T1 T2 T3 To T1 T2 T3


pH

pH at 0 day = 3.51

0

1

2

3

4

5

6

7

8

9



TS

S (

oB

rix

)

TSS at 0 day = 4.63 oBrix

167


Statistically significant differences (P≤0.05) were found regarding the effects of wax

coating treatments and storage periods while interaction between them showed non-

significant results on total titratable acidity in the fruits (Figure 4.124a). The fruits those

were treated with Chitosan @ 140 mg per fruit (T3) showed lower titratable acidity of

1.34% as compared to the fruits of T2 (Chitosan @ 130 mg per fruit), T1 (Chitosan @ 120

mg per fruit) and To (without wax coating) where total titratable acidity values were 1.47,

1.57 and 1.70%, respectively. Fruits those were analysed 90 days after storage showed

lower titratable acidity of 1.38% than the fruits those were analysed 60 and 30 days after

storage where total titratable acidity values were 1.53 and 1.66%, respectively.


The effects of wax coating treatments, storage periods and their interaction were found

statistically significant (P≤0.05) regarding the TSS/acidity in the fruits of Ray Ruby

(Figure 4.125a). Higher TSS/acidity of 5.25 was recorded in the fruits those were treated

with Chitosan @ 140 mg per fruit (T3) as compared to the fruits of T2 (Chitosan @ 130

mg per fruit), T1 (Chitosan @ 120 mg per fruit) and To (without wax coating). The fruits

those were analysed 90 days after storage showed higher TSS/acidity of 5.33 than the

fruits those were analysed 60 and 30 days after storage where TSS/acidity values were

4.16 and 3.28, respectively. The interaction between wax coating treatments and storage

periods showed that higher TSS/acidity of 6.77 was noted in the fruits of T3 (Chitosan @

140 mg per fruit) when analysed 90 days after storage and lower TSS/acidity of 2.71 was

recorded in the fruits those were untreated (To) when analysed 30 days after storage.

168

Figure 4.124a Effects of wax coating treatments on total titratable acidity (%)

during storage (8oC) in grapefruit cv. Ray Ruby.




after storage).


Figure 4.125.a Effects of wax coating treatments on TSS/acidity ratio during





after storage).


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2



Acid

ity (

%)

Acidity at 0 day = 2.03%

0

1

2

3

4

5

6

7

8



TS

S/a

cid

ity


169


Ascorbic acid contents showed significant differences at P≤0.05 regarding the effects of

wax coating treatments, storage periods and their interaction in the fruits of Ray Ruby

(Figure 4.126a). The fruits those were treated with Chitosan @ 140 mg per fruit (T3)

showed higher ascorbic acid contents of 36.30 mg/100 g as compared to the fruits of T2

(Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit) while lower ascorbic

acid (32.85 mg/100 g) was recorded in the fruits those were without wax coating (To).

Fruits those were analysed 30 days after storage showed higher ascorbic acid contents of

37.01 mg/100 g than the fruits those were analysed 60 and 90 days after storage where

ascorbic acid contents were 35.39 and 32.15 mg/100 g respectively. The interactive effect

between wax coating treatments and storage periods showed that higher ascorbic acid

contents of 37.84 mg/100 g were noted in the fruits of T3 (Chitosan @ 140 mg per fruit)

when analysed 30 days after storage while lower ascorbic acid contents of 29.16 mg/100

g were recorded in the fruits those were without wax coating (To) when analysed 90 days

after storage.

Figure 4.126.a Effects of wax coating treatments on ascorbic acid contents





after storage).


0

5

10

15

20

25

30

35

40



Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 day = 37.23 mg/100 g

170


The effects of wax coating treatments, storage periods and their interaction showed

significant differences at P≤0.05 regarding the total sugar contents (Figure 4.127a). The

fruits those were treated with Chitosan @ 140 mg per fruit (T3) showed higher total sugar

contents of 6.24% as compared to the fruits of T2 (Chitosan @ 130 mg per fruit) and T1

(Chitosan @ 120 mg per fruit) while lower total sugar contents (4.82%) were recorded in

the fruits those were without wax coating (To). Fruits those were analysed 90 days after

storage showed higher total sugar contents of 6.11% than the fruits those were analysed

60 and 30 days after storage where total sugar contents were 5.46 and 5.05%,

respectively. The interaction between wax coating treatments and storage periods showed

that higher total sugar contents of 7.08% were noted in the fruits of T3 (Chitosan @ 140

mg per fruit) when analysed 90 days after storage. Whereas, lower total sugar contents of

4.60% were recorded in fruits those were without wax coating (To) when analysed 30

days after storage and these were at par with the fruits of T1 (Chitosan @ 120 mg per

fruit) and T2 (Chitosan @ 130 mg per fruit) when analysed 60 and 90 days after storage,

respectively.



coating treatments, storage periods and their interaction on reducing sugar contents in the

fruits of Ray Ruby (Figure 4.128a). Higher reducing sugar contents of 4.47% were noted

in fruits those were treated with Chitosan @ 140 mg per fruit (T3) as compared to the

fruits of T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit) while

lower reducing sugar contents of 3.66% were recorded in the fruits those were untreated

(To). The fruits those were analysed 90 days after storage showed maximum reducing

sugar contents (4.45%) than the fruits those were analysed after 60 and 30 days where

reducing sugars were 4.06 and 3.76%, respectively. The interaction between wax coating

treatments and storage periods showed that higher reducing sugar contents of 4.92% were

noted in the fruits those were treated with Chitosan @ 140 mg per fruit (T3) when

analysed 90 days after storage. While lower reducing sugar contents of 3.46, 3.63 and

3.64% were recorded in the fruits of To (without wax coating) and T2 (Chitosan @ 130

mg per fruit) when analysed 30, 60 and 30 days after storage, respectively.

171

Figure 4.127a Effects of wax coating treatments on total sugar contents (%)

during storage (8oC) in grapefruit Ray Ruby.




after storage).


Figure 4.128a Effects of wax coating treatments on reducing sugar contents

(%) during storage (8oC) in grapefruit cv. of Ray Ruby.




after storage).


0

1

2

3

4

5

6

7

8



To

tal

sug

ars

(%)

Total sugars at 0 day = 4.18%

0

1

2

3

4

5

6



Red

ucin

g s

ug

ars

(%)

Reducing sugars at 0 day = 3.07%

172



(p≤0.05) regarding the effects of wax coating treatments, storage periods and their

interaction on non-reducing sugar contents in the fruits of Ray Ruby (Figure 4.129a). The

fruits those were treated with Chitosan @ 140 mg per fruit (T3) showed higher non-

reducing sugar contents of 1.76% as compared to the fruits of T2 (Chitosan @ 130 mg per

fruit) and T1 (Chitosan @ 120 mg per fruit) while lower non-reducing sugar contents of

1.16% were recorded in the fruits those were untreated (To). The fruits those were

analysed 90 days after storage showed maximum non-reducing sugar contents (1.66%)

than the fruits those were analysed 60 and 30 days after storage where non-reducing

sugars were 1.39 and 1.29%, respectively and these were at par with each other. The

interaction between wax coating treatments and storage periods showed that higher non-

reducing sugar contents of 2.16% were noted in the fruits those were treated with

Chitosan @ 140 mg per fruit (T3) when analysed 90 days after storage. While minimum

non-reducing sugar contents of 1.13% were recorded in the fruits of To (without wax)

when analysed 30 days after storage and these were at par with the fruits of To (without

wax) when analysed 60 and 90 days after storage, T1 (Chitosan @ 120 mg per fruit) when

analysed 30 and 60 days after storage and T2 (Chitosan @ 130 mg per fruit) when

analysed 30 and 60 days after storage.

173

Figure 4.129a Effects of wax coating treatments on non-reducing sugar

contents (%) during storage (8oC) in grapefruit cv. Ray Ruby.




after storage).





(P≤0.05) regarding the effects of wax coating treatments, storage periods and their

interaction on total phenolic contents (TPC) in the fruits. The fruits those were treated

with Chitosan @ 140 mg per fruit (T3) showed higher TPC of 172.23 mg GAE/100 g as

compared to the fruits of T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg

per fruit) where TPC values were 168.00 and 154.56 mg GAE/100 g, respectively. While

lower TPC of 133.10 mg GAE/100 g were recorded in the fruits those were without wax

coating (To). The fruits those were analysed 90 days after storage showed minimum total

phenolic contents (143.85) than the fruits those were analysed 60 and 30 days after

storage where TPC values were 156.59 and 170.47 mg GAE/100 g, respectively. The

interaction between wax coating treatments and storage periods showed that higher TPC

of 180.93 and 176.51 mg GAE/100 g were noted in the fruits of T3 (Chitosan @ 140 mg

per fruit) and T2 (Chitosan @ 130 mg per fruit) when analysed 30 days after storage.

While lower TPC (109.17 mg GAE/100 g) were recorded in the fruits those were without

wax coating (To) when analysed 90 days after storage.

0

0.5

1

1.5

2

2.5



No

n-r

ed

ucin

g s

ug

ars

(%)

Non-reducing sugars at 0 day = 1.05%

174

4.4.1.2.2a Total antioxidants activities (% DPPH inhibition)

Total antioxidants activities showed significant differences at P≤0.05 regarding the

effects of wax coating treatments, storage periods and their interaction (Figure 4.131a).

Higher total antioxidants activities of 72.09% were recorded in the fruits those were

treated with Chitosan @ 140 mg per fruit (T3) as compared to the fruits of T2 (Chitosan @

130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit). While lower antioxidants

activities (51.92%) were noted in the fruits those were without wax coating (To). The

fruits those were analysed 30 days after storage showed higher antioxidants activities of

73.00% than the fruits those were analysed 60 and 90 days after storage where total

antioxidants activities were 62.78 and 53.35%, respectively. The interaction between wax

coating treatments and storage periods showed that higher antioxidants activities of

80.40% were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 30

days after storage and lower antioxidants activities (38.69%) were recorded in the fruits

those were untreated (To) when analysed 90 days after storage.

Figure 4.130a Effects of wax coating treatments on total phenolic contents (mg

GAE/100 g) during storage (8oC) in grapefruit cv. Ray Ruby.




after storage).


0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)

TPC at 0 day = 139.51 mg GAE/100 g

175

Figure 4.131a Effects of wax coating treatments on total antioxidants activities

(%DPPH inhibition) during storage (8oC) in grapefruit cv. Ray

Ruby.




after storage).




coating treatments, storage periods and their interaction on total flavonoids contents

(TFC) in fruits of Ray Ruby cultivar (Figure 4.132a). Fruits those were treated with

Chitosan @ 140 mg per fruit (T3) showed higher TFC of 57.27 mg CEQ/100 g and these

were at par with the fruits of T2 (Chitosan @ 130 mg per fruit) where TFC values were

56.07 mg CEQ/100 g followed by T1 (Chitosan @ 120 mg per fruit). While lower TFC of

43.02 mg CEQ/100 g were noted in the fruits those were without wax coating (To). The

fruits those were analysed 30 days after storage showed higher TFC (56.60 mg CEQ/100

g) as compared to the fruits those were analysed 60 and 90 days after storage where TFC

values were 51.69 and 45.47 mg CEQ/100 g, respectively. The interaction between wax

coating treatments and storage periods showed that higher TFC (61.14 and 59.92 mg

CEQ/100 g) were recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit) when analysed 30 days after storage, respectively and

these were at par with each other. Whereas, lower TFC of 34.47 mg CEQ/100 g were

0

10

20

30

40

50

60

70

80

90



%D

PP

H i

nh

ibit

ion

Total antioxidants at 0 day = 48.27%

176

noted in the fruits those were without wax coating (To) when analysed 90 days after

storage.



significant differences at P≤0.05 on total carotenoids contents in the fruits of Ray Ruby

cultivar (Figure 4.133a). The fruits those were treated with Chitosan @ 140 mg per fruit

(T3) and T2 (Chitosan @ 130 mg per fruit) showed higher total carotenoids contents of

17.09 and 16.97 mg/100 g, respectively and lower total carotenoids of 13.89 mg/100 g

were noted in the fruits of To (without wax coating). The fruits those were analysed 30

days after storage showed higher total carotenoids contents (17.11 mg/100 g) as

compared to the fruits those were analysed 60 and 90 days after storage where total

carotenoids contents were 16.08 and 14.25 mg/100 g, respectively. The interaction were

that TC decrease with increases storage period between wax coating treatments and

storage periods showed that maximum total carotenoids contents (17.68and 17.53 mg/100

g) were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130

mg per fruit) when analysed 30 days after storage, respectively and these were

statistically at par with each other. Whereas, minimum total carotenoids contents of 10.95

mg/100 g were recorded in the fruits those were without wax coating (To) when analysed

90 days after storage.

177

Figure 4.132a Effects of wax coating treatments on total flavonoids contents

(mg CEQ/100 g) during storage (8oC) in grapefruit cv. Ray

Ruby.




after storage).


Figure 4.133a Effects of wax coating treatments on total carotenoids contents





after storage).


0

10

20

30

40

50

60

70



TF

C (

mg

CE

Q/1

00

g)

TFC at 0 day = 41.13 mg CEQ/100 g

0

2

4

6

8

10

12

14

16

18

20



To

tal

caro

ten

oid

s (m

g/1

00 g

)

Total carotenoids at 0 day = 13.41 mg/100 g

178

4.4.1.2.5a Total limonin contents (µg\mL)


coating treatments, storage periods and their interaction on total limonin contents (TLC)

in the fruits (Figure 4.134a). Lower amounts of TLC (15.07 µg/mL) were noted in the

fruits those were treated with Chitosan @ 140 mg per fruit (T3) and higher TLC of 15.08

were recorded in the fruits those were without wax coating (To). The fruits those were

analysed 30 days after storage showed higher amounts of TLC (14.75 µg/mL) than the

fruits those were analysed 60 and 90 days after storage where TLC values were 13.57 and

12.21 µg/mL, respectively. The interaction between wax coating treatments and storage

periods showed that higher amounts of TLC (15.35, 15.14 and 15.04 µg/mL) were

recorded in the fruits of To (without wax coating), T1 (Chitosan @ 140 mg per fruit) and

To (without wax coating) when analysed 30 and 60 days after storage, respectively and

these were statistically at par with each other. While lower amounts of TLC of 10.19

µg/mL were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90

days after storage

Figure 4.134 a Effects of wax coating treatments on total limonin contents

(µg/mL) during storage (8oC) in grapefruit cv. of Ray Ruby.




after storage).


0

2

4

6

8

10

12

14

16

18



TL

C (

µg

/mL

)

TLC at 0 day = 16.77 µg/mL

179

4.4.1.3a. Physiological parameters


Chilling injury showed statistically significant differences (P≤0.05) regarding the effects

of wax coating treatments and storage periods while interaction between them was found

non-significant (Figure 135a). Higher index of chilling injury (2.77%) was noted in the

fruits those were without wax coating (To) and lower chilling injury indexes of 0.111 and

0.222% were recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan

@ 130 mg per fruit), respectively and these were statistically at par with each other. The

fruits those were analysed after storage 90 days showed higher index of chilling injury

(1.58%) than the fruits those were analysed 60 and 30 days after storage where chilling

injury indexes were 0.833 and 0.500%, respectively.

4.4.1.3.2a Fruit rot (%)

Statistically significant differences were found at P≤0.05 regarding the effects of wax

coating treatments, storage periods and their interaction on fruit rot (Figure 4.136a). The

fruits those were treated with Chitosan @ 140 mg per fruit (T3) and T2 (Chitosan @ 130

mg per fruit) showed lower fruit rot indexes of 1.66 and 2.11%, respectively and these

were at par with each other. While higher fruit rot index of 10.33% was noted in the fruits

those were without wax coating (To). Fruits those were analysed 90 days after storage

showed higher fruit rot index of 6.83% as compared to the fruits those were analysed 60

and 30 days after storage where fruit rot indexes were 4.75 and 2.41%, respectively. The

interaction between wax coating treatments and storage periods showed that higher fruit

rot index of 14.66% was recorded in the fruits those were without wax coating (To) when

analysed 90 days after storage. Whereas, fruits of T3 (Chitosan @ 140 mg per fruit) and

T2 (Chitosan @ 130 mg per fruit) showed lower fruit rot indexes (0.00 and 0.66%) when

analysed 30 days after storage, respectively and these were at par with each other.

180

Figure 4.135a Effects of wax coating treatments on chilling injury (%) during

storage (8oC) in grapefruit cv. of Ray Ruby.



T3= Chitosan @ 140 mg per fruit for 5 min dipping, (DAS=days

after storage)


Figure 4.136a Effects of wax coating treatments on fruit rot (%) during storage





after storage).


0

0.5

1

1.5

2

2.5

3

3.5

4

4.5



Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 day = 0 %

0

2

4

6

8

10

12

14

16



Fru

it r

ot

(%)

Fruit rot at 0 day = 0 %

181


Fruit weight loss showed significant differences (P≤0.05) regarding the effects of wax

coating treatments, storage periods and their interaction (Figure 4.137a). Lower loss in

weight of 2.665 was recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) and higher

loss in weight (11.44%) was noted in the fruits those were without wax coating (To). The

fruits those were analysed 90 days after storage showed higher loss weight of (8.08%) as

compared to the fruits those were analysed 60 and 30 days after storage where losses in

weights were 5.83 and 3.66%, respectively. The interaction between wax coating

treatments and storage periods showed that lower losses in weights of 1.33 and 2.00%

were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg

per fruit), respectively when analysed 30 days after storage and these were at par with

each other. Whereas, higher loss in weight of 15.33% was recorded in the fruits those

were without wax coating (To) when analysed 90 days after storage.

4.4.1.3.4a CO2 (ml kghr-1

)


significant differences at P≤0.05 on CO2 in the fruits (Figure 4.138a). Higher CO2 of 7.54

ml kghr-1 was recorded in the fruits those were without wax coating (To) and lower CO2

of 4.52 and 4.72 ml kghr-1 were noted in the fruits of T3 (Chitosan @ 140 mg per fruit)

and T2 (Chitosan @ 130 mg per fruit), respectively and these were at par with each other.

The fruits those were analysed 30 days after storage showed higher CO2 of 6.31 ml kghr-1

as compared to the fruits those were analysed 60 and 90 days after storage where CO2

values were 1.58 and 4.98 ml kghr-1, respectively. The interaction between wax coating

treatments and storage periods showed that lower CO2 values (4.14 and 4.40 ml kghr-1)


per fruit) when analysed 90 days after storage, respectively and these were at par with

each other. While, higher CO2 of 9.06 ml kghr-1 was recorded in the fruits those were

without wax coating (To) when analysed 30 days after storage.

182

Figure 4.137 a Effects of wax coating treatments on weight loss (%) during





after storage).


Figure 4.138a Effects of wax coating treatments on CO2 (ml kghr-1

) during





after storage).


0

2

4

6

8

10

12

14

16

18



Weig

ht

loss

(%

)

Weight loss at 0 day = 0%

0

1

2

3

4

5

6

7

8

9

10



CO

2 (

ml

kg

hr

-1)

CO2 at 0 day = 10.45 ml kghr-1

183

4.4.1.3.5a Ethylene (µL kghr-1

)


coating treatments, storage periods and their interaction on ethylene production in the

fruits (Figure 4.139a). The fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @

130 mg per fruit) showed lower rates of ethylene production (0.027 and 0.033 µL kghr -1),

respectively and these were at par with each other while higher rate of ethylene (0.071 µL

kghr-1) was noted in the fruits those were without wax coating (To). Fruits those were

analysed 90 days after storage showed higher rate of ethylene (0.064 µL kghr-1) as

compared to the fruits those were analysed 60 and 30 days after storage where ethylene

rates were 0.045 and 0.024 µL kghr-1, respectively. The interaction between wax coating

treatments and storage periods showed that higher rate of ethylene (0.103 µL kghr-1) was

recorded in the fruits those were without wax coating (To) when analysed 90 days after

storage. Whereas, lower rates of ethylene (0.013 and 0.016 µL kghr -1) were noted in the

fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit) when

analysed 30 days after storage, respectively and these were at par with the fruits of T3

(Chitosan @ 140 mg per fruit) and T1 (Chitosan @ 120 mg per fruit) when analysed 60

and 30 days after storage, respectively.

Figure 4.139a Effects of wax coating treatments on ethylene (µL kghr-1

) during





after storage).


0

0.02

0.04

0.06

0.08

0.1

0.12



Eth

yle

ne (

µL

kg

hr

-1)

Ethylene at 0 day = 0.021µL kghr-1

184





results on color score in the fruits (Figure 4.140a). Higher color scores of 7.00 and 6.77

were marked by the panellists for the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit), respectively and these were statistically at par with each

other. While minimum color score of 3.77 were marked by the panellists for fruits those

were without wax coating (To). The fruits those were analysed 90 days after storage

showed higher color score of 6.91 rated by the panellists than the fruits those were

analysed 60 and 30 days after storage where color scores were 5.58 and 4.91 liked by the

panellists, respectively.


Texture score showed significant differences at P≤0.05 regarding the effects of wax

coating treatments and storage periods while their interaction was found non-significant

(Figure 4.141a). Maximum texture scores of 8.11 and 7.66 were ranked by the panellists

for the fruit of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit),

respectively and these were at par with each other. Whereas, minimum texture score of

3.77 were rated by the panellists for the fruits those were without wax coating (To). The

fruits those were analysed 30 days after storage showed that higher texture score of 7.00

were marked by the panellists as compared to the fruits those were analysed 60 and 90

days after storage where texture scores were 6.25 and 5.41 marked by the panellists,

respectively.

185

Figure 4.140a Effects of wax coating treatments on color score during storage





after storage).


Figure 4.141a Effects of wax coating treatments on texture score during storage





after storage).


0

1

2

3

4

5

6

7

8

9

10



Co

lor s

core

Color score at 0 day = 2.55

0

1

2

3

4

5

6

7

8

9

10



Textu

re s

co

re

Texture score at 0 day = 4.11

186


The analysed data presented in Figure 4.142a showed significant differences (P≤0.05)

regarding the effects of wax coating treatments, storage periods and interaction between

them on taste score in the fruits. Maximum taste scores of 7.11 and 6.88 were marked by

the panellists for fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg

per fruit), respectively and these were at par with each other. While minimum taste score

of 5.16 liked by the panellists was recorded in fruits those were untreated (To). The fruits

those were analysed 90 days after storage showed higher taste score of 6.66 than the fruits

those were analysed 60 and 90 days after storage where taste scores were 5.66 and 5.16

were marked by respectively. The interaction between wax coating treatments and storage

periods showed that higher taste scores of 8.66 and 8.33 were ranked by the panellists for

of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit) when analysed

90 days after storage, respectively and these were at par with each other. Whereas, lower

taste scores (2.33 and 3.33) were marked by the panellists in the fruits those were without

wax coating (To) when analysed 90 and 60 days after storage, respectively and these were

at par with each other.



coating treatments and storage periods while their interaction showed non-significant

results for sourness score in the fruits of Ray Ruby (Figure 4.143a). Higher liked sourness

scores of 7.22 and 6.77 were marked by the panellists for fruits of T3 (Chitosan @ 140 mg

per fruit) and T2 (Chitosan @ 130 mg per fruit), respectively and these were at par with

each other. While, lower liked sourness score of 4.22 was marked by the panellists in the

fruits those were without wax coating (To). The fruits those were analysed 90 days after

storage showed maximum sourness score of 7.33 as compared to the fruits those were

analysed 60 and 30 days after storage where liked sourness scores were 5.75 and 5.25

respectively.

187

Figure 4.142a Effects of wax coating treatments on taste score during storage

(8oC) in grapefruit in Ray Ruby.




after storage).


Figure 4.143a Effects of wax coating treatments on sourness score during





after storage).


0

1

2

3

4

5

6

7

8

9

10



Tast

e s

co

re

Taste score at 0 day = 3.44

0

1

2

3

4

5

6

7

8

9

10



So

urn

ess

sco

re

Sourness score at 0 day = 2.88

188



regarding the effects of wax coating treatments and storage periods while interaction

between them was found non-significant for sweetness score. Maximum liked sweetness

scores of 7.55 and 7.00 were marked by the panellists for the fruits of T3 (Chitosan @

140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit), respectively and fruit of these

treatments were at par with each other. While, minimum sweetness scores of 5.41were

marked by the panellists for fruits those were untreated (To). The fruits those were

analysed 90 days after storage showed higher sweetness scores of 7.25 than the fruits

those were analysed 60 and 30 days after storage where sweetness scores were 6.00 and

5.41 respectively.


Overall quality score showed statistically significant differences at P≤0.05 regarding the

effects of wax coating treatments and storage periods while their interaction was found

non-significant (Figure 4.145a). Higher overall quality scores of 7.55 and 7.33 were

marked by the panellists for the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit), respectively and the fruit these treatments were at par with

each other. While, lower overall quality score of 4.44 was marked by the panellists for

those were without wax coating (To). The fruits those were analysed 90 days after storage

showed maximum overall quality scores of 7.50 as compared to the fruits those were

analysed after storage 60 and 30 days where overall quality scores were 6.41 and 5.33

respectively.

189

Figure 4.144a Effects of wax coating treatments on sweetness score during


ting, T1= Chitosan @ 120 mg per fruit for 5 min dipping, T2=

Chitosan @ 130 mg per fruit for 5 min dipping, T3= Chitosan @

140 mg per fruit for 5 min dipping, (DAS=days after storage).


Figure 4.145a Effects of wax coating treatments on overall quality score during





after storage).


0

1

2

3

4

5

6

7

8

9

10



Sw

eetn

ess

sco

re

Sweetness score at 0 day = 3.12

0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Overall quality score at 0 day = 3.17

190

4.4. Experiment-1(b) Effects of wax coating on the quality and shelf

life of grapefruit Cv. Shamber

Results 4.4.1b



The analysed data presented in Figure 4.146 b showed statistically significant differences

at P≤0.05 regarding the effects of wax coating treatments and storage periods while

interaction between them was found non-significant for pH in the fruits of Shamber

cultivar (Figure 4.144b). Higher pH of 5.95 and 5.80 were noted in fruits of T3 (Chitosan

@ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit), respectively and fruit of these

treatments were at par with each other. While lower value of pH (4.61) was noted in the

fruits those were without wax coating (To). The fruits those were analysed 90 days after

storage showed maximum pH of 5.82 than the fruits those were analysed 60 and 30 days

after storage where pH values were 5.38 and 4.95, respectively.


Total soluble solids (TSS) showed significant differences (P≤0.05) regarding the effects

of wax coating treatments, storage periods and their interaction (Figure 4.147b). Higher

total soluble solids (7.21 oBrix) were noted in the fruits those were treated with Chitosan

@ 140 mg per fruit (T3) as compared to the fruits of T2 (Chitosan @ 130 mg per fruit), T1

(Chitosan @ 120 mg per fruit) and To (without wax coating) where total soluble solids

were 6.91, 6.50 and 5.59 oBrix, respectively. The fruits those were analysed 90 days after

storage showed higher TSS of 7.47 oBrix than the fruits those were analysed 60 and 30

days after storage where TSS values were 6.54 and 5.64 oBrix, respectively. The

interaction between wax coating treatments and storage periods showed that maximum

TSS of 8.43 oBrix was recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) when

analysed 90 days after storage while lower TSS values of 5.25 and 5.53 oBrix were noted

in the fruits those were without wax coating (To) when analysed 30 days after storage,

respectively.

191

Figure 4.146 b Effects of wax coating treatments on pH during storage (8oC) in

grapefruit cv. Shamber.




after storage).


Figure 4.147 b Effects of wax coating treatments on TSS (oBrix) during storage





after storage).


0

1

2

3

4

5

6

7



pH

pH at 0 day = 3.67

0

1

2

3

4

5

6

7

8

9



TS

S (

oB

rix

)


192


Statistically significant differences P≤0.05) were found regarding the effects of wax


significant results for total titratable acidity (Figure 4.148 b). The fruits those were treated

with Chitosan @ 140 mg per fruit (T3) showed lower titratable acidity of 1.22% as

compared to the fruits of T2 (Chitosan @ 130 mg per fruit), T1 (Chitosan @ 120 mg per

fruit) and To (without wax coating) where total titratable acidity values were 1.35, 1.45

and 1.59%, respectively. Fruits those were analysed 90 days after storage showed lower

titratable acidity of 1.28% than the fruits those were analysed 60 and 30 days after storage

where titratable acidity values were 1.40 and 1.52%, respectively.


The effects of wax coating treatments, storage periods and their interaction were found

statistically significant (P≤0.05) regarding the TSS/acidity in the fruits of Shamber

(Figure 4.149 b). Higher TSS/acidity of 6.00 was recorded in the fruits those were treated

with Chitosan @ 140 mg per fruit (T3) and lower TSS/acidity of 3.54 was noted in the

fruits those were without wax (To). The fruits those were analysed 90 days after storage

showed higher TSS/acidity of 5.33 than the fruits those were analysed 60 and 30 days

after storage where TSS/acidity values were 4.16 and 3.28, respectively. The interaction

between wax coating treatments and storage periods showed that higher TSS/acidity of

7.60 was noted in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90 days

after storage. Whereas, lower TSS/acidity of 3.03 was recorded in the fruits those were

untreated (To) when analysed 30 days after storage and these were at par with the fruits of

To (without wax coating) and T1 (Chitosan @ 120 mg per fruit) when analysed 60 and 30

days after storage, respectively.

193

Figure 4.148b Effects of wax coating treatments on total titratable acidity (%)





after storage).


Figure 4.149b Effects of wax coating treatments on TSS/acidity ratio during





after storage).


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2



Acid

ity (

%)


0

1

2

3

4

5

6

7

8

9



TS

S/a

cid

ity

TSS/acidity = 2.50

194


Ascorbic acid contents showed significant differences at P≤0.05 regarding the effects of

wax coating treatments, storage periods and their interaction (Figure 4.150b). The fruits

those were treated with Chitosan @ 140 mg per fruit (T3) showed higher ascorbic acid

contents of 38.38 mg/100 g as compared to the fruits of T2 (Chitosan @ 130 mg per fruit)

and T1 (Chitosan @ 120 mg per fruit) while lower ascorbic acid contents (34.78 mg/100

g) were recorded in the fruits those were without wax coating (To). Fruits those were

analysed 30 days after storage showed higher ascorbic acid contents of 38.97 mg/100 g

than the fruits those were analysed 60 and 90 days after storage where ascorbic acid

contents were 35.39 and 32.15 mg/100 g, respectively. The interactive effect between

wax coating treatments and storage periods showed that higher ascorbic acid contents of

39.66 mg/100 g were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) when

analysed 30 days after storage while lower ascorbic acid contents of 30.92 mg/100 g were


storage.

Figure 4.150 b Effects of wax coating treatments on ascorbic acid contents





after storage).


0

5

10

15

20

25

30

35

40

45



Asc

orb

ic a

cid

(m

g/1

00 g

)


195



significant differences at (P≤0.05) regarding the total sugar contents (Figure 4.151b). The

fruits those were treated with Chitosan @ 140 mg per fruit (T3) showed higher total sugar

contents of 6.67% as compared to the fruits of T2 (Chitosan @ 130 mg per fruit), T1

(Chitosan @ 120 mg per fruit) and lower total sugar contents (5.23%) were recorded in

fruits those were without wax coating (To). Fruits those were analysed 90 days after

storage showed higher total sugar contents of 6.48% than the fruits those were analysed

60 and 30 days after storage where total sugar contents were 5.91 and 5.49%,

respectively. The interaction between wax coating treatments and storage periods showed

that higher total sugar contents of 7.48% were noted in the fruits of T3 (Chitosan @ 140

mg per fruit) when analysed 90 days after storage. Whereas, lower total sugar contents of

4.97% were recorded in the fruits those were without wax coating (To) when analysed 30

days after storage.



coating treatments, and storage periods while their interaction showed non-significant

results on reducing sugar contents (Figure 4.152b). Higher reducing sugar contents of

4.71% were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) as compared to the

fruits of T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit) while

lower reducing sugar contents of 3.90% were recorded in the fruits those were untreated

(To). The fruits those were analysed 90 days after storage showed maximum reducing

sugar contents (4.67%) than the fruits those were analysed 60 and 30 days after storage

where reducing sugars were 4.31 and 3.99%, respectively.

196

Figure 4.151b Effects of wax coating treatments on total sugar contents (%)





after storage).


Figure 4.152b Effects of wax coating treatments on reducing sugar contents

(%) during storage (8oC) in grapefruit cv. Shamber.




after storage).


0

1

2

3

4

5

6

7

8



To

tal

sug

ars

(%)


0

1

2

3

4

5

6



Red

ucin

g s

ug

ars

(%)


197



(P≤0.05) regarding the effects of wax coating treatments, storage periods and their

interaction on non-reducing sugar contents (Figure 4.153b). The fruits of T3 (Chitosan @

140 mg per fruit) showed higher non-reducing sugar contents of 1.96% as compared to

the fruits of T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit)

while lower non-reducing sugar contents of 1.32% were recorded in the fruits those were

without wax coating (To). The fruits those were analysed 90 days after storage showed

maximum non-reducing sugar contents (1.81%) than the fruits those were analysed 60

and 30 days after storage where non-reducing sugars were 1.60 and 1.49%, respectively

and these were at par with each other. The interaction between wax coating treatments

and storage periods showed that higher non-reducing sugar contents of 2.34% were noted

in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90 days after storage.

While lower non-reducing sugar contents of 1.28% were recorded in the fruits those were

without wax coating (To) when analysed 30 days after storage and these were at par with

the fruits of To (without wax coating) when analysed 60 and 90 days after storage, T1

(Chitosan @ 120 mg per fruit) when analysed 30 and 90 days after storage

Figure 4.153 b Effects of wax coating treatments on reducing sugar contents

(%) during storage (8oC) in grapefruit cv. Shamber.




after storage).


0

0.5

1

1.5

2

2.5

3



No

n-r

ed

ucin

g s

ug

ars

(%)


198




(p≤0.05) regarding the effects of wax coating treatments, storage periods and their

interaction on total phenolic contents (TPC). The fruits of T3 (Chitosan @ 140 mg per

fruit) and T2 (Chitosan @ 130 mg per fruit) showed higher TPC of 176.43 and 174.52 mg

GAE/100 g, respectively and these were statistically at par with each other. While lower

TPC of 137.47 mg GAE/100 g were recorded in the fruits those were without wax coating

(To). The fruits those were analysed 90 days after storage showed minimum total phenolic

contents (149.79 mg GAE/100 g) than the fruits those were analysed 60 and 30 days after

storage where TPC were 161.75 and 174.50 mg GAE/100 g, respectively. The interaction

between wax coating treatments and storage periods showed that higher TPC of 183.37

and 181.80 mg GAE/100 g were noted in the fruits of T3 (Chitosan @ 140 mg per fruit)

and T2 (Chitosan @ 130 mg per fruit) when analysed 30 days after storage and these were

at par with each other. Whereas, lower TPC (112.73 mg GAE/100 g) were recorded in the

fruits of To (without wax coating) when analysed 90 days after storage.

4.4.1.2.2b Total antioxidants activities (%DPPH inhibition)

Total antioxidants activities showed significant differences at p≤0.05 regarding the effects

of wax coating treatments, storage periods and their interaction (Figure 4.155b). Higher

antioxidants activities of 75.96% were recorded in the fruits of T3 (Chitosan @ 140 mg

per fruit) followed by T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per

fruit) where total antioxidants activities were 73.50 and 64.93%, respectively. While

lower antioxidants activities (53.88%) were noted in the fruits those were without wax

coating (To). The fruits those were analysed 30 days after storage showed higher

antioxidants activities of 76.17% than the fruits those were analysed 60 and 90 days after

storage where total antioxidants activities were 67.09 and 57.95%, respectively. The

interaction between wax coating treatments and storage periods showed that higher

antioxidants activities of 82.99% were noted in the fruits of T3 (Chitosan @ 140 mg per

fruit) and T2 (Chitosan @ 130 mg per fruit) when analysed 30 days after storage,

respectively. While, lower antioxidants activities (40.75%) were recorded in the fruits of

To (without wax coating) when analysed 90 days after storage.

199

Figure 4.154 b Effects of wax coating treatments on total phenolic contents (mg

GAE/100 g) during storage (8oC) in grapefruit cv. Shamber.




after storage).


Figure 4.155 b Effects of wax coating treatments on total antioxidants activities

(%DPPH inhibition) during storage (8oC) in grapefruit cv.

Shamber.




after storage).


0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)


0

10

20

30

40

50

60

70

80

90



%D

PP

H i

nh

ibit

ion

Total antioxidatnts at 0 day = 55.37%

200


Statistically significant differences (p≤0.05) were found regarding the effects of wax

coating treatments, storage periods and their interaction on total flavonoids contents

(TFC) in the fruits of Shamber (Figure 4.156b). Fruits those were treated with Chitosan

@ 140 mg per fruit (T3) showed higher TFC of 59.50 mg CEQ/100 g followed by the

fruits of T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per fruit) where

TFC values were 57.09 and 51.03 mg CEQ/100 g, respectively. While lower TFC of

44.89 mg CEQ/100 g were noted in the fruits those were without wax coating (To). The

fruits those were analysed 30 days after storage showed higher TFC (58.41 mg CEQ/100

g) as compared to the fruits those were analysed 60 and 90 days after storage where TFC

values were 53.66 and 47.32 mg CEQ/100 g, respectively. The interaction between wax

coating treatments and storage periods showed that higher TFC values (63.61 and 60.67

mg CEQ/100 g) were recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit) when analysed 30 days after storage, respectively and

these were at par with each other. Whereas, lower TFC of 36.77 mg CEQ/100 g were

noted in the fruits those were without wax coating (To) when analysed 90 days after

storage.



significant differences at p≤0.05 on total carotenoids contents (Figure 4.157b). The fruits

of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit) showed higher

total carotenoids contents of 18.98 and 18.82 mg/100 g, respectively and these were at par

with each other and lower total carotenoids contents (15.72 mg/100 g) were noted in the

fruits of To (without wax coating). The fruits those were analysed 30 days after storage

showed higher total carotenoids contents (18.93 mg/100 g) as compared to the fruits those

were analysed 60 and 90 days after storage where total carotenoids contents were 17.64

and 16.18 mg/100 g, respectively. The interaction between wax coating treatments and

storage periods showed that higher total carotenoids contents (19.51 and 19.35 mg/100 g)


per fruit) when analysed 30 days after storage, respectively and these were statistically at

par with each other. Whereas, lower total carotenoids contents of 12.72 mg/100 g were


storage.

201

Figure 4.156 b Effects of wax coating treatments on total flavonoids contents

(mg CEQ/100 g) during storage (8oC) in grapefruit cv. Shamber.




after storage).


Figure 4.157 b Effects of wax coating treatments on total carotenoids contents





after storage).


0

10

20

30

40

50

60

70



TF

C (

mg

CE

Q/1

00

g)


0

5

10

15

20

25



To

tal

caro

ten

oid

s (m

g/1

00 g

)


202

4.4.1.2.5b Total limonin contents (µg\mL)

Statistically significant differences (p≤0.05) were found regarding the effects of wax

coating treatments, storage periods and their interaction on total limonin contents (TLC)

in the fruits of Shamber (Figure 4.158b). Lower amounts of TLC (10.37 µg/mL) were

noted in the fruits T3 of (Chitosan @ 140 mg per fruit) and higher TLC of 13.18 µg/mL

were recorded in the fruits those were without wax coating (To). The fruits those were

analysed 30 days after storage showed higher amounts of TLC (12.87 µg/mL) than the

fruits those were analysed 60 and 90 days after storage where TLC values were 11.93 and

10.63 µg/mL, respectively. The interaction between wax coating treatments and storage

periods showed that higher amounts of TLC (13.56, 13.24 and 13.09 µg/mL) were

recorded in the fruits of To (without wax coating), T1 (Chitosan @ 140 mg per fruit) and

To (without wax coating) when analysed 30 and 60 days after storage, respectively and

these were statistically at par with each other. While lower amounts of TLC of 8.53

µg/mL were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90

days after storage.

Figure 4.158 b Effects of wax coating treatments on total limonin contents

(µg/mL) during storage (8oC) in grapefruit cv. Shamber.




after storage).


0

2

4

6

8

10

12

14

16



TL

C (

µg

/mL

)


203



Chilling injury showed statistically significant differences (P≤0.05) regarding the effects

of wax coating treatments and storage periods while interaction between them was found

non-significant (Figure 4.159 b). Higher index of chilling injury (2.44%) was noted in the

fruits those were without wax coating (To) and lower chilling injury indexes of 0.111 and

0.111% were recorded in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan

@ 130 mg per fruit), respectively and these were statistically at par with each other. The

fruits those were analysed 90 days after storage showed higher index of chilling injury

(1.33%) than the fruits those were analysed 60 and 30 days after storage where chilling

injury indexes were 0.75 and 0.41%, respectively and these were at par with each other.

4.4.1.3.2b Fruit rot (%)

Statistically significant differences were found at P≤0.05 regarding the effects of wax

coating treatments, storage periods and their interaction on fruit rot percentage (Figure

4.160b). The fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per

fruit) showed lower fruit rot indexes of 1.22 and 1.77%, respectively and these were at

par with each other. While higher fruit rot index of 9.66% was noted in the fruits those

were without wax coating (To). Fruits those were analysed 90 days after storage showed

higher fruit rot index of 6.25% as compared to the fruits those were analysed 60 and 30

days after storage where fruit rot indexes were 4.25 and 2.08%, respectively. The

interaction between wax coating treatments and storage periods showed that higher frui t

rot index of 14.00% was recorded in the fruits of To (without wax coating) when analysed

90 days after storage. Whereas, fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit) showed lower indexes (0.00% and 0.33%) when analysed

30 days after storage, respectively and these were at par with each other.

204

Figure 4.159b Effects of wax coating treatments on chilling injury (%) during





after storage).


Figure 4.160 b Effects of wax coating treatments on fruit rot (%) during storage





after storage).


0

0.5

1

1.5

2

2.5

3

3.5

4



Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 day = 0%

0

2

4

6

8

10

12

14

16



Fru

it r

ot

(%)

Fruit rot at 0 day = 0%

205


Weight loss showed significant differences (P≤0.05) regarding the effects of wax coating

treatments, storage periods and their interaction in the fruits of Shamber (Figure 4.161b).

Lower loss in weight of 2.44% was recorded in the fruits of T3 (Chitosan @ 140 mg per

fruit) and higher loss in weight of 11.22% was noted in the fruits those were without wax

coating (To). The fruits those were analysed 90 days after storage showed higher loss in

weight (7.83%) as compared to the fruits those were analysed 60 and 30 days after

storage where losses in weights were 5.50 and 3.41%, respectively. The interaction effect

between wax coating treatments and storage periods showed that lower losses in weights

of 1.33 and 1.66% were noted in the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit), respectively when analysed 30 days after storage and

these were at par with each other. Whereas, higher loss in weight of 15.33% was recorded

in the fruits of To (without wax coating) when analysed 90 days after storage.

4.4.1.3.4b CO2 (ml kghr-1

)


significant differences at P≤0.05 on CO2 in the fruits (Figure 4.162b). Higher CO2 of 7.38

ml kghr-1 was recorded in the fruits those were without wax coating (To) and lower CO2

of 4.50 and 4.68 ml kghr-1 were noted in the fruits of T3 (Chitosan @ 140 mg per fruit)

and T2 (Chitosan @ 130 mg per fruit), respectively and these were at par with each other.

The fruits those were analysed 30 days after storage showed higher CO2 of 6.19 ml kghr-1

as compared to the fruits those were analysed 60 and 90 days after storage where CO2

values were 5.48 and 5.00 ml kghr-1, respectively. The interaction between wax coating

treatments and storage periods showed that lower CO2 of 4.23 ml kghr-1 was noted in the

fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90 days after storage and these

were at par with the fruits of T2 (Chitosan @ 130 mg per fruit), T3 (Chitosan @ 140 mg

per fruit) and T2 (Chitosan @ 130 mg per fruit) when analysed 90 and 60 days after

storage, respectively. Whereas, higher CO2 of 8.88 ml kghr-1 was recorded in the fruits

those were without wax coating (To) when analysed 30 days after storage.

206

Figure 4.161 b Effects of wax coating treatments on weight loss (%) during





after storage).


Figure 4.162 b Effects of wax coating treatments on CO2 (ml kghr-1

) during





after storage).


0

2

4

6

8

10

12

14

16

18



Weig

ht

loss

(%

)


0

1

2

3

4

5

6

7

8

9

10



CO

2 (

ml

kg

hr

-1)

CO2 at 0 day = 10.03 ml kghr-1

207

4.4.1.3.5b Ethylene (µL kghr-1

)


coating treatments, storage periods and their interaction on ethylene production in the

fruits (Figure 4.163b). The fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @

130 mg per fruit) showed lower rates of ethylene production (0.031 and 0.036 µL kghr-1),

respectively and these were at par with each other while higher rate of ethylene (0.075 µL

kghr-1) was noted in the fruits of To (without wax coating). Fruits those were analysed 90

days after storage showed higher rate of ethylene (0.069 µL kghr-1) as compared to the

fruits those were analysed 60 and 30 days after storage where ethylene rates were 0.048

and 0.026 µL kghr-1, respectively. The interaction between wax coating treatments and

storage periods showed that higher rate of ethylene (0.113 µL kghr-1) was recorded in the

fruits those were without wax coating (To) when analysed 90 days after storage. Whereas,

lower rate of ethylene (0.016) was noted in the fruits of T3 (Chitosan @ 140 mg per fruit)

when analysed 30 days after storage and these were at par with the fruits of T2 (Chitosan

@ 130 mg per fruit), T3 (Chitosan @ 140 mg per fruit) and T1 (Chitosan @ 120 mg per

fruit) when analysed 30, 60 and 30 days after storage, respectively.

Figure 4.163b Effects of wax coating treatments on ethylene (µL kghr-1

) during





after storage).


0

0.02

0.04

0.06

0.08

0.1

0.12

0.14



Eth

yle

ne (

µL

kg

hr

-1)

Ethylene at 0 day = 0.017 µL kghr-1

208





results on color score in the fruits (Figure 4.162b). Higher color scores of 7.44 and 7.22

were marked by the panellists received for of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit), respectively and these were statistically at par with each

other. While minimum color score of 4.11 was given the panellists for the fruits those

were without wax coating (To). The fruits those were analysed 90 days after storage

showed higher color score of 7.25 than the fruits those were analysed 60 and 30 days after

storage where color scores were 6.08 and 5.25 respectively.


Texture score showed significant differences at P≤0.05 regarding the effects of wax

coating treatments and storage periods while their interaction was found non-significant

(Figure 4.163b). Maximum texture scores of 8.33 and 7.88 were ranked by the panellists

for fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per fruit),

respectively and these were at par with each other. Whereas, minimum texture score of

4.11 rated by the panellists for the fruits those were without wax coating (To). The fruits

those were analysed 30 and 60 days after storage showed higher texture scores of 7.08

and 6.58 respectively and these were at par with each other as compared to the fruits

those were analysed 90 days after storage where texture scores were 5.83.

209

Figure 4.164 b Effects of wax coating treatments on color score during storage





after storage).


Figure 4.165 b Effects of wax coating treatments on texture score during storage





after storage).


0

1

2

3

4

5

6

7

8

9

10



Co

lor s

core


0

1

2

3

4

5

6

7

8

9

10



Textu

re s

co

re


210


The analysed data presented in Figure 4.164 b showed significant differences (P≤0.05)

regarding the effects of wax coating treatments, storage periods and interaction between

them on the taste score. Maximum taste scores of 7.55 and 7.22 were marked by the

panellists for fruits of T3 (Chitosan @ 140 mg per fruit) and T2 (Chitosan @ 130 mg per

fruit), respectively and these were at par with each other. While minimum taste score of

3.66 were marked by the panellists for the fruits those were untreated (To). The fruits

those were analysed 90 days after storage showed higher taste score of 6.91 than the fruits

those were analysed 60 and 30 days after storage where taste scores were 6.08 and 5.58,

respectively and these were at par with each other. The interaction between wax coating

treatments and storage periods showed that higher taste scores of 8.66 was ranked by the

panellists for in the fruits of T3 (Chitosan @ 140 mg per fruit) when analysed 90 days

after storage and these were at par with the fruits of T2 (Chitosan @ 130 mg per fruit) and

T1 when analysed 90 and 60 days after storage, respectively. Whereas, lower taste scores

(2.66 and 3.66) were marked by the panellists for the fruits of To (without wax coating)

when analysed 90 and 60 days after storage, respectively and these were at par with each

other.



coating treatments and storage periods while their interaction showed non-significant

results for sourness score in the fruits of Shamber (Figure 4.165 b). Higher liked sourness

scores of 7.11, 6.88 and 6.55 were marked by the panellists for the fruits of T3 (Chitosan

@ 140 mg per fruit), T2 (Chitosan @ 130 mg per fruit) and T1 (Chitosan @ 120 mg per

fruit), respectively and these were at par with each other. While, lower liked sourness

score of 4.44 marked by the panellists was noted in the fruits those were without wax

coating (To). The fruits those were analysed 90 days after storage showed maximum

sourness score of 7.41 as compared to the fruits those were analysed 60 and 30 days after

storage where sourness scores were 6.00 and 5.33 respectively.

211


The analysed data presented in Figure 4.166b showed significant differences (P≤0.05)

regarding the effects of wax coating treatments and storage periods while interaction

between them was found non-significant for sweetness scores. Maximum sweetness

scores of 7.77 and 7.33 were marked by the panellists for the fruits of T3 (Chitosan @ 140

mg per fruit) and T2 (Chitosan @ 130 mg per fruit), respectively and these were at par

with each other. While, minimum sweetness score of 4.55 marked by the panellists for the

fruits those were untreated (To). The fruits those were analysed 90 days after storage

showed higher sweetness score of 7.41 than the fruits those were analysed 60 and 30 days

after storage where sweetness scores were 6.33 and 5.75 respectively.

Figure 4.166b Effects of wax coating treatments on taste score during storage





after storage).


0

1

2

3

4

5

6

7

8

9

10



Tast

e s

co

re


212

Figure 4.167 b Effects of wax coating treatments on sourness score during

storage (8oC) in grapefruit in Shamber.




after storage).


Figure 4.168b Effects of wax coating treatments on sweetness score during





after storage).


0

1

2

3

4

5

6

7

8

9

10



So

urn

ess

sco

re


0

1

2

3

4

5

6

7

8

9

10



Sw

eetn

ess

sco

re


213

4.2.1.4.6b Overall quality scores

Overall quality scores showed statistically significant differences at P≤0.05 regarding the

effects of wax coating treatments and storage periods while their interaction was found

non-significant (Figure 4.167b). Higher overall quality scores of 7.77 and 7.55 were

marked by the panellists for the fruits of T3 (Chitosan @ 140 mg per fruit) and T2

(Chitosan @ 130 mg per fruit), respectively and these were at par with each other. While,

lower overall quality score of 4.77 were marked by the panellists for the fruits those were

without wax coating (To). The fruits those were analysed 90 days after storage showed

maximum overall quality score of 7.66 as compared to the fruits those were analysed 60

and 30 days after storage where overall quality scores were 6.75 and 5.66 respectively.

Figure 4.169b Effects of wax coating treatments on overall quality score during

storage (8oC) in grapefruit cv. of Shamber.




after storage).



Films and edible coatings are defined as “a thin application of material that forms

a protective covering around an edible commodity and can be consumed along with the

coated product” (Guilbert, 1986). Films and coatings have been used traditionally to

improve appearance and to conserve food products. The most common examples are the

0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Overall quality score at 0 day= 3.77

214

wax coatings for fruits, which are used in China as far back as 12 th century (Dalal et al.,

1971). Chitosan is a modified natural carbohydrate polymer derived from chitin which

has been found in a wide range of natural sources like crustaceans, fungi, insects and

some algae (Tolamite et al., 2000).

The results elucidated that highest pH was observed in the fruits treated with

chitosan @ 140 mg per fruit while it was lowest in fruits treated with lower doses of

chitosan or in uncoated fruit. This change in pH during storage period might be due to the

alteration of biochemical condition of fruit or lower rate of respiration and metabolic

activity of fruit. The pH increases at a slower rate particularly at the end of storage period

due to saturation of atmosphere inside the pack with water vapors. These results are

similar with findings of Biasi and Zanette (2000) who revealed that gibberellic acid and

wax solution slightly increased pH during storage in sweet lime. Higher doses of chitosan

and storage period showed higher total soluble solid values than the fruits treated with

lower doses and uncoated fruit. The changes in TSS are directly correlated with

hydrolytic changes in the starch concentration during the storage period. These changes

result in the conversion of starch to sugar, which in an important index of ripening

process (Kays, 1997).

Many different solutes are accumulated in vacuoles of cells as the fruit ripens.

Fruit contain much starch that hydrolysis to sugars as fruit ripens. At the same time,

protopectin in the cell wall hydrolyzes to soluble pectins due to which the total soluble

contents of such fruits gradually increase after harvest (Ryogo, 1988). These results

correlate with the findings of Ladaniya and Sonker (1997) who reported that maximum

values of TSS were observed when fruits were waxed and stored for up to 60 days of

storage. Likewise, fruits treated with higher doses of chitosan showed lower acidity than

fruits treated with lower doses. In earlier studies, it has also been reported that during the

ripening of fruits, malic acid disappear first followed by citric acid (which result in

reduction in amount of acidity); suggesting the catabolism of citrate via malate (Mattoo et

al., 1975; Salunkhe and Desai, 1984). Disappearance of malic and citric acid during

ripening process may be the main factor responsible for the reduction in titratable acidity

during the storage. The microorganisms may use citric acid as the carbon source, hence

resulting in reduction in titratable acidity (Badshah et al., 1997; Batu and Thompson,

1998). In another study, Jiang and Li (2001) investigated the effect of chitosan coating on

longan fruit and found that the titratable acidity was decreased during storage. Fruit

treated with chitosan @ 140 mg per fruit showed significantly higher ascorbic acid

215

contents after 30 days as compared to the fruits treated with lower doses and control

fruits. After 30 days storage then reduction trend was observed in all treatment of

chitosan however untreated fruits showed more reduction of Vitamin C after 90 days

storage in both grapefruit cultivators. This might be due to slow ripening and

compositional changes of gases in stored fruit. Oxidation of ascorbic acid may be caused

by several factors including exposure to oxygen, metals, light, heat and alkaline pH

(Sritananan et al., 2005). However, fruit coatings may serve as a protective layer and

control the permeability of O2 and CO2 (Srinivasa et al., 2002). Untreated and lower

concentration showed more reduction of ascorbic acid after 60 and 90 days due to fast

oxidation and changes of oxygen level. The results congregates with the findings of Jiang

et al. (2004) who narrated that ascorbic acid content decreased when longan fruit was

coated with lower chitosan level at low temperature (2°C).

Fruit treated with chitosan showed significantly higher TS, RS, NRS during

storage expect control. Total sugars of the fruits are considered one of the basic criteria to

evaluate the fruit ripening. It is clear from the results that at the time of harvest the sugars

were very low but with the passage of time, ripening was enhanced resulting in the

increase of total sugars (Wills and Rigney, 1979). In a study, Gul et al. (1990) reported

that the storage period prolongs the rate of respiration, transpiration and other metabolic

changes in citrus. Application of chitosan @140 mg per fruit delayed the respiration and

ripening; and thus the ripening and changes associated with ripening tent to slow down

the pattern of accumulation of sucrose. Chitosan affects the enzymes present in the fruit,

especially the pectinases enzyme by decreasing its activity; which might affect the other

enzymes viz. acid invertase and sucrose synthase responsible for the sucrose metabolism

and starch accumulation (Wang et al., 1993). With the passage of time, respiration,

transpiration and other metabolic processes enhanced. Due to this starches were converted

into sugars and reducing sugar quantity was increased. Fruit treated with chitosan @140

mg per fruit showed maximum TSS/acidity which might be due to change in respiration

pattern in cell membrane. Maximum reduction were noted at lower concentration and

uncoated fruit after 90 day which might be due to to conversion of starch to sugars as a

result of moisture loss and increased acidity due to physiological changes during storage

(Wills and Rigney, 1979). With the passage of time, degradation of ascorbic acid leads

towards increased TSS. In another study, Manazano and Diaz (2001) reported that

„Valencia‟ oranges fruits were harvested, sorted, graded and treated with a wax coating

(Primafresh and Cerabar “Dr”) and it was found that TSS/acid ratio was increased with

216

the passage of time. Chitosan possesses polycationic properties which provide this

polymer with the possibility of forming films by the breakage of polymer segments and

subsequently reforming the polymer chain into a film matrix or gel; and this can be

achieved by evaporating a solvent, thus creating hydrophilic and hydrogen bonding

and/or electrolytic and ionic cross linking (Butler et al., 1996). Fruit treated with chitosan

showed maximum quantities of phytochemical in fruit after 30 and 60 days of storage

than the one seen during end of experiment. Higher doses of chitosan showed lower

reduction as compared to fruit those were uncoated and treated with lower concentration.

Maximum quantities of TPC, TAA, TC and TF were recorded after 30 and 60

days after storage. Chitosan may inhibit the activity of polyphenol oxidase, an enzyme

that is involved in the process of phenolic compound degradation (Jiang and Li, 2001). It

is well known that the bioactivity of chitosan, including antioxidant ability, is mainly

attributed to the activity of hydroxyl and amino groups. There are 3 kinds of hydrogen

sources: NH2 of C2 and OH of C3 and C6. It is difficult for 3-OH to take part in the

reaction because of steric hindrance (Xie et al., 2001). Fruit treated with chitosan showed

maximum TAA and TF, TC after 90 days as compared to fruit those were analyzed after

90 days storage this is due to chitosan have ability to develop a modified system for

exchange of gases. Untreated fruit and lower concentration of chitosan showed maximum

reduction of these compounds after 90 days be due to breakdown of cell structure in order

to senescence phenomena during storage (Macheix et al., 1990). Fruit treated with

chitosan @ 140 mg per fruit showed maximum TP and TL after 30 and 60 days of storage

of both varieties than fruits treated with lower concentration or control. Untreated fruits

suffered more enzymatic changes than those treated with chitosan. This is temporary

because, at a more advanced stage of oxidation, the molecules gradually lose this

property, and there is a drastic reduction in TL. Several other studies have reported the

similar results (Gardner, 1995; Andereasen et al., 2001). Fruit treated with chitosan

showed no Cl, FR, during whole storage period this due to reason explained by the Liu et

al. (2007) who explained the produced antibacterial membranes from a mixture of

hydrolyzed starch that causes the semipermeable barrier in cell wall which prevents

spores entering in cell wall. Cuticle layer mainly suffers water losses and results in crack

in fruit. These cuticle layers can be damaged easily and can form micro-cracks, which can

cause moisture loss (Cohen et al., 1990). Earlier, Romanazzi et al. (2002) and Chien et al.

(2005) reported the similar results. Lower fruit weight losses were noted in fruit those

were treated with chitosan after 90 days of storage. This was mainly because the chitosan

217

was the derivative of the amino cellulose with the feature of polycation and it can gather

the positive ion at the surface of negative ion. The interaction between the positive ion

and negative ion makes it have the biological adhesive property due to which it can

adhere the surrounding molecule to form the colloidal film which have the unique

property (Ali et al., 2005). Chitosan @ 140 mg per fruit showed decrease in respiration

rate which might be reduction of oxygen supply on the fruit surface which may have

inhibited respiration (Yonemoto et al., 2002). In another study, Du et al. (1997) reported

that application of chitosan coating inhibited respiration rates of fruit.

Sensory evaluation for both varieties showed that the fruits treated with chitosan

showed more sweetness and sourness trend was decreased when noted after 90 day of

storage. This increase in sweetness might be the result of fast ripping of fruits resulting in

increased sugar during storage. Sugar level was lower in untreated and control fruit after

90 days of storage. Sourness was reduced by chitosan application and increased trend was

noted in case of untreated fruit which may be due to oxidation of citric acid. Earlier, Gul

et al. (1990), Doreyappa and Huddar (2001), and Srinivasa et al. (2002) also found that

sweetness was increased in fruits. Fruit sweetness may be attributed to the presence of

organic acids in the fruits which are major contributor of fruit taste (Kays, 1991). Fruit

texture is mainly attributed to cell wall integrity and stored carbohydrates such as pectin,

starch etc. Chitosan maintained fruit textural score after 90 days storage which may be

due to decreased breakdown of insoluble pectin substances (Weichmann, 1987). Coated

fruits showed overall good quality than uncoated fruit. This improvement in quality may

be attributed to the increases in organic acids during senescence (Baldwin et al., 1994).

Untreated fruit showed lower quality which was indicated through lowest lowest scores.

This poor quality might be due to the change in carbohydrates, proteins, amino acids,

lipids and phenolic compounds that can influence the fruits (Malundo et al., 2001).

4.4.3 Conclusion

Chitosan application @ 140 mg per fruit-1 maintained the fruit quality parameters

such as TSS (6.93 and 7.21ºBrix), ascorbic acid (36.30 and 38.38mg/100g), total

sugar (6.24 and 6.67%), reducing sugar (4.47 and 4.71%) and non-reducing sugar

(1.76 and 1.96%), TSS/acidity (5.25 and 6.00), maximum organoleptic scores and

higher phytonutrients total phenolic compound (172.32 and 176.43

mgGAE/100g), total antioxidants (72.09 and75.96 %), Total cartotenoids (17.09

and 18.98 mg/100g), total flavonoids contents (52.27 and 59.50 mgCEQ/100g)

218

and total limonin contents (15.08 and 12.87 µg/mL) Organoleptic scores and

decreased the sourness and TA after 90 days of storage.

Chitosan coating also protected the grapefruit from disease minimum chilliuris

injury (1.58 and 1.33%) and fruit rot (0.66 and 0.33%) as compared to fruits those

were without wax coating analysed 90 days after storage of Ray Ruby and

Shamber, respectively.

It is recommended that chitosan @ 140 mg per fruit-1 is the best doses that is very

effective in improving the overall quality and shelf life of grapefruit.

219

4.5. Experiment-1 (a) Effects of pre-harvest spray of salicylic (SA) and

Methyl Jasmonate (MeJA) on the chilling

injury, decay and phytochemicals during the

storage in grapefruit Cv. Ray Ruby

Results 4.5.1a



The analysed data presented in Figure 4.170 a showed statistically significant differences

at P≤0.05 regarding the effects of treatments (SA and MeJA) and storage periods while

interaction between them was found non-significant for pH in the fruits of Ray Ruby. The

fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5

mM (T6) showed higher values of pH (5.17 and 5.11), respectively and these were

statistically at par with each other as compared to the fruits of other treatments. While

lower pH values of 4.24, 4.25 and 4.32 were recorded in the fruits of To (control), T4

(methyl jasmonate @ 3 mM) and T1 (salicylic acid @ 6 mM), respectively and these were

at par with each other. The fruits those were analysed 90 days after storage showed higher

pH of 4.93 than the fruits those were analysed 60 and 30 days after storage where pH

values were 4.74 and 4.49, respectively.

This part of study has been submitted in Post-harvest biology technology

2013-2014 (Accepted) under the title and author Effects of pre harvest

application of Methyl Jasomante on fruit quality at Harvest and during

storage of grapefruit. Ahmed, W., A. Saeed, Mailk, A.U., Ahmed.

Rashid.

Ahmed W., Ahmed S., Liaquat A and H. Imatiaz. 2015. Effects of pre-

harvest spray of salicylic (SA) and methyl jasmonate (MeJA) on the

phytochemicals and physiological changes during the storage of

grapefruit Cv. Ray Ruby. Int. J. of Biosciences. Vol. 6, No. 1, p. 269-282.

220

Figure 4.170a Effects of pre-harvest spray of salicylic acid (SA) and methyl


Ray Ruby.

To=control, T1=salicylic acid @ 6 mM, T2=salicylic acid @ 8 mM,

T3=salicylic acid @ 12 mM, T4=methyl jasmonate @ 3 mM,

T5=methyl jasmonate @ 4 mM, T6=methyl jasmonate @ 5 mM

(DAS=days after storage).



Statistically significant differences (P≤0.05) were found regarding the effects of

treatments (SA and MeJA) storage periods and their interaction on total soluble solids

(TSS) in the fruits of Ray Ruby (Figure 4.169a). Higher TSS values (5.92 and 5.83 oBrix)

were noted in the fruits of T3 (salicylic acid @ 12 mM) and T6 (methyl jasmonate @ 5

mM), respectively and these were at par with each other. While lower TSS values of 5.08

and 5.14 oBrix were recorded in the fruits of To (control) and T4 (methyl jasmonate @ 3

mM), respectively and these were at par with each other. The fruits those were analysed

90 days after storage showed higher TSS of 5.73 oBrix as compared to the fruits those

were analysed 60 and 30 days after storage where TSS contents were 5.46 and 5.28 oBrix,

respectively.The interaction between treatments (SA and MeJA) and storage periods

showed that higher TSS values of 6.32 and 6.24 oBrix were recorded in the fruits those

were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6)

when analysed 90 days after storage, respectively and these were at par with each other.

Whereas, lower TSS of 4.91 oBrix was noted in the control fruits (To) when analysed 30

days after storage and these were at par with the fruits of T4 (Methyl jasmonate @ 3 mM),

0

1

2

3

4

5

6

To T1 T2 T3 T4 T5 T6 To T1 T2 T3 T4 T5 T6 To T1 T2 T3 T4 T5 T6


pH

pH at 0 day = 3.56

221

To (control) and T1 (Salicylic acid @ 6 mM) when analysed 30 and 60 days after storage,

respectively (Figure 4.171a).


jasmonate (MeJA) on TSS (oBrix) during storage (8

oC) in the

fruits of Ray Ruby.







The effects of treatments (SA and MeJA) and storage periods showed statistically

significant differences (P≤0.05) while interaction between them was found non-

significant for total titratable acidity (Figure 4.172a). The fruits those were sprayed with

salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed lower titratable

acidity of 1.39 and 1.44%, respectively and these were statistically at par with each other

as compared to the fruits of other treatments. While higher titratable acidity of 1.79% was

recorded in the control fruits (To). The fruits those were analysed 30 days after storage

showed higher titratable acidity of 1.67% than the fruits those were analysed 60 and 90

days after storage where titratable acidity values were 1.58 and 1.48%, respectively.



treatments (SA and MeJA) storage periods and their interaction on TSS/acidity ratio in

the fruits of Ray Ruby (Figure 4.173 a). Fruits those were sprayed with salicylic acid @

0

1

2

3

4

5

6

7



TS

S (

oB

rix

)


222

12 mM (T3) showed higher TSS/acidity of 4.29 as compared to the fruits of other

treatments while lower TSS/acidity (2.83) was recorded in the fruits those were untreated

(To). The fruits those were analysed 90 days after storage showed higher TSS/acidity of

3.94 than the fruits those were analysed 60 and 30 days after storage where TSS/acidity

values were 3.49 and 3.18, respectively. The interaction between treatments (SA and

MeJA) and storage periods showed that higher TSS/acidity values of 4.94 and 4.67 were

recorded in the fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl

jasmonate @ 5 mM (T6) when analysed 90 days after storage, respectively and these were

at par with each other. Whereas, lower TSS/acidity of 2.58 was noted in the control fruits

(To) when analysed 30 days after storage and these were at par with the fruits of T1

(salicylic acid @ 6 mM) and To (control) when analysed 30 and 60 days after storage,

respectively.









0

0.5

1

1.5

2

2.5



Acid

ity (

%)


223


jasmonate (MeJA) on TSS/acidity ratio during storage (8oC) in








The effects of treatments (SA and MeJA), storage periods and their interaction showed

statistically significant differences at P≤0.05 regarding the ascorbic acid contents (Figure

4.174a). Fruits those were sprayed with salicylic acid @ 12 mM (T3) showed higher

ascorbic acid contents of 35.86 mg/100 g and these were at par with the fruits T6 (methyl

jasmonate @ 5 mM), T2 (salicylic acid @ 8 mM) and T5 (methyl jasmonate @ 4 mM),

respectively. While, lower ascorbic acid contents of 31.64 mg/100 g were noted in control

fruits (To). The fruits those were analysed 30 days after storage showed higher ascorbic

acid contents of 36.10 mg/100 g as compared to the fruits those were analysed 60 and 90

days after storage where ascorbic acid contents were 34.47 and 32.89 mg/100 g,

respectively. The interaction between treatments (SA and MeJA) and storage periods

showed that higher ascorbic acid contents of 36.55 mg/100 g were recorded in the fruits

those were sprayed with salicylic acid @ 12 mM (T3) when analysed 30 days after storage

and these were at par with the fruits of T6 (methyl jasmonate @ 5 mM), T2 (salicylic acid

@ 8 mM) and T5 (methyl jasmonate @ 4 mM) when analysed 30 days after storage,

0

1

2

3

4

5

6



TS

S/a

cid

ity


224

respectively. Whereas, lower ascorbic acid contents of 27.69 mg/100 g were noted in the

control fruits (To) when analysed 90 days after storage.











significant differences (P≤0.05) while their interaction was found non-significant for total

sugar contents (Figure 4.175a). The fruits those were sprayed with salicylic acid @ 12

mM (T3) and methyl jasmonate @ 5 mM (T6) showed higher total sugar contents of 5.88

and 5.77%, respectively and these were statistically at par with each other as compared to

the fruits of other treatments. While, lower total sugar contents of 4.89% were recorded in

the control fruits (To). The fruits those were analysed 90 days after storage showed higher

total sugar contents (5.75%) than the fruits those were analysed 60 and 30 days after

storage where total sugar contents were 5.44 and 4.93%, respectively.

0

5

10

15

20

25

30

35

40



Asc

orb

ic a

cid

(m

g/1

00 g

)


225



regarding the treatments (SA and MeJA) and storage periods while interaction between

them was found non-significant for reducing sugar contents. The fruits those were

sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed

higher reducing sugar contents of 3.74 and 3.63%, respectively as compared to the fruits

of other treatments. While, lower reducing sugar contents 3.08 were recorded in the

control fruits (To). The fruits those were analysed 90 days after storage showed higher

reducing sugar contents (3.58%) than the fruits those were analysed 60 and 30 days after

storage where reducing sugar contents were 3.41 and 3.24%, respectively.


jasmonate (MeJA) on total sugar contents (%) during storage







0

1

2

3

4

5

6

7



To

tal

sug

ars

(%)


226


jasmonate (MeJA) on reducing sugar contents (%) during









treatments and storage periods while interaction between them was found non-significant

for non-reducing sugar contents (Figure 4.177a). The fruits those were sprayed with

methyl jasmonate @ 5 mM (T6) showed higher non-reducing sugar contents (2.14%) and

these were at par with the fruits of T3 (salicylic acid @ 12 mM) and T2 (salicylic acid @ 8

mM). While lower non-reducing sugar contents of 1.74 and 1.81% were noted in the

fruits of To (control and T1 (salicylic acid @ 8 mM), respectively and these were at par

with each other. The fruits those were analysed 90 days after storage showed higher non-

reducing sugar contents (2.17%) as compared to the fruits those were analysed 60 and 30

days after storage where non-reducing sugars were 2.03 and 1.68%, respectively.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5



Red

ucin

g s

ug

ars

(%)


227











Total phenolic contents (TPC) showed significant differences (p≤0.05) regarding the

effects of treatments (SA and MeJA) and storage periods while their interaction was

found non-significant (Figure 4.178a). The fruits those were sprayed with salicylic acid

@ 12 mM (T3) showed higher total phenolic contents of 166.29 mg GAE/100 g as

compared to the fruits of all other treatments. While lower total phenolic contents of

138.76 mg GAE/100 g were recorded in the control fruits (To). The fruits those were

analysed 30 days after storage showed higher total phenolic contents (161.51 mg

GAE/100 g) than the fruits those were analysed 60 and 90 days after storage where total

phenolic contents were 153.00 and 147.25 mg GAE/100 g, respectively.

4.5.1.2.2a Total antioxidants activities (%DPPH inhibition)


treatments (SA and MeJA), storage periods and their interaction on total antioxidants

activities in the fruits of Ray Ruby (Figure 4.179a). Higher total antioxidants activities

(72.63 and 71.37%) were recorded in the fruits of T3 (salicylic acid @ 12 mM) and T6

0

0.5

1

1.5

2

2.5

3



No

n-r

ed

ucin

g s

ug

ars

(%)


228

(methyl jasmonate @ 5 mM), respectively and these were at par with each other. While

lower antioxidants activities of 52.02% were noted in the fruits those were untreated (To).

The fruits those were analysed 30 days after storage showed higher total antioxidants

activities (71.21%) as compared to the fruits those were analysed 60 and 90 days after


interaction between treatments (SA and MeJA) and storage periods showed that higher

antioxidants activities of 78.33 and 77.39% were recorded in the fruits those were sprayed

with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) when analysed 30

days after storage, respectively and these were at par with each other. Whereas, lower

antioxidants activities of 39.69% were noted in the control fruits (To) when analysed 90

days after storage.









0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)


229


jasmonate (MeJA) on total antioxidants (%DPPH inhibition)








(P≤0.05) regarding the effects of treatments (SA and MeJA), storage periods and their

interaction on total flavonoids contents (TFC) in the fruits. Higher amounts of TFC

(55.74 and 53.43 mg CEQ/100 g) were recorded in the fruits of T3 (salicylic acid @ 12

mM) and T6 (methyl jasmonate @ 5 mM), respectively as compared to the fruits of other

treatments. While lower TFC of 38.68 mg CEQ/100 g were noted in the fruits those were

untreated (To). The fruits those were analysed 30 days after storage showed higher total

TFC (54.81 mg CEQ/100 g) than the fruits those were analysed 60 and 90 days after

storage where total TFC values were 48.28 and 42.23 mg CEQ/100 g, respectively. The


amounts of TFC (60.55 and 58.50 mg CEQ/100 g) were recorded in the fruits those were

sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) when

analysed 30 days after storage, respectively. While, lower amounts of TFC (29.39 mg

CEQ/100 g) were noted in the control fruits (To) when analysed 90 days after storage.

0

10

20

30

40

50

60

70

80

90



%D

PP

H i

nh

ibit

ion

Total antioxidants at 0 day = 71.23%

230



treatments (SA and MeJA), storage periods and their interaction on total carotenoids

contents in the fruits of Ray Ruby (Figure 4.181a). Higher amounts of total carotenoids

contents of 16.40% and 16.32 mg/100 g were recorded in the fruits those were sprayed

with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6), respectively and

these were at par with the fruits of T2 (salicylic acid @ 8 mM) and T5 (methyl jasmonate

@ 4 mM). While lower amounts of total carotenoids (12.14 mg/100 g) were noted in the




and 14.63 mg/100, respectively. The interaction between treatments (SA and MeJA) and

storage periods showed that higher total carotenoids contents of 16.75 and 16.68 mg/100

g were recorded in the fruits those were sprayed with salicylic acid @ 12 mM (T3) and

methyl jasmonate @ 5 mM (T6) when analysed 30 days after storage, respectively and

these were at par with the fruits of T2 (salicylic acid @ 8 mM), T5 (methyl jasmonate @ 4

mM) and T3 (salicylic acid @ 12 mM) when analysed 30 and 60 days after storage,

respectively. Whereas, lower total carotenoids contents (8.77 mg/100 g) were noted in the

control fruits (To) when analysed 90 days after storage.

231










jasmonate (MeJA) on total carotenoids contents (mg/100 g)







0

10

20

30

40

50

60

70



TF

C (

mg

CE

Q/1

00

g)


0

2

4

6

8

10

12

14

16

18



To

tal

caro

ten

oid

s (m

g/1

00 g

)


232


Total limonin contents showed statistically significant differences (P≤0.05) regarding the

effects of treatments (SA and MeJA), storage periods and their interaction in the fruits of

Ray Ruby (Figure 4.180a). Lower amounts of total limonin contents (11.95 and 12.04

µg/mL) were recorded in the fruits those were sprayed with salicylic acid @ 12 mM (T3)

and methyl jasmonate @ 5 mM (T6), respectively. While higher amounts of total limonin

contents (14.34 µg/mL) were noted in the fruits those were untreated (To). The fruits

those were analysed 30 days after storage showed higher amounts total limonin contents

(14.11 µg/mL) as compared to the fruits those were analysed 60 and 90 days after storage

where total limonin contents were 12.80 and 11.48 µg/mL, respectively. The interaction

between treatments (SA and MeJA) and storage periods showed that lower total limonin

contents of 10.07 and 10.15 µg/mL were recorded in the fruits those were sprayed with

salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) when analysed 90 days

after storage, respectively and these were at par with each other. Whereas, higher amounts

of total limonin contents (14.51 and 14.38 µg/mL) were noted in the fruits of To (control)

and T4 (methyl jasmonate @ 3 mM) and when analysed 30 days after storage,

respectively and these were at par with each other (Figure 4.182


jasmonate (MeJA) on total limonin contents (µg/mL) during


To=control, T1=salicylic acid @ 6 mM, T2=salicylic acid @ 8

mM, T3=salicylic acid @ 12 mM, T4=methyl jasmonate @ 3 mM,




0

2

4

6

8

10

12

14

16



TL

C (

µg

/mL

)


233




treatments (SA and MeJA) and storage periods while their interaction was found non-

significant (Figure 4.183a). Minimum chilling injury indexes of 0.11, 0.11, 0.22 and

0.22% were recorded in the fruits of T6 (methyl jasmonate @ 5 mM), T3 (salicylic acid @

12 mM), T5 (methyl jasmonate @ 4 mM) and T2 (salicylic acid @ 8 mM), respectively

and these were at par with each other. While fruits those were untreated (To) showed

higher index (3.66%) of chilling injury in the fruits. The fruits those were analysed 90

days after storage showed higher index of chilling injury (1.57%) than the fruits those

were analysed 60 and 30 days after storage where chilling injury indexes were 0.90 and

0.66%, respectively and these were at par with each other.

4.5.1.3.2a Fruit rot (%)

The effects of treatments (SA and MeJA), storage periods and interaction between them

showed statistically significant differences (P≤0.05) regarding the fruit rot (Figure

4.184a). Lower indexes of fruit rot (0.88, 0.88, 1.44 and 1.44%) were recorded in the

fruits those were sprayed with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM

(T6), methyl jasmonate @ 4 mM (T5) and salicylic acid @ 8 mM (T2), respectively and

these were at par with each other. While higher index of fruit rot (9.66%) was noted in the


showed higher index of fruit rot (4.23%) than the fruits those were analysed 60 and 30


interaction between treatments (SA and MeJA) and storage periods showed that fruits

those were sprayed with methyl jasmonate @ 5 mM (T6), methyl jasmonate @ 4 mM

(T5), salicylic acid @ 12 mM (T3) and salicylic acid @ 8 mM (T2) showed zero index of

fruit rot when analysed 30 days after storage, respectively and these were at par with each

other. Whereas, higher index of fruit rot (13.66%) was noted in the control fruits (To)

when analysed 90 days after storage.

234


jasmonate (MeJA) on chilling injury (%) during storage (8oC) in








jasmonate (MeJA) on fruit rot (%) during storage (8oC) in the

fruits of Ray Ruby.





Each vertical bar represents mean of three replicates ± S

0

1

2

3

4

5

6



Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 day = 0%

0

2

4

6

8

10

12

14

16



Fru

it r

ot

(%)

Fruit rot at 0 day = 0%

235


The analysed data presented in Figure 4.185a showed significant differences at P≤0.05

regarding the effects of treatments (SA and MeJA), storage periods and their interaction.

Fruits those were sprayed with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM

(T6) and salicylic acid @ 8 mM (T2) showed lower losses in weights of 2.22, 2.66 and

2.77%, respectively and these were at par with each other. While higher loss in weight

(11.00%) was noted in the fruits those were untreated (To). The fruits those were analysed

90 days after storage showed higher loss in weight of 6.28% than the fruits those were

analysed 60 and 30 days after storage where losses in weights were 4.33 and 2.80%,


showed that lower losses in weights (1.33, 1.66, 1.66, 2.00 and 2.00%) were recorded in

the fruits of T3 (salicylic acid @ 12 mM), T6 (methyl jasmonate @ 5 mM), T2 (salicylic

acid @ 8 mM), T3 (salicylic acid @ 12 mM) and T5 (methyl jasmonate @ 4 mM) when

analysed 30, 30, 30, 60 and 30 days after storage, respectively and these were at par with

each other. Whereas, fruits those were untreated (To) showed higher loss in weight of

15.33% when analysed 90 days after storage.



fruits of Ray Ruby.






0

2

4

6

8

10

12

14

16

18



Weig

ht

loss

(%

)


236




statistically significant differences (P≤0.05) regarding the fruit color score (Figure

4.186a). Higher color scores (6.66 and 6.44) marked by the panellists were recorded in

the fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @

5 mM (T6). While minimum color score of 2.44 liked by the panellists was noted in the


showed higher color score of 6.33 ranked by the panellists than the fruits those were

analysed 60 and 30 days after storage where fruit color scores were 4.80 and 3.23,


showed that fruits those were sprayed with methyl jasmonate @ 5 mM (T6), salicylic acid

@ 12 mM (T3), salicylic acid @ 8 mM (T2) and methyl jasmonate @ 4 mM (T5) showed

higher color scores of 8.66, 8.33, 7.66 and 7.66 were rated by the panellists when

analysed 90 days after storage, respectively and these were at par with each other.

Whereas, minimum color scores (1.66, 2.00, 2.33 and 2.66) were liked by the panellists

for the fruits of To (control), T1 (salicylic acid @ 6 mM), T4 (methyl jasmonate @ 3 mM)

and To (control) when analysed 30 and 60 days after storage, respectively and these were

at par with each other.

4.5.1.4.2 Texture score

Statistically significant differences were found at P≤0.05 regarding the effects of

treatments (SA and MeJA) and storage periods while interaction between them showed

non-significant results for texture score (Figure 4.187a). The fruits those were sprayed

with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM (T6) and salicylic acid @ 8

mM (T2) showed higher color scores of 7.88, 7.66 and 7.33 were marked by the

panellists, respectively and these were at par with each other. While minimum texture

score of 3.88 was liked by the panellists in the fruits those were untreated (To). The fruits

those were analysed 30 days after storage showed higher texture score of 7.28 ranked by

the panellists as compared to the fruits those were analysed 60 and 90 days after storage

where color scores were 6.57 and 5.61, respectively.

237


jasmonate (MeJA) on color score during storage (8oC) in the

fruits of Ray Ruby.







jasmonate (MeJA) on texture score during storage (8oC) in the

fruits of Ray Ruby.






0

1

2

3

4

5

6

7

8

9

10



Co

lor s

core


0

1

2

3

4

5

6

7

8

9

10



Textu

re s

co

re


238


The analysed data presented in Figure 4.88a showed statistically significant differences at

P≤0.05 regarding the effects of treatments (SA and MeJA), storage periods and their

interaction for taste score (Figure 4.188a). The fruits those were sprayed with salicylic

acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed higher taste scores of

7.00, 7.00 were marked by the panellists, respectively and these were at par with each

other. While minimum taste score of 3.88 was liked by the panellists in the fruits those

were untreated (To). The fruits those were analysed 90 days after storage showed higher

taste score of 6.66 ranked by the panellists as compared to the fruits those were analysed

60 and 30 days after storage where taste scores were 5.90 and 5.33, respectively. The


those were sprayed with methyl jasmonate @ 5 mM (T6) and salicylic acid @ 12 mM

(T3) showed higher taste scores of 8.33 and 8.33, respectively when analysed 90 days

after storage and these were at par with the fruits of T5 (methyl jasmonate @ 4 mM) and

T2 (salicylic acid @ 8 mM) when analysed 90 days after storage, respectively. Whereas,

minimum taste score of 2.33 was marked by the panellists in the control fruits (To) when

analysed 90 days after storage.




non-significant results for sourness score (Figure 4.189a). The fruits those were sprayed

with methyl jasmonate @ 5 mM (T6) and salicylic acid @ 12 mM (T3) showed higher

sourness scores of 7.44 and 7.22 were marked by the panellists, respectively and these

were at par with each other. While minimum sourness scores of 5.11, 5.55 and 5.66 were

liked by the panellists in the control fruits (To), T1 (salicylic acid @ 6 mM) and T4

(methyl jasmonate @ 3 mM), respectively and these were at par with each other. The

fruits those were analysed 90 days after storage showed higher sourness score of 7.14

ranked by the panellists as compared to the fruits those were analysed 60 and 30 days

after storage where sourness scores were 6.28 and 5.52, respectively.

239


jasmonate (MeJA) on taste score during storage (8oC) in the

fruits of Ray Ruby.








fruits of Ray Ruby.






0

1

2

3

4

5

6

7

8

9

10



Tast

e s

co

re


0

1

2

3

4

5

6

7

8

9

10



So

urn

ess

sco

re


240



significant differences at P≤0.05 for sweetness score (Figure 4.190a). Higher sweetness

scores of 7.33, 7.22, 6.77 and 6.77 were marked by the panellists in the fruits of T6

(methyl jasmonate @ 5 mM), T3 (salicylic acid @ 12 mM), T2 (salicylic acid @ 8 mM)

and T5 (methyl jasmonate @ 4 mM), respectively and these were at par with each other.

While minimum sweetness score of 3.55 was liked by the panellists in the fruits those


sweetness score of 6.95 ranked by the panellists as compared to the fruits those were

analysed 60 and 30 days after storage where sweetness scores were 6.19 and 5.00,


showed that fruits those were sprayed with methyl jasmonate @ 5 mM (T6) and salicylic

acid @ 12 mM (T3) showed higher sweetness scores of 8.66 and 8.66, respectively when

analysed 30 days after storage and these were at par with the fruits of T2 (salicylic acid @

8 mM), T5 (methyl jasmonate @ 4 mM), T6 (methyl jasmonate @ 5 mM) and T3

(salicylic acid @ 12 mM) when analysed 90, 90, 60 and 60 days after storage,

respectively. Whereas, minimum sweetness score of 3.00 was marked by the panellists in

the control fruits (To) when analysed 90 days after storage and these were at par with the

fruits of To (control) and T4 (methyl jasmonate @ 3 mM) when analysed 60 and 30 days

after storage, respectively (Figure 4.190a).

241



fruits of Ray Ruby.







Overall quality score showed significant differences at P≤0.05 regarding the effects of

treatments (SA and MeJA), storage periods and their interaction (4.191a). Maximum

overall quality scores of 7.33, 7.22, 6.66 and 6.66 were marked by the panellists in the

fruits of T3 (salicylic acid @ 12 mM), T6 (methyl jasmonate @ 5 mM), T2 (salicylic acid

@ 8 mM) and T5 (methyl jasmonate @ 4 mM), respectively and these were at par with

each other. While minimum overall quality score of 3.22 was liked by the panellists in the


showed higher overall quality score of 6.80 was ranked by the panellists as compared to

the fruits those were analysed 60 and 30 days after storage where overall quality scores

were 5.95 and 5.04, respectively. The interaction between treatments (SA and MeJA) and

storage periods showed that fruits those were sprayed with salicylic acid @ 12 mM (T3)

and methyl jasmonate @ 5 mM (T6) showed higher overall quality scores of 8.33 and

8.33, respectively when analysed 90 days after storage and these were at par with the

fruits of T2 (salicylic acid @ 8 mM), T5 (methyl jasmonate @ 4 mM), T3 (salicylic acid

@ 12 mM) and T6 (methyl jasmonate @ 5 mM) when analysed 90, 90, 30 and 30 days

after storage, respectively. Whereas, minimum overall quality score of 2.66 was marked

0

1

2

3

4

5

6

7

8

9

10


Sw

eetn

ess

sco

re


242

by the panellists in the control fruits (To) when analysed 90 days after storage and these

were at par with the fruits of To (control) when analysed 60 and 30 days after storage,

respectively.


jasmonate (MeJA) on overall quality score during storage (8oC)

in the fruits of Ray Ruby.


T3=salicylic acid @ 12 mM, T4=methyl jasmonate @ 3 mM, T5=methyl jasmonate @ 4 mM, T6=methyl jasmonate @ 5 mM



0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Overall quality score at 0 day = 3.11

243

4.5. Experiment-1 (b) Effects of pre-harvest spray of salicylic (SA) and

Methyl Jasmonate (MeJA) on the chilling

injury, decay and phytochemicals during the

storage in grapefruit Cv. Shamber

Results 4.5.1b




at P≤0.05 regarding the effects of treatments (SA and MeJA) and storage periods while

interaction between them was found non-significant for pH in the fruits of Shamber. The

fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5

mM (T6) showed higher values of pH (5.51 and 5.43), respectively and these were

statistically at par with each other as compared to the fruits of other treatments. While

lower pH values of 4.52, 4.56 and 4.61 were recorded in the fruits of To (control), T4

(methyl jasmonate @ 3 mM) and T1 (salicylic acid @ 6 mM), respectively and these were

at par with each other. The fruits those were analysed 90 days after storage showed higher

pH of 5.25 than the fruits those were analysed 60 and 30 days after storage where pH

values were 5.06 and 4.77, respectively.



treatments (SA and MeJA), storage periods and their interaction on total soluble solids

(TSS) in the fruits of Shamber (Figure 4.193b). Higher TSS values (6.17 and 6.09 oBrix)

were noted in the fruits of T3 (salicylic acid @ 12 mM) and T6 (methyl jasmonate @ 5

mM), respectively and these were at par with each other. While lower TSS values of 5.28

and 5.39 oBrix were recorded in the fruits of To (control) and T4 (methyl jasmonate @ 3

mM), respectively and these were at par with each other. The fruits those were analysed

90 days after storage showed higher TSS of 6.01 oBrix as compared to the fruits those

were analysed 60 and 30 days after storage where TSS contents were 5.69 and 5.50 oBrix,


showed that higher TSS values of 6.63 and 6.54 oBrix were recorded in the fruits those

were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6)

when analysed 90 days after storage, respectively and these were at par with each other.

Whereas, lower TSS value 5.09 oBrix was noted in the control fruits (To) when analysed

30 days after storage.

244

Figure 4.192 b Effects of pre-harvest spray of salicylic acid (SA) and methyl


Shamber.






Figure 4.193b Effects of pre-harvest spray of salicylic acid (SA) and methyl

jasmonate (MeJA) on TSS (oBrix) during storage (8

oC) in the

fruits of Shamber.






0

1

2

3

4

5

6

7



pH

pH at 0 day= 3.78

0

1

2

3

4

5

6

7

8



TS

S (

oB

rix

)

TSS at 0 day= 4.67 oBrix

245



significant differences (P≤0.05) while interaction between them was found non-

significant for total titratable acidity (Figure 4.194b). The fruits those were sprayed with

salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed lower titratable

acidity of 1.24 and 1.31%, respectively and these were statistically at par with each other

as compared to the fruits of other treatments. While higher titratable acidity of 1.64% was

recorded in the control fruits (To). The fruits those were analysed 30 days after storage

showed higher titratable acidity of 1.53% than the fruits those were analysed 60 and 90

days after storage where titratable acidity values were 1.43 and 1.33%, respectively.



treatments (SA and MeJA), storage periods and their interaction on TSS/acidity ratio in

the fruits of Shamber (Figure 4.195b). Fruits those were sprayed with salicylic acid @ 12

mM (T3) showed higher TSS/acidity of 4.99 as compared to the fruits of other treatments

while lower TSS/acidity (3.23) was recorded in the fruits those were untreated (To). The

fruits those were analysed 90 days after storage showed higher TSS/acidity of 4.57 than

the fruits those were analysed 60 and 30 days after storage where TSS/acidity values were

4.02 and 3.64, respectively. The interaction between treatments (SA and MeJA) and

storage periods showed that higher TSS/acidity values of 5.82 and 5.38 were recorded in

the fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @

5 mM (T6) when analysed 90 days after storage, respectively. Whereas, lower TSS/acidity

of 2.89 was noted in the control fruits (To) when analysed 30 days after storage and these

were at par with the fruits of T1 (salicylic acid @ 6 mM) and To (control) when analysed

30 and 60 days after storage, respectively.

246










jasmonate (MeJA) on TSS/acidity ratio during storage (8oC) in







0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2



Acid

ity (

%)

Acidity at 0 day= 1.97%

0

1

2

3

4

5

6

7



TS

S/a

cid

ity

TSS/acidity at 0 day= 2.66

247



statistically significant differences at P≤0.05 on ascorbic acid contents (Figure 4.196b).

Fruits those were sprayed with salicylic acid @ 12 mM (T3) showed higher ascorbic acid

contents of 39.17 mg/100 g and these were at par with the fruits of T6 (methyl jasmonate

@ 5 mM), T2 (salicylic acid @ 8 mM) and T5 (methyl jasmonate @ 4 mM), respectively.

While, lower ascorbic acid contents of 34.16 mg/100 g were noted in the control fruits

(To). The fruits those were analysed 30 days after storage showed higher ascorbic acid

contents of 39.17 mg/100 g as compared to the fruits those were analysed 60 and 90 days

after storage where ascorbic acid contents were 37.67 and 36.20 mg/100 g, respectively.

The interaction between treatments (SA and MeJA) and storage periods showed that

higher ascorbic acid contents of 39.80 mg/100 g were recorded in the fruits those were

sprayed with salicylic acid @ 12 mM (T3) when analysed 30 days after storage and these

were at par with the fruits of T6 (methyl jasmonate @ 5 mM), T2 (salicylic acid @ 8

mM), T5 (methyl jasmonate @ 4 mM) and T3 (salicylic acid @ 12 mM) when analysed 60

and 90 days after storage, respectively. Whereas, lower ascorbic acid contents of 30.99

mg/100 g were noted in the control fruits (To) when analysed 90 days after storage.







(DAS=days after storage). Each vertical bar represents mean of

three replicates ± S.E

0

5

10

15

20

25

30

35

40

45



Asc

orb

ic a

cid

(m

g/1

00 g

)

Ascorbic acid at 0 day= 38.32 mg/100 g

248



significant differences (P≤0.05) while their interaction was found non-significant for total

sugar contents (Figure 4.197a). The fruits those were sprayed with salicylic acid @ 12

mM (T3) and methyl jasmonate @ 5 mM (T6) showed higher total sugar contents of 6.31

and 6.18%, respectively as compared to the fruits of other treatments. While lower total

sugar contents of 5.29% were recorded in the control fruits (To). The fruits those were

analysed 90 days after storage showed higher total sugar contents (6.18%) than the fruits

those were analysed 60 and 30 days after storage where total sugar contents were 5.86

and 5.32%, respectively. (Figure 4.197b.


jasmonate (MeJA) on total sugar contents (%) during storage









regarding the treatments (SA and MeJA) and storage periods while interaction between

them was found non-significant for reducing sugar contents. The fruits those were

sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed

0

1

2

3

4

5

6

7

8



To

tal

sug

ar s

(%

)

Total sugars at 0 day= 4.55%

249

higher reducing sugar contents of 4.05 and 3.96%, respectively and these were at par with

each other. While lower reducing sugar contents (3.42 and 3.51%) were recorded in the

fruits of To (control) and T4 (methyl jasmonate @ 3 mM), respectively and these were at

par with each other. The fruits those were analysed 90 days after storage showed higher

reducing sugar contents (3.90%) than the fruits those were analysed 60 and 30 days after

storage where reducing sugar contents were 3.74 and 3.54%, respectively.



treatments and storage periods while interaction between them was found non-significant

for non-reducing sugar contents (Figure 4.199a). The fruits those were sprayed with

salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM (T6) and salicylic acid @ 8 mM

(T2) showed higher non-reducing sugar contents (2.26, 2.21 and 2.12%), respectively and

these were at par with each other. While, lower non-reducing sugar contents of 1.87%

were noted in the control fruits (To) and these were at par with the fruits of T1 (salicylic

acid @ 6 mM) and T4 (methyl jasmonate @ 3 mM). The fruits those were analysed 90

days after storage showed higher non-reducing sugar contents (2.27%) as compared to the

fruits those were analysed 60 and 30 days after storage where non-reducing sugars were


250


jasmonate (MeJA) on reducing sugar contents (%) during















0

0.5

1

1.5

2

2.5

3

3.5

4

4.5



Red

ucin

g s

ug

ars

(%)

Reducing sugars at 0 day= 3.11%

0

0.5

1

1.5

2

2.5

3



No

n-r

ed

ucin

g s

ug

ars

(%)

Non-reducing sugars at 0 day= 1.73%

251



Total phenolic contents (TPC) showed significant differences (P≤0.05) regarding the

effects of treatments (SA and MeJA) and storage periods while their interaction was

found non-significant (Figure 4.200b). The fruits those were sprayed with salicylic acid

@ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed higher total phenolic contents

of 170.48 and 167.28 mg GAE/100 g as compared to the fruits of all other treatments.

While lower total phenolic contents of 142.82 mg GAE/100 g were recorded in the

control fruits (To). The fruits those were analysed 30 days after storage showed higher

total phenolic contents (165.28 mg GAE/100 g) than the fruits those were analysed 60

and 90 days after storage where total phenolic contents were 157.17 and 151.75 mg

GAE/100 g, respectively.

4.5.1.2.2b Total antioxidants activities (% DPPH inhibition)


treatments (SA and MeJA), storage periods and their interaction on total antioxidants

activities in the fruits of Shamber (Figure 4.201b). Higher total antioxidants activities

(75.34 and 74.21%) were recorded in the fruits of T3 (salicylic acid @ 12 mM) and T6

(methyl jasmonate @ 5 mM), respectively and these were at par with each other. While

lower antioxidants activities of 54.76% were noted in the fruits those were untreated (To).

The fruits those were analysed 30 days after storage showed higher total antioxidants

activities (73.91%) as compared to the fruits those were analysed 60 and 90 days after



antioxidants activities of 81.08 and 80.07% were recorded in the fruits those were sprayed

with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) when analysed 30

days after storage, respectively and these were at par with each other. Whereas, lower

antioxidants activities of 42.62% were noted in the control fruits (To) when analysed 90

days after storage.

252










jasmonate (MeJA) on total antioxidants activities (%DPPH

inhibition) during storage (8oC) in the fruits of Shamber.






0

20

40

60

80

100

120

140

160

180

200



TP

C (

mg

GA

E/1

00

g)

TPC at 0 day= 167.32 mg GAE/100 g

0

10

20

30

40

50

60

70

80

90



%D

PP

H i

nh

ibit

ion

TAA at 0 day= 71.23%

253



(P≤0.05) regarding the effects of treatments (SA and MeJA), storage periods and their

interaction on total flavonoids contents (TFC) in the fruits. Higher amounts of TFC

(58.30 and 56.04 mg CEQ/100 g) were recorded in the fruits of T3 (salicylic acid @ 12

mM) and T6 (methyl jasmonate @ 5 mM), respectively as compared to the fruits of other

treatments. While, lower TFC of 41.04 mg CEQ/100 g were noted in the fruits those were

untreated (To). The fruits those were analysed 30 days after storage showed higher TFC

value (57.00 mg CEQ/100 g) than the fruits those were analysed 60 and 90 days after

storage where TFC values were 50.83 and 44.96 mg CEQ/100 g, respectively. The


amounts of TFC (62.66 and 60.69 mg CEQ/100 g) were recorded in the fruits those were

sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) when

analysed 30 days after storage, respectively. While, lower amounts of TFC (31.91 mg

CEQ/100 g) were noted in the control fruits (To) when analysed 90 days after storage.









0

10

20

30

40

50

60

70



TF

C (m

g C

EQ

/10

0 g

)

TFC at 0 day= 55.43 mg CEQ/100 g

254



treatments (SA and MeJA), storage periods and their interaction on total carotenoids

contents in the fruits of Shamber (Figure 4.203b). Higher amounts of total carotenoids

contents of 18.09% and 18.03 mg/100 g were recorded in the fruits those were sprayed

with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6), respectively and

these were at par with the fruits of T5 (methyl jasmonate @ 4 mM) and T2 (salicylic acid

@ 8 mM). While, lower amounts of total carotenoids (13.82 mg/100 g) were noted in the




and 16.33 mg/100, respectively. The interaction between treatments (SA and MeJA) and

storage periods showed that higher total carotenoids contents of 18.46 and 18.41 mg/100

g were recorded in the fruits those were sprayed with salicylic acid @ 12 mM (T3) and

methyl jasmonate @ 5 mM (T6) when analysed 30 days after storage, respectively and

these were at par with the fruits of T2 (salicylic acid @ 8 mM), T5 (methyl jasmonate @ 4

mM) and T3 (salicylic acid @ 12 mM) when analysed 30 and 60 days after storage,

respectively. Whereas, lower total carotenoids contents (10.61 mg/100 g) were noted in

the control fruits (To) when analysed 90 days after storage.

255


jasmonate (MeJA) on total carotenoids contents (mg/100 g)








Total limonin contents showed statistically significant differences (P≤0.05) regarding the

effects of treatments (SA and MeJA), storage periods and their interaction in the fruits of

Shamber (Figure 4.204b). Lower amounts of total limonin contents (10.66 and 10.78

µg/mL) were recorded in the fruits those were sprayed with salicylic acid @ 12 mM (T3)

and methyl jasmonate @ 5 mM (T6), respectively and these were at par with each other.

While higher amounts of total limonin contents (13.05 µg/mL) were noted in the fruits

those were untreated (To). The fruits those were analysed 30 days after storage showed

higher amounts total limonin contents (12.82 µg/mL) as compared to the fruits those were

analysed 60 and 90 days after storage where total limonin contents were 11.47 and 10.28

µg/mL, respectively. The interaction between treatments (SA and MeJA) and storage

periods showed that lower total limonin contents of 8.91 and 9.10 µg/mL were recorded

in the fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl jasmonate

@ 5 mM (T6) when analysed 90 days after storage, respectively and these were at par

with each other. Whereas, higher amounts of total limonin contents (13.33 µg/mL) were

noted in the untreated fruits (To) and these were at par with the fruits of T4 (methyl

0

2

4

6

8

10

12

14

16

18

20



To

tal

caro

ten

oid

s (m

g/1

00 g

)

TC at 0 day= 19.32 mg/100 g

256

jasmonate @ 3 mM), T1 (salicylic acid @ 6 mM) and To (control) when analysed 30 and

60 days after storage, respectively.


jasmonate (MeJA) on Total limonin contents (µg/mL) during










treatments (SA and MeJA) and storage periods while their interaction was found non-

significant (Figure 4.205b). Minimum chilling injury indexes of 0.11, 0.11, 0.11 and

0.22% were recorded in the fruits of T6 (methyl jasmonate @ 5 mM), T3 (salicylic acid @

12 mM), T5 (methyl jasmonate @ 4 mM) and T2 (salicylic acid @ 8 mM), respectively

and these were at par with each other. While fruits those were untreated (To) showed

higher index (3.33%) of chilling injury in the fruits. The fruits those were analysed 90

days after storage showed higher index of chilling injury (1.42%) than the fruits those

were analysed 60 and 30 days after storage where chilling injury indexes were 0.85 and

0.57%, respectively and these were at par with each other.

0

2

4

6

8

10

12

14

16



TL

C (

µg

/mL

)


257

4.5.1.3.2b. Fruit rot (%)

The effects of treatments (SA and MeJA), storage periods and interaction between them

showed statistically significant differences (P≤0.05) regarding the fruit rot (Figure

4.206b). Lower indexes of fruit rot (0.77, 0.88, 1.33 and 1.33%) were recorded in the

fruits those were sprayed with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM

(T6), methyl jasmonate @ 4 mM (T5) and salicylic acid @ 8 mM (T2), respectively and

these were at par with each other. While higher index of fruit rot (9.22%) was noted in the


showed higher index of fruit rot (3.90%) than the fruits those were analysed 60 and 30



those were sprayed with methyl jasmonate @ 5 mM (T6), methyl jasmonate @ 4 mM

(T5), salicylic acid @ 12 mM (T3) and salicylic acid @ 8 mM (T2) showed zero index of

fruit rot when analysed 30 days after storage, respectively and these were at par with the

fruits of T6 (methyl jasmonate @ 5 mM) and T3 (salicylic acid @ 12 mM) when analysed

60 days after storage. Whereas, higher index of fruit rot (13.00%) was noted in the control

fruits (To) when analysed 90 days after storage.


jasmonate (MeJA) on chilling injury (%) during storage (8oC) in







0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5



Ch

illi

ng i

nju

ry (

%)

Chilling injury at 0 day= 0%

258

Figure 4.206 Effects of pre-harvest spray of salicylic acid (SA) and methyl

jasmonate (MeJA) on chilling fruit rot (%) during storage (8oC)


To=control, T1=salicylic acid @ 6mM, T2=salicylic acid @ 8 mM,



(DAS=days after storage). Each vertical bar represents mean of

three replicates ± S.E.


The analysed data presented in Figure 4.207 b showed significant differences at P≤0.05

regarding the effects of treatments (SA and MeJA), storage periods and their interaction.

Fruits those were sprayed with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM

(T6), salicylic acid @ 8 mM (T2) and methyl jasmonate @ 4 mM (T5) showed lower

losses in weights of 2.11, 2.66, 2.66 and 3.00%, respectively and these were at par with

each other. While higher loss in weight (10.33%) was noted in the fruits those were

untreated (To). The fruits those were analysed 90 days after storage showed higher loss in

weight of 5.85% than the fruits those were analysed 60 and 30 days after storage where

losses in weights were 4.23 and 2.66%, respectively. The interaction between treatments

(SA and MeJA) and storage periods showed that lower losses in weights (1.33 and

1.66%) were recorded in the fruits of T3 (salicylic acid @ 12 mM), T6 (methyl jasmonate

@ 5 mM), respectively when analysed 30 days after storage and these were at par with

the fruits of T2 (salicylic acid @ 8 mM), T3 (salicylic acid @ 12 mM), T5 (methyl

jasmonate @ 4 mM), T6 (methyl jasmonate @ 5 mM), T2 (salicylic acid @ 8 mM), T1

0

2

4

6

8

10

12

14

16



Fru

it r

ot

(%)


259

(salicylic acid @ 6 mM), T3 (salicylic acid @ 12 mM), T5 (methyl jasmonate @ 4 mM)

and T4 (methyl jasmonate @ 3 mM) when analysed 30, 60, 30, 60, 60, 30, 90, 60 and 30

days after storage, respectively and these were at par with each other. Whereas, fruits

those were untreated (To) showed higher loss in weight of 14.00% when analysed 90 days

after storage.



fruits of Shamber.









significant differences (P≤0.05) while their interaction was found non-significant

regarding the fruit color score (Figure 4.208b). Higher color scores (6.88 and 6.66)

marked by the panellists were recorded in the fruits those were sprayed with salicylic acid

@ 12 mM (T3) and methyl jasmonate @ 5 mM (T6). While minimum color score of 2.66

liked by the panellists was noted in the fruits those were untreated (To). The fruits those

were analysed 90 days after storage showed higher color score of 6.61 ranked by the

panellists than the fruits those were analysed 60 and 30 days after storage where fruit

color scores were 5.09 and 3.57, respectively.

0

2

4

6

8

10

12

14

16



Weig

ht

loss

(%

)

Weight loss at 0 day= 0%

260




non-significant results for texture score (Figure 4.209b). The fruits those were sprayed

with salicylic acid @ 12 mM (T3), methyl jasmonate @ 5 mM (T6) and salicylic acid @ 8

mM (T2) showed higher color scores of 8.11, 7.66 and 8.00 were marked by the

panellists, respectively and these were at par with each other. While minimum texture

score of 4.33 was liked by the panellists in the fruits those were untreated (To). The fruits

those were analysed 30 days after storage showed higher texture score of 7.52 ranked by

the panellists as compared to the fruits those were analysed 60 and 90 days after storage

where texture scores were 6.66 and 5.95, respectively.


jasmonate (MeJA) on color score during storage (8oC) in the

fruits of Shamber.






0

1

2

3

4

5

6

7

8

9

10



Co

lor s

core

Color score at 0 day= 3.77

261


jasmonate (MeJA) on texture score during storage (8oC) in the

fruits of Shamber.








at P≤0.05 regarding the effects of treatments (SA and MeJA), storage periods and their

interaction on taste score. The fruits those were sprayed with salicylic acid @ 12 mM (T3)

and methyl jasmonate @ 5 mM (T6) showed higher taste scores of 7.33, 7.33 were

marked by the panellists, respectively and these were at par with the fruits of T2 (salicylic

acid @ 8 mM) and T5 (methyl jasmonate @ 4 mM). While minimum taste score of 4.22

was liked by the panellists in the fruits those were untreated (To). The fruits those were

analysed 90 days after storage showed higher taste score of 6.95 ranked by the panellists

as compared to the fruits those were analysed 60 and 30 days after storage where taste

scores were 6.23 and 5.80, respectively and these were at par with each other. The


those were sprayed with methyl jasmonate @ 5 mM (T6) and salicylic acid @ 12 mM

(T3) showed higher taste scores of 8.66 and 8.66, respectively when analysed 90 days

after storage and these were at par with the fruits of T2 (salicylic acid @ 8 mM) and T5

(methyl jasmonate @ 4 mM) when analysed 90 days after storage, respectively. Whereas,

0

1

2

3

4

5

6

7

8

9

10



Textu

re s

co

re

Texture score at 0 day= 5.44

262

minimum taste score of 2.66 was marked by the panellists in the control fruits (To) when

analysed 90 days after storage.




non-significant results for sourness score (Figure 4.211b). The fruits those were sprayed

with methyl jasmonate @ 5 mM (T6) and salicylic acid @ 12 mM (T3) showed higher

sourness scores of 7.77 and 7.44 were marked by the panellists, respectively and these

were at par with each other. While minimum sourness scores of 5.33 and 5.77 were liked

by the panellists in the control fruits (To) and these were at par with each other. The fruits

those were analysed 90 days after storage showed higher sourness score of 7.33 was

ranked by the panellists as compared to the fruits those were analysed 60 and 30 days

after storage where sourness scores were 6.66 and 5.80, respectively.


jasmonate (MeJA) on taste score during storage (8oC) in the

fruits of Shamber.

To=control, T1 =salicylic acid @ 6 mM, T2=salicylic acid @ 8 mM,





0

1

2

3

4

5

6

7

8

9

10



Tast

e s

co

re


263



fruits of Shamber.








significant differences at p≤0.05 for sweetness score (Figure 4.212b). Higher sweetness

scores of 7.44, 7.44, 7.11 and 7.11 were marked by the panellists in the fruits of T6

(methyl jasmonate @ 5 mM), T3 (salicylic acid @ 12 mM), T2 (salicylic acid @ 8 mM)

and T5 (methyl jasmonate @ 4 mM), respectively and these were at par with each other.

While minimum sweetness score of 3.88 was liked by the panellists in the fruits those


sweetness score of 7.23 ranked by the panellists as compared to the fruits those were

analysed 60 and 30 days after storage where sweetness scores were 6.42 and 5.33,


showed that fruits those were sprayed with salicylic acid @ 12 mM (T3) and methyl

jasmonate @ 5 mM (T6) showed higher sweetness scores of 8.66 and 8.66, respectively

when analysed 90 days after storage and these were at par with the fruits of T2 (salicylic

acid @ 8 mM), T5 (methyl jasmonate @ 4 mM), T3 (salicylic acid @ 12 mM) and T6

(methyl jasmonate @ 5 mM) when analysed 90, 90, 60 and 60 days after storage,

respectively. Whereas, minimum sweetness score of 3.33 was marked by the panellists in

0

1

2

3

4

5

6

7

8

9

10



So

urn

ess

sco

re

Sourness score at 0 day= 4.11

264

the control fruits (To) when analysed 90 days after storage and these were at par with the

fruits of To (control) and T4 (methyl jasmonate @ 3 mM) when analysed 60 and 30 days

after storage, respectively.


Overall quality score showed significant differences at P≤0.05 regarding the effects of

treatments (SA and MeJA), storage periods and their interaction (4.213b). Maximum

overall quality scores of 7.66 and 7.44 were marked by the panellists in the fruits of T3

(salicylic acid @ 12 mM) and T6 (methyl jasmonate @ 5 mM), respectively and these

were at par with each other. While minimum overall quality score of 3.66 was liked by

the panellists in the fruits those were untreated (To). The fruits those were analysed 90

days after storage showed higher overall quality score of 7.14 was ranked by the

panellists as compared to the fruits those were analysed 60 and 30 days after storage

where overall quality scores were 6.19 and 5.42, respectively. The interaction between

treatments (SA and MeJA) and storage periods showed that fruits those were sprayed

with salicylic acid @ 12 mM (T3) and methyl jasmonate @ 5 mM (T6) showed higher

overall quality scores of 8.66 and 8.66, respectively when analysed 90 days after storage

and these were at par with the fruits of T2 (salicylic acid @ 8 mM), T5 (methyl jasmonate

@ 4 mM), T3 (salicylic acid @ 12 mM) and T6 (methyl jasmonate @ 5 mM) when

analysed 90, 90, 30 and 30 days after storage, respectively. Whereas, minimum overall

quality scores of 3.00 and 3.33 were marked by the panellists in the control fruits (To)

when analyse 90 and 60 days after storage, respectively and these were at par with each

other.

265



fruits of Shamber.







jasmonate (MeJA) on overall quality score during storage (8oC)







0

1

2

3

4

5

6

7

8

9

10



Sw

eetn

ess

sco

re

Sweetness score at 0 day= 3.66

0

1

2

3

4

5

6

7

8

9

10



Overall

qu

ali

ty s

core

Overall quality score at 0 day= 3.88

266


The signalling molecules like salicylic acid (SA) and methyl jasmonate (MeJA)

are endogenous plant growth substances which can play a key role in plant growth and

development, and responses to environmental stresses. Salicylic acid is cosmically spread

in plant kingdom (Raskin et al., 1990) and is included in plant hormones group (Raskin,

1992).

The results indicated that the fruits treated with SA and Me JA showed better

performance in (TSS, Vit C, TS, RS, NRS and TSS/Acid) biochemical changes for both

gape fruit cultivars. This better performance may be due to the less losses of organic acid

and slow respiration change in treated fruits. It is because the gradual increase in pH of

juice which is correlated with the breakdown of organic acid due to respiration and

senescence. In an earlier study, Pesis et al. (1999) observed a decrease in titratable acidity

and increase in pH of fruit during the whole storage period in lemon fruit. In another

study, during prolonged storage lime fruits, pH was enhanced (Verma and Dashora,

2000). The previous findings also support the present results where it was observed that

mandarins stored for six months had higher levels of pH (Kays, 1991).

Total soluble solids are a key factor to judge the fruit quality. For determination of

fruit quality, SSC, titratable acidity, firmness, size and color are main criterion of

consumer for selection of any fruit (Hoehn et al., 2003; Lu and Chen, 2004). It is

understood that soluble solids concentration is increased during storage period as a result

of insoluble starch conversion into soluble solids. This change in soluble solids

concentration may be correlated with hydrolytic regulation of starch concentrations

during postharvest storage which ultimately results in starch conversion (breakdown) to

sugars (key fruit ripening indicator) (Kays, 1991). Our results indicate that higher

concentrations of SA @ 12 mM and MeJA @ 5 mM increased the levels of TSS in fruits

as compared to the fruits of control. Higher soluble solids in grapefruit are preferred by

consumer (Crisosto et al., 2003). Likewise, Peng and Jiang (2006) have documented that

SA pre-treatment to fresh-cut of Chinese water chestnut increased SSC, titratable acidity

and ascorbic acid. Similar results were also reported in a two year study, SSC in

strawberry fruits, was increased when plants were sprayed with SA than control (Karlidag

et al., 2009). In an early study, higher levels of SSC, good fruit firmness and titratable

acidity were recorded in SA treated banana fruits during ripening (Srivastava and

Dwivedi, 2000). Moreover, Increase in SSC was recorded in lime fruits treated with

MeJA than the control stored at same temperature regime (Tasneem, 2004). Fruit taste is

267

mainly made up of sugars and acids combination. Fruits with high acidity retain the flavor

of ripened fruit and applied SA and Me JA had no effects on acidity of grapefruit. Other

researchers have also reported that SA upheld the increased content of titratable acidity in

fresh-cut Chinese water (Ulrich, 1970). However, SA and MeJA treatments had non-

significant influence on TA of fruits over the storage time and similar results were also

reported by Sayyari et al. (2009) and Ranjbaran et al. (2011) in two separate studies.

Our study showed that there was consistent decrease in Vitamin C content of in all

treatments expect the higher doses of both chemicals. These findings are very much in

accordance with results of Akhtar et al. (2010) who reported that Vitamin C in loquat

fruits was reduced constantly to a great extent during ten weeks storage period. Higher

SA concentrations increased levels of Vitamin C content in grapefruit during the entire

storage period than lower concentrations and control. Control fruits showed lower AA

content which may be due to increased organic acids conversion to sugars. In another

study, Ruoyi et al. (2005) \described that treated peach fruits showed high levels of

Vitamin C content 50 days after storage. The applied SA on fresh-cut Chinese water

chestnut enhanced the AA contents compared to control (Peng and Jiang, 2006). In a

similar study, Karlidag et al. (2009) reported that strawberry plants repeatedly sprayed

with SA showed an enhancement in AA in fruits. Similarly, Kalarani et al. (2002)

observed that tomato fruits possessed higher AA concentrations when treated with SA.

This study revealed that total sugars and reducing sugars in general, were

increased with the advancement of storage period under all SA and MeJA concentrations.

However, SA and MeJA treated fruits had higher contents of total and reducing sugars

compared with control during the entire storage period. Control fruits showed increased

losses in total and reducing sugars contents all treatments increased total sugars and

reducing sugars content with the progress in storage period and reached to highest values

after 90 days of storage period. Although, SA and MeJA treatments had no significant

effects on non-reducing sugars content however, higher doses of both chemicals

concentrations resulted in higher levels of non-reducing sugars content than that of

control fruits. Untreated fruits showed losses in sucrose which may implicate negatively

by altering the expression genes associated with quality (King, 1989; Meena et al., 2001).

This study also revealed that non-reducing sugars showed fluttered trend during storage

period. Higher concentrations of both chemicals increased non reducing sugars than lower

concentrations and control. In summarized way, all treatments increased sugars content

grapefruits during storage period but this increase was concentration dependent. Fruit

268

quality status can be determined from the levels of SSC: TA ratio. In this study, SA and

MeJA concentrations significantly increased higher SSC: TA ratio compared with control

fruits during storage period. Untreated fruits (control) had lower levels of SSC: TA ratio

after 90 days of storage period. These higher levels of SSC: TA ratio may be attributed to

decrease concentrations of titratable acidity in SA treated fruits. In a previous study, it

was found that SA treated fruits of plum cultivars (Black Amber; Amber Jewel and

Angelino) showed higher SSC:TA ratio when compared with their respective control

(Khan and Singh, 2007). However, a number of researchers reported that SA treatment

showed significant effect on SSC in several fruits like grape (Ranjbaran et al., 2011) and

persimmon (Kader, 1991).

Maximum sweetness in both cultivars was measured during storage by application

of higher doses of SA and MeJA after storage which may be due to increase in sugars

content due to the activity of sucrose-phosphate synthase (Hubbard et al., 1991 Maximum

sweetness in both cultivars was measured during storage by application of higher doses of

SA and MeJA after storage which may be due to increase in sugars content due to the

activity of sucrose-phosphate synthase Serrano et al. (2005) and Malik and Singh (2005)

also reported the similar results in citrus. Taste of fruit is essentially because of soluble

solids content and acids ratio and is perceived by specialized taste buds on the tongue.

Different types of tastes exist however, there are four main prevailing chemical

sensations, sweet, sour, bitter and salty, among which sweet and sour tastes are

predominant. Bitterness predominate some fruits while saltiness is a rare factor in fresh

fruits taste (Rathore et al., 2007). Fruits having sweet taste due to sugars and sourness

because of organic acids are main components of many fruits taste (Kays, 1991).

Maximum fruit tastes were recorded in fruits of both cultivators by application of higher

doses of both chemicals due to hydrolysis of sugar and further sugar convections.

Untreated fruit showed slow rate of hydrolysis resulting in increased spoilage (Fan and

sokorai, 2005; Rohwer and Erwin, 2008).

Fruit texture is mainly attributed to cell wall integrity and stored carbohydrates

such as pectin, starch etc. SA and MeJA maintained fruit textural score after 90 days of

storage which may be due to decreased breakdown of insoluble pectin substances.

Weichmann (1987) similarly stated that the activity of pectin enzymes (esterase and

polygalacturonidase) is involved in the breakdown of insoluble pectin forms to soluble.

Untreated fruit showed more reduction of textural properties due to decrease in fruits

texture depicts hydrolytic changes in the fruits resulting in exhaustion of sugar

269

compounds and decrease in firmness (Malundo et al., 2001; Abbasi et al., 2010). Overall

acceptability results in result of net average of sensory attributes (fruit texture, taste or

flavor), evidently depicts a clear picture about the quality of grapefruit cvs‘ Ray Ruby and

Shamber which were greatly regulated and affected by salicylic acid (SA) and Me JA

application with different concentrations. Fruits treated with higher concentrations SA

and MeJA marked comparatively higher scores by the panelists than the fruits those were

treated with lower concentrations. Generally, decreasing trend was observed for overall

acceptability during storage. In consonance to our results, Babalar et al. (2007) also

reported that all the SA acid concentrations and Me JA significantly increased overall

acceptability of strawberry fruits especially treated with 12.0 mmol L-1 salicylic acid. It

was also reported that untreated fruits showed lower fruit quality which may be due to

high starch reserves and upon ripening starch was not converted into sugars (Pelayo et al.,

2003).

Phenolics being secondary plant metabolites are synthesized by all plants. These

are responsible for the flavor and color of fruit products (Jeong et al., 1993). Robert et al.

(2003) stated that phenolics are involved in several functions such as nutrient absorption

in plants, protein synthesis, enzymatic activities and photosynthesis. Many phenolic

compounds act as antioxidants, but in higher quantity they become browning substrates.

PPO and reactive oxygen species function as main oxidants during phenolics function, as

substrates and antioxidants (Robarts et al., 2011). They exist generally as flavonols in

fruit peel (Hamauzu, 2006). The fruits treated with SA @ 12 mM and MeJA @ 5mM

showed minimum reduction in phenolic compound during the storage (maintained) as

compared to the fruits those were treated with lower concentrations and without

treatments (control). Untreated fruit showed more reduction of TPC which might be due

to reduction of different enzymes and reducing electronic transfer- based antioxidant

which might have reduced many TPC during storage. The loss of phenolic compounds

during storage can be associated with several enzymatic and non-enzymatic reactions,

ethylene production being superior (McDonald, 1998). Similar findings have also been

described by Huang et al. (2008) who reported that that SA treated ‘Cara cara’ navel

oranges showed increased total phenolic content, higher concentration of SA having more

profound effect in this respect. There is also evident that exogenously applied SA with

suitable dose enhanced the efficiency of antioxidant system in plants (Hayat et al., 2007).

Zeng et al. (2008) also reported that salicylic acid treatment significantly enhanced

phenylalanine (PAL, peroxidase POD and -1, 3-glucanase activity in grape berries which

270

may help them to protect themselves against chilling stress during storage. Antioxidants

are compounds capable of quenching ROS without undergoing conversion, themselves, to

destructive radicals (Hodges, 2003). To ascertain dietary importance of fruits and

vegetables it is also important to estimate their antioxidant activity. Higher concentration

of both chemicals maintained TAC during storage of both cultivators which might be due

to counteracted balancing between increased free radicals and increased FRSA. Both

chemicals being TAC, regulates some of fruit defense systems and nutrition components

biosynthesis including antioxidant activity (Huang et al., 2008). Untreated fruit reduced

TAC which might be due to imbalance electronics structure and more leakage of cell

membrane. Results of present study are supported by the previous findings of various

scientists (Cai et al., 2006; Lu, 2002). The other reason for lower reduction in TC and TF

contents during storage by the application of higher doses of both chemicals might be due

to decreased respiration which prevents fruit senescence during storage. It seems that

these compounds prevent enzymatic activities which have a role in anthocyanin synthesis

by slowing down ripening process. It is well documented that MeJA affects many

physiological events including coloration in fruit (Fan et al. 2005; Rohwer and Erwin,

2008). Higher doses SA @ 12 mM and MeJA @ 5 mM showed better results to maintain

phytochemical properties in compounds after storage. Maximum TGL and TL were found

with application of higher doses of SA@ 12mM and MeJA @ 5 mM which may be

attributed to fruit bitterness, because under low pH conditions, the A-ring lactone (LARL)

can be converted to limonin. It previous research it is reported that higher doses maintain

this convection (Rolle and Chism, 1987). Untreated fruits showed increased emzyamtic

changes as compare to those fruit that were treated with SA and MeJA. This is temporary

because, at a more advanced stage of oxidation, the molecules gradually lose this

property, and there is a drastic reduction in TL and TGL. These findings are in

accordance with the findings of some previous researchers (Goodner et al., 2001; Fan et

al., 2005)

The fruits treatments with SA @ of 12 mM and MeJA @ of 5 mM effectively

controlled the chilling injury development in grapefruit, as estimated by CI symptoms

percentage after 30, 60 and 90 days storage, but very little symptoms (0.33 and 0.33%)

were noted after 90 days. While, controlled fruits showed 2.66 and 2.33% chilling injury

after 90 days storage. It can be concluded that treated fruits might be build up some

defensive system due to less loss of antioxidants against the chilling injury therefore these

remained safe from the chilling injury. It is because oxidative stress caused by the

271

accumulation of reactive oxygen species (ROS) together with a reduction in the anti-

oxidant system are involved in CI development in fruits during storage ( Harker and

Maindoral, 1994). Similar results were also reported by Wang et al. (2006) and Cao et al.,

2009 of those worked on peaches and pomegranates respectively and found that higher

concentrations of SA in the range from 0.35 to 12.0 mM were more effective to control

the chilling injury than lower ones. The effect of SA and Me JA against CI in grapefruit

was attributed to its ability to develop antioxidant systems and heat shock protein (HSPs)

that minimized the Cl symptom during storage (Wang et al., 2006). It is also reported that

higher doses develop expression of a set of defense genes that protect the fruit against the

CI (Fung et al., 2004; Cao et al., 2009). More chilling injury symptoms in untreated fruits

could also be due to the leakage of cell membrane and loss of integrity of membrane with

imbalance of electron due to more ethylene production during storage. Many researchers

also reported the similar findings (Martine et al., 2004; Zhou et al., 2002; Lurie and

Crisosto, 2005).No fungal decay was visually observed on treated fruits after 30 to 60

days of storage but minimum decay was noted after 90 days storage on fruits those were

treated with lowers doses. However, SA @ 12 mM and MeJA @ 5 mM concentrations

proved to be the most effective to reduce fungal decay at the end of storage time which

may be due to better developed defense system (Jiankanget et al., 2006) or working of

these chemicals as anti-senescent effects (Asghari and Aghdam, 2010). In earlier studies,

SA treatment prevented the decay in peaches (Wang et al., 2006), strawberry (Babalar et

al., 2007) and grape (Ranjbaran et al., 2011). Moreover it is also reported that SA

treatment strengthens defense system through enhancing activities of antioxidant enzymes

that improve resistant in treated fruit against the fungal attack (Xu and Tian, 2008).

Fruit weight losses are known as most significant physiological disorder during

postharvest life. Low fruit losses during storage in treated fruit also singled the superiority

of SA MeJA by reducing the respiration, transpiration and metabolic activities of fruit and

these three activities are directly related with fruit weight loss during storage. Treatment

of SA and MeJA cause the hindrance in respiration by generating free radicals (Wolucka

et al., 2005) by closing stomata (Manthe et al., 1992; Zheng and Zhang, 2004) and

slowing down respiration which may have ultimately reduced the weight loss of fruit. The

finding of Shafiee et al. (2010) also shown that strawberry fruits showed less fruit weight

loss than control when salicylic acid was supplied accomplished with nutrients.

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Pre-harvest sprays of SA@ 12mM and MeJA @ 5 mM showed higher

biochemical parameters such as TSS (5.92 and5.83, 6.17 and 6.09 ºBrix),

ascorbic acids ( 35.86 and 35.86, 39.17 and 39.17 mg/100g), total sugars (5.88

and 5.77 , 6.31 and 6.18%), reducing sugars (3.74 and 3.64%, 4.05 and 3.96%)

and non-reducing sugars ( 2.14 and 2.14, 2.26 and 2.12%), TSS/acidity rato values

(4.29 and 4.67, 5.82 and 5.38 ) in fruits of Ray Ruby and shamber respectively

after 90 days storage. Maximum organoleptic scores for overall acceptance (7.33,

7.22 and 7.66,7.44) and higher totalphenolic compounds (166.29 and 165.76,

170.48 and 167.28 mgGAE/100g), total antioxidants (72.63 and 71.37, 75.34 and

74.21%), Total carotenoids (16.40 and 16.32 , 18.09 and 18.03 mg/100g), total

flavonoids contents (55.74 and 53.43,58.30 and 56.04 mgCEQ/100g) and total

limonin contents (11.95 and 12.04, 10.66, 10.78 µg/mL) with minimum chilling

injuries (1.57 and 1.42%, 0.0 and 0.0%) and fruit rots (4.23 and 3.90%, 0 and 0%)

were also recorded in same fruits.

SA @12 mM and MeJA @ 5 mM maintained significantly higher levels of total

phenolics, total carotenoids and total flavonoids as well as main TL compounds

than control. In addition, MeJA and SA markedly reduced fruit decay and

maintained significantly higher antioxidant activity. Thus, MeJA has a potential

application in postharvest treatment for reducing decay and maintaining a high-

quality product after storage.


controlled the chilling injury development in grapefruit, as estimated by CI

symptoms percentage after 30, 60 and 90 days storage, but very little symptoms

(0.33 and 0.33%) were noted after 90 days.

Overall acceptability scores were obtained by higher doses of SA @12 mM and

MeJA @ 5 mM as compared with that of other concentrations and control fruits

during 90 days of storage.

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Chapter-5

GENERAL DISCUSSION, CONCLUSIONS, RECOMMENDATIONS

5.1 General discussion

Citrus fruits are grown in more than 64 countries of the world. Citrus ranks first with

respect to area and production in Pakistan among the fruit crops. It contributes important

nutrients, vitamins A and C, folic acid, potassium and dietary fibre. The use of grape fruit in

diet is considered as preventive against cancer due to higher contents of flavonoids and

limonoids. These phytochemicals in grapefruit are considered very important for human body

requirements due to their medicinal properties. Therefore it is important that grapefruit

should be harvested and consumed when it has maximum quantity of these chemicals. A very

little information is available about the effects of early and delayed harvesting dates on these

compounds. Moreover, the postharvest losses in the developed countries are 10-15% while in

under developing countries these reach up to 20-50% depending upon the commodity. Grape

fruits of Pakistan are often of poor quality because growers start its early harvesting (July and

August) at immature stage. Maturity is one of the main factor which effects citrus quality,

which drastically affects its cultivation, production and processing.

The harvesting of grapefruits in Pakistan is started in July and continues up to late

March. To investigate the nutritional status, fruits were harvested in middle five months and

were analysed. The physical and chemical parameters of fruits are the important indicators of

their maturation for internal and external quality, decisive factors for accomplishment of

market demands. Maximum values of physiological parameters (fruit weight, peel, rag, juice)

increased up to December and fruits harvested later in January significantly reduced their

weights. The increase in size up to December may be due to continuous cell division and cell

enlargement, more photosynthesis assimilates translocation to fruits; as the fruit remained

more time on plant. Maximum juice weight, peel weight diameter up to December is due to

the increase cell expansion and expands cells has a ability to increase the vesicles capacity

for juice accumulation. Fruit those were harvested in later dates showed reduction of juice

due to more transpiration and respirational changes taking place in fruits. No significant

results were noted regarding the number of seed, healthy and aborted seed during all

harvesting dates because fruit attained seed in early dates then no change occurred in later

274

harvesting dates. Fruit those were harvested in December showed more fruit firmness than

the fruit those were harvest in early stage. However, surprisingly early harvesting dates

showed lower level of cellulose and hemicelluloses in cell wall in flavedo tissue, and sugar

concentration was highest in the cellulose fraction, and lowest in the hemicelluloses fraction.

Fruit harvested in December showed maximum pH of juice values than the fruits those were

harvested in early months during both year of study due to more water contents in fruit which

correlates to fruit developmental stages. Fruit marketable quality is largely determined by the

stage of development of fruit and harvest time. Fruit harvested in December showed higher

TSS contents as compared to fruit those were harvested in early and January. Minimum

acidity and higher level of total, reducing, non reducing sugar level in December may be due

to the increase in sugar and acids level as the season advances. The concentrations of

titratable acids in grape fruit gradually decrease as the fruit develops and full mature.

Vitamin C in grape fruit juice decreased as the season advanced. Grapefruit contain

significant levels of biologically active components with physiological and biochemical

functions on human body. Grape fruit is an excellent food characterized by a low content of

calories. Maximum TPC were found in December fruit as compared to fruit those were

harvest in January due to series of chemical and enzymatic changes like glycoside hydrolysis

by glycosidase, phenolic compounds oxidation by phenol oxidizes and polymerization of free

phenolic compounds. Early harvesting dates and January showed lower values of TPC due to

reduction in these phenolic compounds is a symptom of ripening in most fruits. Maximum

contents of TF, TC in fruit those harvested in December as compared to fruit those were

harvested in early months and January may be attributed to the fact that low night

temperature stress in citrus fruits produces internal ethylene in quantities large enough to

destroy chlorophyll and promote development of carotenoids. Early harvesting dates and

January harvesting showed reduction in these compounds which may be due to higher

process of ripening which reduced the TC, TF contents in fruit. Early harvesting dates and

January showed reductions in these compounds were noted due to higher process of ripening

which reduced the TC, TF contents in fruit.

Results regarding biochemical parameters exhibited that fruits stored at 8ºC revealed

higher fruit juice pH, TSS, TS, RS and reduced TA, NRS and Vitamin C as compared to

fruits stored at 6ºC and held on tree. The possible reasons for high sugars were the

275

conversion of organic acid into simple sugars optimized at 8ºC as compared to other

treatments. In contrast, fruit stored at 6ºC exhibited lower Vitamin C contents compared to

fruit stored at 8ºC. The possible reason for less Vitamin C could be due to the slower

metabolic process at 6oC and it indicates that fruits were under stress at lower temperature.

Likewise, similar trend was also observed for tree stored fruit as these fruits also exhibited

reduced Vitamin C than fruit stored at higher temperature and lead to decreased TSS contents

than the fruits stored at 8oC after 90 days of 1st analysis. These changes may be due to the

fact that after 1st harvesting the temperature was dropped and fruit was physiologically

matured and ripened so might be some senesces processes initiated so after 90 days of 1st

harvest a decline was noted. In contrast, fruits stored at 8oC showed higher TSS and reduced

TA during storage. Phytochemicals exhibited that fruit stored at 8ºC revealed higher TPC,

TAA, TC, TF and TL contents as compared to fruit stored at 6ºC and held at tree. On the

other hand fruit stored at optimized temperature (8ºC) exhibited higher phytochemicals

possibly due to the activities of PAL enzyme that has been reported to be involved in TPC

metabolism. In contrast, fruit stored at 6ºC revealed reduced TPC and this reduction may be

due to gradual enzymatic changes during storage. However, tree stored fruit showed higher

reduction in TPC contents due to continuous changes of temperature which exhibited reduced

activities of enzyme and degradation of cell wall that ultimately reduced the TPC contents of

fruit (Teiz and Zeiger, 2010). Chilling injury was the major disorder limiting the storability

and marketability of grapefruit. All of these symptoms were significantly lowered at 8ºC for

up to 90 days of cold storage. Because of the high susceptibility of grapefruit to Chilling

injury during cold storage at 6°C or lower temperature, its quality had badly affected. Lower

fruit rot symptoms were noted at 8ºC for up to 90 days of cold storage due to suppression of

disease spores in fruit. Fruit stored at 6ºC showed more disease due to lower temperature

which henced the germination of spores formation so in this regard more fruit rot was noted.

Overall acceptability results exhibited that average of sensory attributes (fruit texture, taste or

flavor), evidently depicts a clear picture about the quality of grapefruit. Fruit stored at 8ºC

revealed higher scores even after 90 days storage as compared to fruit stored at 6ºC and tree

held fruit due to changes in starch reserves in fruit. Hot water treatments and storage period

showed that pH increased and acidity decreased in fruit juice those were treated with HWT

for 3 min + TBZ as compared to fruit those were treated for long period and untreated fruit.

276

Fruit treated with HWT for 3 mins +TBZ and stored for long period significantly decreased

titratable acidity which may be due to decrease in citric acid and increases in soluble solids

content. Higher values of TSS and sugar (TS, RS, NRS) in fruit those were treated with

HWT for 3 mins + TBZ indicated that accumulation of sugar related process completed

successfully in these fruit as compared to other fruits. The changes in TSS are directly

correlated with hydrolytic changes in the starch concentration during the storage period. The

results regarding to the phytochemicals were non-significant between hot treatment, storage

period total phenols and antioxidant activity, TC, TF and TL while the amounts of these

phytochemicals reduced with the increased storage period. HWT exerted no adverse effects

on the sensory attributes in both cultivars. Hot water treatment maintained the freshness and

improved their general appearance without affecting other quality parameters like

organoleptic attributes including sourness, sweetness, texture, taste and over quality. Fruit

those were treated with HWT for 3 min at 53ºC showed maximum sweetness, lower sourness

higher texture, taste and overall quality as compared to fruit those were treated with higher

immersed time for 4 min at 53ºC and untreated fruits. Fruit those were treated with hot water

treatment showed entirely cosmetic in nature on the outer peel of the very good eating quality

at the end of this evaluation. Thus, the major problems are pathological rather than

physiological. In spite of the significant improvement with the heat treatment, substantial

problems with fruit appearance remain, especially on the mature fruit after 90 days.

The results elucidated that highest pH was observed in the fruits treated with chitosan

@ 140 mg per fruit-1 while it was lowest in fruits treated with lower doses of chitosan or in

uncoated fruit. This change in pH during storage period might be due to the alteration of

biochemical condition of fruit or lower rate of respiration and metabolic activity of fruit.

Higher doses of chitosan and storage period showed higher total soluble solid values than the

fruits treated with lower doses and uncoated fruit. The changes in TSS are directly correlated

with hydrolytic changes in the starch concentration during the storage period. Likewise, fruits

treated with higher doses of chitosan showed lower acidity than fruits treated with lower

doses. Fruit treated with chitosan @ 140 mg per fruit-1 showed significantly higher ascorbic

acid contents after 30 days as compared to the fruits treated with lower doses and control

fruits. After 30 days storage then reduction trend was observed in all treatment of chitosan

however untreated fruits showed more reduction of Vitamin C after 90 days storage in both

277

grape fruit cultivators. This might be due to slow ripening and compositional changes of

gases in stored fruit. Untreated and lower concentration showed more reduction of ascorbic

acid after 60 and 90 days due to fast oxidation and changes of oxygen level. Fruit treated

with chitosan showed significantly higher TS, RS, NRS during storage expect control. Total

sugars of the fruits are considered one of the basic criteria to evaluate the fruit ripening. It is

clear from the results that at the time of harvest the sugars were very low but with the

passage of time, ripening was enhanced resulting in the increase of total sugars. With the

passage of time, respiration, transpiration and other metabolic processes enhanced. Due to

this, starches were converted into sugars and reducing sugar quantity was increased. Fruit

treated with chitosan @140 mg per fruit-1 showed maximum TSS/acidity which might be due

to change in respiration pattern in cell membrane. Maximum reduction were noted at lower

concentration and uncoated fruit after 90 day which might be due to conversion of starch to

sugars as a result of moisture loss and increased acidity due to physiological changes during

storage. Fruit treated with chitosan showed maximum quantities of phytochemical in fruit

after 30 and 60 days of storage than the one seen during end of experiment. Higher doses of

chitosan showed lower reduction as compared to fruit those were uncoated and treated with

lower concentration. Maximum quantities of TPC, TAA, TC and TF were recorded after 30

and 60 days after storage. Chitosan may inhibit the activity of polyphenol oxidase, an

enzyme that is involved in the process of phenolic compound degradation. Fruit treated with

chitosan showed maximum TAA and TF, TC after 90 days as compared to fruit those were

analyzed after 90 days storage this is due to chitosan have ability to develop a modified

system for exchange of gases. Untreated fruit and lower concentration of chitosan showed

maximum reduction of these compounds after 90 days be due to breakdown of cell structure

in order to senescence phenomena during storage. Fruit treated with chitosan showed no

chilling injury, fruit rot, during whole storage period possibly due to mixture of hydrolyzed

starch that causes the semipermeable barrier in cell wall which prevents spores entering in

cell wall. Sensory evaluation for both varieties showed that the fruits treated with chitosan

showed more sweetness and sourness trend was decreased when noted after 90 day of

storage. This increase in sweetness might be the result of fast ripping of fruits resulting in

increased sugar during storage. Fruit texture is mainly attributed to cell wall integrity and

stored carbohydrates such as pectin, starch etc. Chitosan maintained fruit textural score after

278

90 days storage which may be due to decreased breakdown of insoluble pectin substances.

Coated fruits showed overall good quality than uncoated fruit. This improvement in quality

may be attributed to the increases in organic acids during senescence. The results indicated

that the fruits treated with SA and Me JA showed better performance in (TSS, Vit C, TS, RS,

NRS and TSS/Acid) in both gape fruit cultivars. This better performance may be due to the

less losses of organic acid and slow respiration change in treated fruits. Maximum sweetness

in both cultivars was measured during storage by application of higher doses of SA and

MeJA after storage which may be due to increase in sugars content due to the activity of

sucrose-phosphate synthase. Maximum sweetness in both cultivars was measured during

storage by application of higher doses of SA and MeJA after storage which may be due to

increase in sugars content due to the activity of sucrose-phosphate synthase.

Maximum fruit tastes were recorded in fruits of both cultivars by application of

higher doses of both chemicals due to hydrolysis of sugar and further sugar convections.

Untreated fruit showed slow rate of hydrolysis resulting in increased spoilage. Fruit texture is

mainly attributed to cell wall integrity and stored carbohydrates such as pectin, starch etc. SA

and MeJA maintained fruit textural score after 90 days of storage which may be due to

decreased breakdown of insoluble pectin substances. They exist generally as flavonols in

fruit peel (Hamauzu, 2006). The fruits treated with SA @ 12 mM and MeJA @ 5mM showed

minimum reduction in phenolic compound during the storage (maintained) as compared to

the fruits those were treated with lower concentrations and without treatments (control).

Untreated fruit showed more reduction of TPC which might be due to reduction of different

enzymes and reducing electronic transfer- based antioxidant which might have reduced many

TPC during storage. The other reason for lower reduction in TC and TF contents during

storage by the application of higher doses of both chemicals might be due to decreased

respiration which prevents fruit senescence during storage. It seems that these compounds

prevent enzymatic activities which have a role in anthocyanin synthesis by slowing down

ripening process. It is well documented that MeJA affects many physiological events

including coloration in fruit.


controlled the chilling injury development in grape fruit, as estimated by CI symptoms

percentage after 30, 60 and 90 days storage, but very little symptoms (0.33 and 0.33%) were

279

noted after 90 days in fruits those were treated with lower doses. Controlled fruits without

any treatments showed 2.66 and 2.33% chilling injury after 90 days storage. It can be

concluded that treated fruits might have build up some defensive system due to less loss of

antioxidants against the chilling injury therefore these remained safe from the chilling injury.

No fungal decay was visually observed on treated fruits after 30 to 60 days of storage but

minimum decay was noted after 90 days storage on fruits those were treated with lowers

doses. However, SA @ 12 mM and MeJA @ 5 mM concentrations proved to be the most

effective to reduce fungal decay at the end of storage time which may be due to better

developed defense system. Fruit weight losses are known as most significant physiological

disorder during postharvest life. Low fruit losses during storage in treated fruit also singled

the superiority of SA MeJA by reducing the respiration, transpiration and metabolic activities

of fruit and these three activities are directly related with fruit weight loss during storage.

Treatment of SA and MeJA cause the hindrance in respiration by generating free radicals and

close stomata.

5.2 Conclusions

The results suggested that maturity parameters and external colour indices are useful trait, for

determining citrus fruit quality and suitable harvesting time. The quantitative composition of

phenolics, lioimoin carotenoids, pectin and flavonoids of grapefruit juice represent good

parameters for characterization of the product, content of dietary phytochemicals and health-

promotion value of selected citrus fruit. This may have implications for both the nutritional

value and oxidative damage inhibition during post-harvest storage of fruits.

1. To optimum fruit quality and antioxidant capacity during late November and early

December, are the best dates for harvesting of grape fruit.

2. Storage temperature was the prime limiting factor for shelf life and quality of grape

fruit and 8ºC was observed best for storage of grape fruit for maintained all

phytochemical during storage.

3. The TPC, TF, TC content decreased faster during tree storage as compared to cold

storage.

4. It is concluded that pre-storage treatment with chitosan @ 140 mg per fruit-1 showed

best results regarding inhibition of fungal and pathogenic attack and maintained the

phytochemical during storage at 8ºC.

280

5. SA (@12 mM), MeJA (@4 mM) are best dozes to control the Fruit loss, chilling

injury, fruit rot and to improve the phytochemicals under storage.

5.3 Recommendations

1. Grapefruit should be harvested at fully commercial maturity stage that was in month

of December with fully phytonutrient.

2. Growers should prefer to store the citrus fruit in cold storage rather than tree storage

which could be beneficial to avoid the mechanical injury during transportation and

more maintained quality as compared to tree held fruit.

3. Citrus processing industry should follow best storage temperature at 8°C that

maintained fruit quality and shelf life of grape fruit.

4. Citrus industry should incorporate hot water treatment into the packinghouse sorting

line and it can be considered as a classification of organic methods.

5. HWT treatment for 3 min at 53ºC maintained fruits quality and shelf life of grape

fruit.

6. Chitosan should be preferred for citrus industry to improved quality and reduce

postharvest disease during storage.

7. Grower should used pre harvest spray of SA (12mM) and MeJA (4mM) to improve

quality and shelf life of grape fruit.

281

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improves quality of “Mari Delicia” peach fruit. Acta. Hort., 880: 191-197.

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prr.hec.gov.pkprr.hec.gov.pk/jspui/bitstream/123456789/7062/1/Waseem_Ahmed... · DECLARATION I hereby declare that contents of thesis, “Harvest maturity and post-harvest factors