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STUDIES ON EFFECTS OF GAMMA IRRADIATION ON DEODORIZATION OF COCONUT OIL AND SHELF LIVES OF

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STUDIES ON EFFECTS OF GAMMA IRRADIATION ON DEODORIZATION OF COCONUT OIL AND SHELF LIVES OF TUBEROSE AND MARIGOLD CUT FLOWERS

Probir Kumar Ghosh, Sayani Pal and Paramita Bhattacharjee*Probir Kumar Ghosh, Sayani Pal and Paramita Bhattacharjee*Department of Food Technology and Biochemical Engineering, Jadavpur University, Department of Food Technology and Biochemical Engineering, Jadavpur University,

Kolkata 700 032, India(*Corresponding author: pb@ftbe.jdvu.ac.in)(*Corresponding author: pb@ftbe.jdvu.ac.in)

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Among oil crops, coconuts occupy a prime niché in south India and are also extensively cultivated in West Bengal. Coconut oil is a rich source of lauric acid, besidesmother’s milk and is a rich house of phytochemicals (such as phenols, alkaloids and glycosides); however, its usage as an edible oil in eastern India is limited owing to its

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mother’s milk and is a rich house of phytochemicals (such as phenols, alkaloids and glycosides); however, its usage as an edible oil in eastern India is limited owing to itsunpleasant lactonic odor. Among the horticultural produce, tuberose and marigold flowers are extensively cultivated in West Bengal. These flowers are highly valued fortheir ornamental appeal and reportedly have therapeutic potency. However, their short shelf lives limit their commercial utilization for export and therapeutic applications.their ornamental appeal and reportedly have therapeutic potency. However, their short shelf lives limit their commercial utilization for export and therapeutic applications.Therefore, there is huge wastage of these oil crops and horticultural products. In our study, low to medium dose irradiation has been employed for reduction of off-odor ofcoconut oil (for wider acceptability as frying oil) and for enhancement in shelf lives of tuberose and marigolds cut flowers (for preserving their therapeutic potential). Thecoconut oil (for wider acceptability as frying oil) and for enhancement in shelf lives of tuberose and marigolds cut flowers (for preserving their therapeutic potential). Theeffects of irradiation on these commodities were analyzed by hedonic sensory evaluation and assays of their physiochemical and phytochemical properties. Our studiesshowed promising results in reduction of obnoxious odor in coconut oil and extension of shelf lives of these flowers with concomitant preservation of their physiochemicalshowed promising results in reduction of obnoxious odor in coconut oil and extension of shelf lives of these flowers with concomitant preservation of their physiochemicaland phytochemical properties.

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Overall appearance

Irradiated marigold flower (0.02-0.8 kGy) on day 5

Irradiated marigold flower (1.0-2.0 kGy) �

Overall

appear… Irradiated

coconut �

Overall appearanc

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Irradiated tuberose flower (0.05 kGy) on

� Coconut oil, most commonly obtained from thedried coconut kernel (copra) is rich in

�Both tuberose and African marigold cut flowersare ornamental flowers; however, they haveshort shelf lives which limit their commercial

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Color

Visual fungal

flower (1.0-2.0 kGy) on day 5

Irradiated marigold flower (2.3 kGy) on

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coconut oil (4 kGy) at 3 months

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day 5

Irradiated tuberose flower

dried coconut kernel (copra) is rich inphytochemicals (such as phenols, alkaloids andglycosides) [1, 2] but has a characteristicobnoxious odor owing to presence of lactones and

short shelf lives which limit their commercialvalue

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on

flower (2.3 kGy) on day 5

Irradiated marigold flower (2.5 kGy) on day 5

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Irradiated coconut oil (6 kGy) at 3 months

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ColorShrinkage of petals

tuberose flower (0.05 kGy) on day 5

Non-irradiated

obnoxious odor owing to presence of lactones andoctanoic acid [3] which limit its use as an edible oil �Common procedures for preservation of

flowers include chemical preservatives and/orCAP/MAP packaging, which may leave harmful

FirmnesShrinkage of

day 5

Experimental control on day 5

OdorBody

Non-irradiated coconut oil oil at 3 months

AromaFirmness

Non-irradiated tuberose flowers on day 5� The conventional physical refining processes

cause thermal degradation of phytochemicals

CAP/MAP packaging, which may leave harmfulresidues in flowers and increase the cost,respectively [4] Firmnes

sge of petal

Negative control on day 5

Sensory evaluation of irradiated coconut oil, tuberose and marigold flowers with respect to

Taste

monthsrespectivelyrespectively [4]

Sensory evaluation of irradiated coconut oil, tuberose and marigold flowers with respect to control

Non-thermal green technology of gamma (�) irradiation

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� Reduction in obnoxious odor in coconut oil by �-irradiation� Improvement in shelf life of tuberose and marigold cut flowers by �-irradiation� Study of shelf lives of irradiated coconut oil, tuberose and marigold flowers by Storage (days)

% Moisture of Irradiated Tuberose and Marigold Flowers with Storage� Study of shelf lives of irradiated coconut oil, tuberose and marigold flowers by

evaluation of sensory, physicochemical and phytochemical properties

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� Oil and flowers:� Coconut (Cocos nucifera L.) oil (expeller pressed from West coast tall variety coconut copra, M/s KPL Oil

Mills, Kerala, India).� Tuberose (Polianthes tuberosa L., Calcutta single variety) and marigold (Tagetes erecta L., African variety) cut

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Total phenol content of irradiated tuberose and marigold flowers with storage� Tuberose (Polianthes tuberosa L., Calcutta single variety) and marigold (Tagetes erecta L., African variety) cut

flowers were procured from Barasat, 24 Paraganas (N), West Bengal and authenticated by West Bengal FoodProcessing and Horticulture Development Corporation Limited, Kolkata.

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Processing and Horticulture Development Corporation Limited, Kolkata.� Packaging material:� PET bottles and LDPE packets (both authenticated by National Test House, Kolkata) were procured form a local

supermarket.

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supermarket.� Chemicals:� DPPH (M/s Sigma, USA), ethanol, sodium carbonate and Folin-Ciocalteu (M/s Merck, Germany).� Gamma Irradiation Facility: �

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Storage (days)

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Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers IC50 Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers

� Gamma Irradiation Facility:� GC 5000 unit (BRIT, Mumbai) at National Instruments Laboratory (NIL) campus, Jadavpur University (JU).

Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers IC50 Value of DPPH Radical Scavenging Activity of Irradiated Tuberose and Marigold Flowers with Storage

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�From 3 months study, greatest reduction in obnoxious odor (sensorically) of coconut oilNon-irradiated/ non packaged

Marigold cut flowers (negative control)Tuberose cut flowersCoconut oil

�From 3 months study, greatest reduction in obnoxious odor (sensorically) of coconut oilwas found in 4-6 kGy, without affecting physiochemical and phytochemical properties

�Irradiation at 0.05 kGy for tuberose flowers showed maximum shelf life (12 days) vis-a-�Irradiation at 0.05 kGy for tuberose flowers showed maximum shelf life (12 days) vis-a-vis control (non-irradiated flowers, 9 days) with appreciable antioxidant properties

�2.3 kGy was found to be the optimized dose of irradiation for marigold flowers, leading�2.3 kGy was found to be the optimized dose of irradiation for marigold flowers, leadingto enhancement of shelf-life by 6 days w.r.t. non-irradiated/non packaged flowers (shelf-life of 5 days)

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LDPE packaged/�-

irradiated at 0.02-

LDPE packaged/ non-irradiated(experimental Flowers packaged in LDPE

packets

life of 5 days)

irradiated at 0.02-2.5 kGy

(experimental control)packets

This study established novel applications of gamma irradiation technology forreduction of obnoxious odor of coconut oil and improvement of shelf life ofStorage atStorage at

23 � 2�C, 80% RH (in a humidity chamber)

Oil packaged in nitrogen flushed PET bottles

�-irradiation at 0.05 and 1.0 kGykGy

reduction of obnoxious odor of coconut oil and improvement of shelf life oftuberose and marigold cut flowers, without affecting their physiochemical andphytochemical properties

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(in a humidity chamber) (in a humidity chamber)

Selection of 2 favorable dose of �-irradiation at 2, 4, 6, 8 and 10

kGy

Flowers stored at 15�1�C, 70%

phytochemical properties

��������������������1. Dayrit C. (1997). Medicinal aspects of coconut oil, Coconuts Today, 14, 5-19.2. Ghosh P.K., Bhattacharjee P., Mitra S. and Poddar-Sarkar M. (2014). Physicochemical and Phytochemical

Analyses of Copra and Oil of Cocos nucifera L. (West Coast Tall Variety), International Journal of Food

Selection of 2 favorable dose of irradiation out of 13 doses (0.02-2.5

kGy) by sensory analyseskGy and storage at 23�2�C in

darkFlowers stored at 15�1�C, 70%

RH (in a controlled environmental chamber) Analyses of Copra and Oil of Cocos nucifera L. (West Coast Tall Variety), International Journal of Food

Science, Article ID: 310852, http://dx.doi.org/10.1155/2014/310852.3. Santos JER, Villarino BJ, Zosa AR and Dayrit FM. (2011). Analysis of volatile organic compounds in virgin

coconut oil and their sensory attributes, Phillipine Journal of Science, 140, 161-171.Physicochemical

(%moisture), phytochemical (total

chamber)

Evaluation of Evaluation of Evaluation of Evaluation of

sensory, physicochemical and coconut oil and their sensory attributes, Phillipine Journal of Science, 140, 161-171.4. Halevy AH and Mayak S. (1981). Senescence and post harvest biology of cut flowers II. Horticulture

Reviews, 3, 59-143.

(%moisture), phytochemical (total phenol content and DPPH activities)

analyses of selected irradiated flowers

Evaluation of sensory, physicochemical and

phytochemical properties of irradiated flowers

irradiated oil samples

sensory, physicochemical and phytochemical properties of

irradiated oil samples

���� � ���� �� ����� � ���� �� �w.r.t. controlw.r.t. control

Optimization of best irradiation

irradiated flowersirradiated flowers���� � ���� �� ����� � ���� �� �

Probir Kumar Ghosh acknowledges DST-INSPIRE (IF: 131031) and Sayani Pal acknowledges UGC-Optimization of best irradiation dose and assessment of shelf lifeAssessment of shelf lifeAssessment of shelf life

Probir Kumar Ghosh acknowledges DST-INSPIRE (IF: 131031) and Sayani Pal acknowledges UGC-NET; Ref. No.: 1575/(NET-JUNE 2012) for providing financial assistance for the study. The authors aregrateful to the Department of FTBE, JU for infrastructural facilities.