Efectos de Procesamiento en la Calidad Nutricional

de Frutas y Hortalizas

Dr. Diane M. BarrettFruit & Vegetable Products Specialist

University of California – Davis

Outline of Presentation• Fruits and Vegetables – What’s the

Difference? • Fruit & Vegetable Composition

(Macro- and Micronutrients)

• Effects of Various Preservation Technologies on Fruit/Vegetable Nutrients – 3 Studies• 2007 JSFA – fresh, canned, frozen (lit review)• 2012 JSFA – fresh, HPP, MW (lit review)• 2015 JAFC – fresh and frozen (original work)

Fruits & VegetablesWhat’s the Difference?

1. Botanical

1. Fruit = plant structures that contain seeds

2. Vegetables = other edible part of a plant (leaf, stem, root)

2. Chemical

1. Fruits = more acid and sugar, often less fiber

2. Vegetables = less overall flavor – if any it may be ‘bitter’

3. Physical

1. Fruits = more delicate, may require seed removal. Maintaining structure difficult, except if freeze dry.

2. Vegetables = more durable, need for peeling in some cases. More lignin/cell wall and structural integrity.

FigPeduncle

StrawberryReceptacle

MangosteenAril

Pomegranateseed

Outer layer Of the testa

PeachMesocarp

OrangeEndodermalIntralocular tissue

GrapesPericarp

Tomato

Placental intralocular tissue

Septum

PineapplePeduncle

Pedicel

Cashewapple

Spinachleaf blade

Leekswollen leaf base

Potatostem tuber

Carrotswollen tap root

Beetswollen hypocotyl

OnionBulb (underground bud)

BrusselsSproutsAxillary bud

AsparagusStem sprout

ArtichokeFlower bud

Broccoliswollen inflorescence

Celerypetiole

Lettucemain bud

*Less than 2% dry weight. Despite trace levels, an important source of vitamins & minerals

Fruit & Vegetable Composition

Water

Carbohydrate

Protein

Fats

Vitamins

Minerals

70-90%

4-20%

< 3.5%

<0.5%

trace *

trace *

Key Classes of F/V Nutrients Water Soluble

• B Vitamins• B1 – Thiamin• B2 – Riboflavin• B3 - Niacin• B6 – Pyridoxal• B9 – Folic acid

• Vitamin C• Phenolics

• Total• Specific

• Anthocyanins• Minerals • Fiber

Lipid Soluble

• Vitamin A• Vitamin E• Carotenoids

• Total• Specific

Dietary Reference Intakes (Institute of Medicine)

Vit A(RDA)

Vit B1

Vit B2

Vit B3

Vit B6

Folate

Vit C Vit E Ca K Na(AI)

Fiber(AI)

RDA/AI(mg/day)

0.80 1.15 1.2 15 1.3 0.40 82.5 15 1000 4.7 1.5 30

EAR (mg/day)

0.56 0.95 1.0 11.5 1.2 0.32 67.5 12 - - - -

RDA = Recommended Daily Allowance (in 1997 these broadened into DRIs)AI = Adequate IntakeEAR = Estimated Average RequirementDRI = Dietary Reference Intakes, from Institute of Med & US National Academy Sci FDA defines a “good source” of a nutrient as one serving of food containing 10 to 19% of the RDA or AI for that nutrient. DRIs refer to intake recommendations for various nutrients and include the aforementioned RDA and AI in addition to Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL). EARs are based on the daily requirements of 50% of healthy individuals in a particular group, while RDAs are set slightly higher to meet the needs of most (97-98%) individuals.

Suggested Nutrient Focus?

• Those that have established DRIs• Vitamin A Vitamin E• Vitamin B1 Calcium• Vitamin B2 Potassium• Vitamin B3 Sodium• Vitamin B6 Fiber• Vitamin B9 (folate)• Vitamin C

Current nutrition label based on older Reference Daily Intakes.

Fruit & Vegetable Sources - Vitamins & Minerals Nutrient EAR

RDA/AI

UL Unit Top Sources in Common Measures, USDA

Vitamin A 625 900 3000 µg carrot juice, pumpkin

Vitamin C 75 90 2000 mg orange juice, grapefruit juice, peaches

Vitamin K NE 120 ND µg kale, collards, spinach

Vitamin B6 1.1 1.3 100 mg fortified cereals, chickpeas

α-Tocopherol(Vitamin E)

12 15 1000 mg fortified cereals, tomato paste, sunflower seeds

Folate (B9) 320 400 1000 µgenriched white rice, fortified cereals, enriched cornmeal

Molybdenum 34 45 2000 µg legumes, grain products, nuts and seeds[8]

Niacin (B3) 12 16 35 mg fortified cereals

Potassium NE 4700 ND mg tomato paste, orange juice, beet greens

Riboflavin (B2) 1.1 1.3 ND mg spaghetti with meat sauce

Thiamin (B1) 1.0 1.2 ND mg fortified cereals

USDA National Nutrient Database, SR 23, 2010.

Stability of Nutrients in Processed Foods• Source: Klein and Kurilich, HortScience 1998

Nutrient

Neutral Acid Basic Oxygen Light Heat Water

Beta-Carotene

S SU S U U SU Slight sol

Vitamin C U S U U U U UU

Thiamin U S UU U S U U

Riboflavin S S U S UU SU SU

Folate U U S S U S SU

Minerals S S S S S S S

Vitamin E S SU S UU U SU insoluble

Effect of pH Effect of Environment

S=stable; SU=slightly unstable; U=unstable; UU=very unstable

Effects of Various Preservation Methods on Fruit & Vegetable Nutrients

• Summary of Literature Reviews: • 2007 JSFA – Fresh, Canned, Frozen

• Part I = Vitamin C, B, and phenolics• Part II = Vitamin A and carotenoids,

Vitamin E, minerals and fiber

• 2012 JSFA – HPP and Microwave• Vitamin A, B1, B2, B3, B6, B9, C, E• Phenolics, anthocyanins, carotenoids

• 2015 JAFC – Fresh and Frozen• Part I =Vitamins• Part II = Minerals, Fiber & Phenolics

2007 Publications

Fresh, Canned & Frozen

Fruits and Vegetables

Vitamin C - Fresh• Ascorbic acid degrades rapidly after harvest• Degradation continues during storage• Refrigeration slows loss

• Broccoli 7 days storage56% loss at 20 degrees C

0% loss at 4 degrees C

Vitamin C - Freezing• Loss ranges from 10-80%• Broccoli, peas, 20-30% loss• Retention depends on cultivar,

processing conditions.• Storage – 20-50% average loss after 1 year

(broccoli and spinach). Primarily due to temperature fluctuations – freeze/thaw and cell rupture, oxygen exposure.

• Greater retention in asparagus, peas. • Losses prevented by temperature control,

reducing storage period.

Vitamin C - Summary

• Fresh retains most, if eaten as soon as possible

• Canned, higher initial loss, minimal loss in storage at room temperasture

• Frozen, some loss initially, loss during storage if temperature not controlled

• USDA – similar levels for cooked fresh, canned, and frozen

B Vitamins - Summary

• B vitamins - sensitive to heat used in canning and storage at temperature higher than refrigeration.

• Inconsistencies with methodology and data reporting; difficult to draw conclusions.

• Considering that there are 5 B Vitamins with DRIs, very few studies have evaluated these. More research needed!

Vitamin A and Carotenoids - Canning

• Canning may improve extraction of carotenoids from cellular matrix

• Thermal processing causes a decrease in β-carotene (peaches etc.)

• Lycopene is less heat sensitive than β-carotene

• Processed tomatoes have more lycopene than fresh

Lycopene in Tomato Products (mg/100g wet weight)

6.5

7.7

11

9

0

2

4

6

8

10

12

Fresh CannedWhole

CannedDiced

Puree

Nagarajan et al 1999Note puree is 12 Brix.

Minerals and Fiber

• Calcium, Sodium, Potassium• Natural mineral content retained• Fresh, canned, frozen are similar• Vegetables canned without added sodium

have similar levels as fresh and frozen• No significant change in fiber due to

freezing or canning

Conclusions – Canned Food Alliance Lit Review• Current research on nutritional changes due to

postharvest handling and freezing, storage and cooking is sorely lacking.

• Few studies in the literature followed the same commodity from harvest through processing, storage and cooking.

• The effects of processing, storage and cooking are highly variable by commodity; within a commodity there are varietal and growing practices.

• Nutrient changes are often reported on wet rather than dry weight basis. F/V moisture contents change after harvest therefore the nutrient data is confounded with changes in moisture if expressed on wet weight basis.

120 media placements and more than 10 million viewers from CFA study.

2012 JFSA Publication

Fresh, HPP and Microwave

Fruits and Vegetables

2012 JFSA Literature Review• Focus on effects of HPP and Microwave

on nutrient content in fruits/vegetables• 3 databases: Agricola, CAB and FSTA• 1997 – 2010 publications• 734 references found• Abstracts of each reviewed, 124 found most

pertinent, those reviewed in detail• 29 found to be most significant for HPP• 15 most significant to MW, 11 to MW drying

HPP Manuscripts – General Remarks

• Most pubs focused on Vitamin C and carotenoids; few on B vitamins.

• Only 7/29 reported nutrients on dry weight basis.

• Most studies on juice; few on f/v pieces.• Comparative technology – typically thermal,

but few stated target (m.o., nutrient, enzyme)• 1 report on fiber, none on minerals or lipids.

HPP – Summary of Specific Effects• Vitamins B1, B2 and B6 – few studies,

however results show high retention • Vitamin B9 (folate) – unclear results• Vitamin C – contradictory - oxygen and

oxidative enzymes not controlled; however retention better than thermal treatment

• Carotenoids stable to HPP, may increase• Phenolics unaffected by HPP, may increase• Total fiber unaffected, some solubilization

2012 HPP Effects – Vitamins A & BVitamin

Commodity and Product

Wet vs Dry basis High Pressure Conditions % Loss % Gain Range

VITAMIN A            persimmon puree wet 350 MPa/5 min 45 (+45)

VITAMIN B1 (thiamin)            

model soln & juices wet 400-600 MPa/25°C/30 min 0-1 0

VITAMIN B2 (riboflavin)            

model soln & juices wet 400-600 MPa/25°C/30 min 0-1 0

VITAMIN B3 (niacin)            

OJ & seeds wet 200-500 MPa/30°C/1-10 min 0 0

VITAMIN B5 (pantothenic acid)            

sprouted alfalfa seed wet 500 MPa/25°C/10 min 0 0

VITAMIN B6 (pyridoxal)            

model soln & juices wet 400-600 MPa/25°C/1-30 min 0 0

VITAMIN B9 (folic acid)            

model solution wet 400-600 MPa/25°C/5-40 min 0 0-90various juices wet 500 MPa/20-60°C/40 min 0-90

2012 HPP Effects – Vitamin CVitamin

Commodity and Product

Wet vs Dry basis High Pressure Conditions % Loss % Gain Range

VITAMIN C            

buffer solution wet 850/60°C/6 hr 100

apple-broccoli juice wet 500 MPa/5 min 3

apple-broccoli juice wet 500 MPa/20 min 28

green beans (whole) wet 500 MPa/25°C/1 min 8

green peas (whole) wet 900 MPa/20°C/5-10 min 12

green peppers wet 100-200 MPa/10-20 min 10 to 15

kiwi-strawberry jam wet 400-600 MPa/10-30 min 0-5

melon pieces wet 600 MPa/10 min 50-90

orange juice wet 100 MPa/60°/5 min 10

orange juice wet 400 MPa/40°C/1 min 5 to 8

orange juice wet 350 MPa/30°C/2.5 min 0

red peppers wet 100-200 MPa/10-20 min 10 to 15

strawberry puree wet 600 MPa/30°C/15 min 6

tomato puree wet 400 MPa/40°C/15 min 29

tomato puree wet 600 MPa/20°C/15 min 6

2012 HPP Effects – CarotenoidsVitamin

Commodity and Product

Wet vs Dry basis High Pressure Conditions % Loss % Gain Range

CAROTENOIDS            

α-carotene carrot (whole) wet 600 MPa/25°C/2 min 00-72 (+34)

carrot juice wet 500 MPa/25°C/10 min 50orange juice wet 400 MPa/40°C/1 min 34

orange-lemon-carrot juice wet 500 and 800 MPa/25°C/5 min 0

β-carotene broccoli (whole) wet 600 MPa/25°C/2 min 17  

  carrot (whole) wet 600 Mpa/25°C/2 min 0  0-60

(+1-30)  carrot juice wet 500 MPa/25°C/10 min 40      orange juice wet 400 MPa/40°C/1 min   30  

β-cryptoxanthan orange juice wet 400 MPa/40°C/1 min 43 (+43)

Lutein broccoli (whole) wet 600 MPa/25°C/2 min 10   0-10 (+75)  green beans wet 600 MPa/25°C/2 min 0      orange juice wet 400 MPa/40°C/1 min   75  

Lycopene tomato puree wet 600 MPa/25°C/60 min 0tomato puree wet 500 MPa/20°C/2 min 60tomato puree wet 400 MPa/25°C/15 min 49

Zeaxanthan orange juice wet 400 MPa/40°C/1 min   45 (+45)

Total carotenoids carrot puree wet 600 MPa/20°C/15 min 58 (+8-58)

2012 HPP Effects – PhenolicsVitamin

Commodity and Product

Wet vs Dry basis High Pressure Conditions % Loss % Gain Range

PHENOLICS            

catechins apple juice 400 MPa/10 min 290 (+290)

dihydrochalcones apple juice wet 400 MPa/10 min 0 0

apple juice wet 400 MPa/10 min 31 (+31)

procyanidins apple juice wet 400 MPa/10 min 170 (+170)

cyanidin-3-glucoside model solution wet 600 MPa/20°C/30 min 0 0

blackberry puree wet 600 MPa/30°C/15 min 0

quercitin-4'-glucoside onion dry 400 MPa/5°C/5 min 33 (+33)

quercitin-3,4'-diglucoside onion dry 100-400 MPa/5°C/5 min 17 (+17)

Total quercitin onion dry 100-400 MPa/5°C/5 min 26 (+26)

Total phenolics blackberry puree wet 600 MPa/30°C/15 min 10 (+10-100)

longan powder dry 500 MPa/30°C 100

onion dry 100-400 MPa/5-50°C/5 min 12

strawberry puree wet 600 MPa/30°C/15 min 10

tomato puree wet 600 MPa/20°C/15 min 0

Microwave – Summary of Vitamin Effects

• Few papers on Vitamins A and B.• Vitamin C papers focus on f/v pieces,

only 1 paper on orange juice. • Microwave processing generally less

damaging than thermal to Vitamin C. • Exception – OJ lower in Vit C with MW. • MW drying resulted in higher Vit C than

traditional air drying.

MW – Summary of Specific Effects• Total phenolics retained better in MW f/v

pieces if MW power not too high.• Freeze dry >MW vacuum dry > air dry

for total phenolics. • MW f/v retained as much

or > carotenoids than fresh or frozen. • Mineral content similar in sun and MW dry.• Fiber retention fairly good in MW dry.

2012 Microwave – Vitamins A, B, CVitamin

Commodity and Product

Wet vs Dry basis Microwave Conditions % Loss % Gain

Range % Loss or (Gain)

VITAMIN A            apricots wet 50-60 Hz, 50-160°C ~250 (+260)

VITAMIN B1            (thiamin) swiss chard wet no information 60 32-60

green beans wet no information 32VITAMIN B2            

(riboflavin) swiss chard wet no information 9 9 to 47green beans wet no information 47

VITAMIN C            

apple puree wet 2450 MHz, 652 W, 15-60°C, 35 s 570-57 (+10-

260) apricots wet 50-60 Hz, 50-160°C ~260broccoli wet 700 W, 9 min 0brussels sprouts wet 700 W, 5 min, 74°C 10 to 15carrots wet 700 W, 9 min 120-130carrots wet 2450 MHz, 4 kW, 50°C 35green beans wet 700 W, 9 min 117orange juice wet 245-455 W, 0.5-15 min, 100-125°C 30-50peas wet 750 W, 2 min 13spinach wet 750 W, 2.t min 106tomatoes wet 700 W, 4 min 10

2012 Microwave - CarotenoidsCAROTENOIDS

Commodity and Product

Wet vs Dry basis Microwave Conditions % Loss % Gain

Range % Loss or (Gain)

β-carotene carrots wet 1000 W, 60°C-90 min or 90°C-4 min 0 0-75

carrots wet 2450 MHz, 4 kW, 50°C 30

kiwi puree wet 2450 Mz, 285, 570 and 850 W, 15-60 s 75

chlorophyll brussels sprouts wet 700 W, 5 min, 74°C 8 8 to 75

kiwi puree wet 2450 Mz, 285, 570 and 850 W, 15-60 s 25-75

lycopene cherry tomatoes wet 1-33 W/gram, 40-80°C 86 86

Total Carotenoids papaya puree wet 2450 Mz, 285, 570 and 850 W, 15-60 s 0 to 57 0-57

2012 Microwave - PhenolicsPHENOLICS            

rutin asparagus wet 915 MHz, 121°C, 3 min 0 0protocatechuic acid unpeeled potato wet 2450 MZ, 150-1000 W, 95-420 min 14 to 26 14-84

peeled potato wet 2450 MZ, 150-1000 W, 95-420 min 50 to 84caffeoylquinic acid unpeeled potato wet 2450 MZ, 150-1000 W, 95-420 min 6 to 60 6 to 65

peeled potato wet 2450 MZ, 150-1000 W, 95-420 min 23 to 65pelargonidin-3-

glucosides strawberry puree wet 2450 Mz, 285, 570 and 850 W, 15-60 s 0 0Total anthocyanins

kiwi puree wet 2450 Mz, 285, 570 and 850 W, 15-60 sstrawberry puree wet 2450 Mz, 285, 570 and 850 W, 15-60 s 0sweet potato wet 915 kW, 5 kW and 60 kW 15

Total flavonoidsbrussels sprouts wet 700 W, 5 min, 74°C 15 15

Total phenolics

apple puree wet 2450 Mz, 652 W, 75°C, 35 sec 570-57 (+104-

125)carrots dry 800 W, 6 min 125cauliflower dry 800 W, 8 min 114peas dry 800 W, 5.5 min 39potato dry 800 W, 6.5 min 107potato wet 2450 MZ, 150-1000 W, 95-420 min 4 to 32spinach dry 800 W, 6.5 min 42sweet potato wet 915 kW, 5 kW and 60 kW 105-108Swiss chard dry 800 W, 6.5 min 86tomato dry 800 W, 3 min 91

2015 JAFC Publications

Fresh and FrozenFruits and Vegetables

Ali Bouzari, PhD Candidate

Experimental Design

6 field replicates

Commodities

• Carrots August 2012• Spinach December 2012• Broccoli February 2013• Blueberries March 2013• Peas April-May 2013• Green Beans June 2013• Strawberries July 2013• Corn August 2013

Ascorbic Acid

• Fresh storage: Blueberries, green beans, and corn lost AA

• Frozen storage: No losses • Higher*: blueberries, green beans, and corn• Same as fresh: strawberries, carrots, peas,

spinach, broccoli• Lower: none

• *Blanched + Frozen Day 90 vs. Fresh Day 10

Ascorbic Acid – Strawberries

0 3 10 90400

420

440

460

480

500

520

540

AB

B

AB

B

B

A

Fresh Frozen

Days

Asc

orb

ic A

cid

(p

pm

)

Ascorbic Acid – Green Beans

0 3 10 90 0

200

400

600

800

1000

1200

B

C

D

AB A AB

Fresh Frozen

Days

Asc

orb

ic A

cid

(p

pm

)

b

Riboflavin

• Fresh storage: Increases in corn and broccoli

• Frozen storage: Losses in peas• Higher : Broccoli• Same as fresh: Carrots, corn, green beans,

broccoli, blueberries, strawberries• Lower: Peas

Riboflavin – Green beans

0 3 10 90 5.60

5.80

6.00

6.20

6.40

6.60

6.80

A

A

AA

A

A

Fresh Frozen

Days

Rib

ofla

vin

(p

pm

)

Riboflavin – Peas

0 3 10 90 0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

A A AA A

B

Fresh Frozen

Days

Rib

ofla

vin

(p

pm

)

Alpha Tocopherol

• Fresh storage: Losses in peas, carrots A, corn• Frozen storage: Losses in broccoli, carrots B• Higher: peas, green beans, spinach

blueberries, corn (blanching releases?)• Same as fresh: broccoli, carrots B, and

strawberries• Lower: None

Alpha Tocopherol – Peas

0 3 10 90 0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

BBC

C

A A A

Fresh Frozen

Days

Alp

ha

Toc

oph

erol

(p

pm

)

b

Alpha Tocopherol – Broccoli

0 3 10 90 0.00

50.00

100.00

150.00

200.00

250.00

C C

B

A

B B

Fresh Frozen

Days

Alp

ha

Toc

oph

erol

(p

pm

)

Beta Carotene

• Not found in blueberries, strawberries, and corn• Fresh storage: Losses in peas, green beans,

and carrots• Frozen storage: Losses in peas, spinach, and

carrots• Higher: None• Same as fresh: green beans and broccoli• Lower: peas, spinach, and carrots

Beta Carotene – Carrots

0 3 10 90 0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.0

AAB

BCCD

D

E

Fresh Frozen

Days

β-ca

rote

ne

(pp

m)

a

Beta Carotene – Green beans

0 3 10 90 0.0

5.0

10.0

15.0

20.0

25.0

B B

AA

AA

Fresh Frozen

Days

Bet

a C

arot

ene

(pp

m)

Fiber

• Fresh storage: Increase in broccoli• Frozen storage: Losses in carrots• Higher: none• Same as fresh: blueberries, strawberries,

spinach, and corn• Lower: carrots, peas, green beans, broccoli

Fiber - Blueberries

0 3 10 90 5.8

6.0

6.2

6.4

6.6

6.8

7.0

7.2

AA

AB

BCC

AB

Fresh Frozen

Days

Fib

er (

%)

Fiber - Broccoli

0 3 10 90 0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

B B

A

B BB

Fresh Frozen

Days

Fib

er (

%)

a

Phenolics

• Fresh storage: Increases in peas, spinach, and broccoli; losses in carrots and corn.

• Frozen storage: Losses in peas, carrots, and corn

• Higher: blueberries• Same as fresh: spinach, green beans,

carrots• Lower: broccoli, corn, peas

Phenolics - Spinach

0 3 10 90 0.00

2.00

4.00

6.00

8.00

10.00

12.00

B

A AB

A A

Fresh Frozen

Days

Tot

al P

hen

olic

s (m

g G

AE

/g)

Phenolics – Corn

0 3 10 90 0.00

0.50

1.00

1.50

2.00

2.50

3.00

AA

B

AA

C

Fresh Frozen

Days

Tot

al P

hen

olic

s (m

g G

AE

/g)

b

Minerals

• Minerals can only be lost during blanching• Most commodities retained minerals well

• Slight losses in magnesium• Iron losses most significant

Conclusions• For most nutrients, frozen presents a viable

alternative to fresh.• Riboflavin, alpha tocopherol, ascorbic acid and

minerals were well conserved and at times their content was higher in blanched and frozen stored fruits & vegetables than in fresh stored produce.

• Fiber and phenolics content in frozen stored produce were similar to fresh in some commodities.

• Beta carotene was least well conserved in blanched and frozen stored fruits & vegetables.

• Follow up studies on effects of food preparation in the home are recommended.

Thanks for your attention!