Presentation on theme: "Efectos de Procesamiento en la Calidad Nutricional de Frutas y Hortalizas Dr. Diane M. Barrett Fruit & Vegetable Products Specialist University of California."— Presentation transcript:
Efectos de Procesamiento en la Calidad Nutricional de Frutas y Hortalizas Dr. Diane M. Barrett Fruit & 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 & Vegetables What’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.
*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 *
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 Folat e Vit CVit ECaKNa (AI) Fiber (AI) RDA/AI (mg/day) 0.801.151.2151.30.4082.51510004.71.530 EAR (mg/day) 0.560.951.011.51.20.3267.512---- RDA = Recommended Daily Allowance (in 1997 these broadened into DRIs) AI = Adequate Intake EAR = Estimated Average Requirement DRI = 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 AVitamin E Vitamin B1Calcium Vitamin B2Potassium Vitamin B3Sodium Vitamin B6Fiber Vitamin B9 (folate) Vitamin C Current nutrition label based on older Reference Daily Intakes.
Fruit & Vegetable Sources - Vitamins & Minerals NutrientEAR RDA/ AI ULUnitTop Sources in Common Measures, USDA Vitamin A6259003000µgcarrotcarrot juice, pumpkinpumpkin Vitamin C75902000mgorange juiceorange juice, grapefruit juice, peachesgrapefruitpeaches Vitamin KNE120NDµgkalekale, collards, spinachcollardsspinach Vitamin B 6 1.11.3100mgfortified cereals, chickpeascerealschickpeas α-Tocopherol (Vitamin E) 12151000mgfortified cereals, tomato paste, sunflower seedstomatosunflower seeds Folate (B 9 )3204001000µg enriched white rice, fortified cereals, enriched cornmealwhite rice cornmeal Molybdenum34452000µglegumeslegumes, grain products, nuts and seeds Niacin (B3)121635mgfortified cereals PotassiumNE4700NDmgtomato paste, orange juice, beet greensbeet greens Riboflavin (B2)1.11.3NDmgspaghettispaghetti with meat sauce Thiamin (B1)1.01.2NDmgfortified cereals USDA National Nutrient Database, SR 23, 2010.
Stability of Nutrients in Processed Foods Source: Klein and Kurilich, HortScience 1998 Nutrient NeutralAcidBasicOxygenLightHeatWater Beta- Carotene SSUSUU Slight sol Vitamin CUSUUUUUU ThiaminUSUUUSUU RiboflavinSSUSUUSU FolateUUSSUSSU MineralsSSSSSSS Vitamin ESSUSUUUSUinsoluble Effect of pHEffect 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 storage 56% 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) Nagarajan et al 1999 Note 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 & B Vitamin Commodity and Product Wet vs Dry basisHigh Pressure Conditions% Loss% GainRange VITAMIN A persimmon pureewet350 MPa/5 min45(+45) VITAMIN B1 (thiamin) model soln & juiceswet400-600 MPa/25°C/30 min0-10 VITAMIN B2 (riboflavin) model soln & juiceswet400-600 MPa/25°C/30 min0-10 VITAMIN B3 (niacin) OJ & seedswet200-500 MPa/30°C/1-10 min00 VITAMIN B5 (pantothenic acid) sprouted alfalfa seedwet500 MPa/25°C/10 min00 VITAMIN B6 (pyridoxal) model soln & juiceswet400-600 MPa/25°C/1-30 min00 VITAMIN B9 (folic acid) model solutionwet400-600 MPa/25°C/5-40 min00-90 various juiceswet500 MPa/20-60°C/40 min0-90
2012 HPP Effects – Vitamin C Vitamin Commodity and Product Wet vs Dry basisHigh Pressure Conditions% Loss% GainRange VITAMIN C buffer solutionwet850/60°C/6 hr100 apple-broccoli juicewet500 MPa/5 min3 apple-broccoli juicewet500 MPa/20 min28 green beans (whole)wet500 MPa/25°C/1 min8 green peas (whole)wet900 MPa/20°C/5-10 min12 green pepperswet100-200 MPa/10-20 min10 to 15 kiwi-strawberry jamwet400-600 MPa/10-30 min0-5 melon pieceswet600 MPa/10 min50-90 orange juicewet100 MPa/60°/5 min10 orange juicewet400 MPa/40°C/1 min5 to 8 orange juicewet350 MPa/30°C/2.5 min0 red pepperswet100-200 MPa/10-20 min10 to 15 strawberry pureewet600 MPa/30°C/15 min6 tomato pureewet400 MPa/40°C/15 min29 tomato pureewet600 MPa/20°C/15 min6
MW Manuscripts – General Remarks No reviews. Only 5/29 manuscripts reported results on a dry weight basis. 15 pertinent manuscripts on microwave 11 on microwave – vacuum drying
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, C Vitamin Commodity and Product Wet vs Dry basisMicrowave Conditions% Loss% Gain Range % Loss or (Gain) VITAMIN A apricotswet50-60 Hz, 50-160°C~250(+260) VITAMIN B1 (thiamin)swiss chardwetno information6032-60 green beanswetno information32 VITAMIN B2 (riboflavin)swiss chardwetno information99 to 47 green beanswetno information47 VITAMIN C apple pureewet2450 MHz, 652 W, 15-60°C, 35 s57 0-57 (+10- 260) apricotswet50-60 Hz, 50-160°C~260 broccoliwet700 W, 9 min0 brussels sproutswet700 W, 5 min, 74°C10 to 15 carrotswet700 W, 9 min120-130 carrotswet2450 MHz, 4 kW, 50°C35 green beanswet700 W, 9 min117 orange juicewet245-455 W, 0.5-15 min, 100-125°C30-50 peaswet750 W, 2 min13 spinachwet750 W, 2.t min106 tomatoeswet700 W, 4 min10
2012 Microwave - Carotenoids CAROTENOIDS Commodity and Product Wet vs Dry basisMicrowave Conditions% Loss% Gain Range % Loss or (Gain) β-carotenecarrotswet1000 W, 60°C-90 min or 90°C-4 min00-75 carrotswet2450 MHz, 4 kW, 50°C30 kiwi pureewet2450 Mz, 285, 570 and 850 W, 15-60 s75 chlorophyllbrussels sproutswet700 W, 5 min, 74°C88 to 75 kiwi pureewet2450 Mz, 285, 570 and 850 W, 15-60 s25-75 lycopenecherry tomatoeswet1-33 W/gram, 40-80°C86 Total Carotenoidspapaya pureewet2450 Mz, 285, 570 and 850 W, 15-60 s0 to 570-57
2012 Microwave - Phenolics PHENOLICS rutinasparaguswet915 MHz, 121°C, 3 min00 protocatechuic acidunpeeled potatowet2450 MZ, 150-1000 W, 95-420 min14 to 2614-84 peeled potatowet2450 MZ, 150-1000 W, 95-420 min50 to 84 caffeoylquinic acidunpeeled potatowet2450 MZ, 150-1000 W, 95-420 min6 to 606 to 65 peeled potatowet2450 MZ, 150-1000 W, 95-420 min23 to 65 pelargonidin-3- glucosidesstrawberry pureewet2450 Mz, 285, 570 and 850 W, 15-60 s00 Total anthocyanins kiwi pureewet2450 Mz, 285, 570 and 850 W, 15-60 s strawberry pureewet2450 Mz, 285, 570 and 850 W, 15-60 s0 sweet potatowet915 kW, 5 kW and 60 kW15 Total flavonoids brussels sproutswet700 W, 5 min, 74°C15 Total phenolics apple pureewet2450 Mz, 652 W, 75°C, 35 sec57 0-57 (+104- 125) carrotsdry800 W, 6 min125 cauliflowerdry800 W, 8 min114 peasdry800 W, 5.5 min39 potatodry800 W, 6.5 min107 potatowet2450 MZ, 150-1000 W, 95-420 min4 to 32 spinachdry800 W, 6.5 min42 sweet potatowet915 kW, 5 kW and 60 kW105-108 Swiss charddry800 W, 6.5 min86 tomatodry800 W, 3 min91
2015 JAFC Publications Fresh and Frozen Fruits and Vegetables Ali Bouzari, PhD Candidate
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
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
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
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
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.