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Nutritional attributes of processed tomato Sudhir Singh Sr. Scientist, IIVR, Varanasi National Scenario India is the second largest producer of vegetables Global share: 13.6 % Agriculture contributes 26.5% of the GDP Diversification in horticulture has resulted in 350% increase in total export of horticultural produce over the last 8 years Export of vegetables – Rs. 1205.35 crores (Fresh – Rs. 467.06, Dried & Preserved – Rs. 738.29) Horticultural crops occupy 8.5% of total cultivated area of India Production and per capita availability of vegetables in India Production Vegetable availability (in gram/head/day) 250 90 80 200 70 60 150 50 40 100 30 20 50 10 0 0 1961 1971 1981 1991 2001 Vegetable availability in gram/head/day Vegetable Production in million tonnes 100 Increasing trends in productivity 18.0 Productivity (t/ha) 16.0 14.9 15.2 15.0 1997-98 1998-99 2000-01 15.8 14.0 12.0 10.5 10.0 8.0 6.0 4.0 2.0 0.0 1991-92 Year 2001-02 Health attributes in vegetables Vitamin A Vitamin C Folic acid Minerals Dietary Fibre- soluble and insoluble Phytochemicals – Carotenoids, Glucosinolate, etc. Phytochemicals Complementary and overlapping mechanism of action including modulation of detoxification enzymes, simulation of immune system, reduction of platelet aggregation. Modulation of cholesterol synthesis, hormone metabolism, reduction of blood pressure, antioxidant, antibacterial and antiviral effects. Phytochemicals – Grains, nuts, legumes, fruits and vegetables Vitamins and minerals in vegetables Good source of vitamin A, vitamin C, folic acid and thiamine Potato and green leafy vegetables – riboflavin Broccoli, cauliflower and tomato – pantothenic acid Spinach, pea, carrot and onion – pyridoxine Vegetables – generally good source of most minerals Green beans and Indian drumstick – rich source of calcium Health attributes of fruits and vegetables The production of fruits and vegetables at annual rate of 5 and 6%, over the last decade. Fresh fruits and vegetables – many health benefits such as reduced incidence of cancers, heart diseases and many chronic diseases of ageing Phytochemicals – anticancer and anti-inflammatory properties Tomato – lycopene pigment associated with decreased risk of cardiovascular diseases Broccoli, Brussels sprout and kale – glucosinolate – low risk of cancer Cont. Garlic and allium – allyl sulphide which inhibit cancer cell growth Dietary flavonoids – inverse correlation with mortality from coronary heart diseases, plasma total cholesterol low density lipoprotein Phytochemicals reduce platelet aggregation modulate cholesterol synthesis and absorption and reduce blood pressure Oxidized LDL – as an antherogenic factor in heart disease, promoting cholesterol ester accumulation Dietary antioxidants from vegetables incorporated into LDL and oxidized themselves thus preventing oxidation of polyunsaturated fatty acids Phytochemicals in vegetables Health promoting properties Presence of relatively low quantities in vegetable crops Non nutrient that have biological activity against chronic diseases Classification of phytochemicals Carotenoids - and -carotene, -cryptoxanthin, lutein, lycopene and zeaxanthin Glucosinolates Sulforaphane, indole-3 carbinol Inositol phosphates Phytate, inositol tetra and penta phosphates Cyclic phenolics Chlorogenic acid, ellagic acid and coumarins Phytoesrerogens Isoflavones, and lignans Phytosterols Campestrol, stigmasterol Phenols Flavanoids daidzenin, genistein -sitsterol and Most common phytochemicals in vegetables Food Phytochemicals Allium vegetables (garlic, onions, chives, leeks) Allyl sulfides Cruciferous vegetables (broccoli, cauliflower, cabbage, brussels sprouts, kale, turnips, bok choy, kohlrabi) Indoles / glucosinolates Sulfaforaphane Isothiocynates / thiocynates, Thiols Solanaceous vegetables (tomatoes, peppers) Lycopene Umbelliferous vegetables (carrots, celery, cilantro, parsley, parsnips) Carotenoids Most common phytochemicals in vegetables Compositae plants (artichoke) Silymarin Citrus fruits (lemons) Monoterpenes (limonene) Other fruits (grapes, berries, cherries, apples, cantaloupe, watermelon, pomegranate) Ellagic acid Phenols Flavonoids (quercetin) Beans, soybeans (protease inhibitors) Flavonoids (Isoflavones) Phytic acid Saponins Gingerols Flavonoids Monoterpenes (limonene) Herbs, spices (ginger, mint, roseberry, thyme, oregano, sage, basil, turmeric, caraway, fennel Antioxidant activity in fresh tomato Vitamin C 160-240 mg/kg Phenolics 10-50 mg/kg Lycopene 5-10 mg/kg Vitamin E 5-20 mg/kg Flavonoids 5-50 mg/kg Pro vitamin Activity Antioxidant Function Xenobiotics Metabolism Immune Response CAROTENOIDS HIV CATARACT CANCER CVD CAROTENOIDS IN DISEASE PREVENTION Processing effect on bioavailability of lycopene Deep red tomato fruits – high concentration of lycopene – processed into products with dark red colour Loss of lycopene – Isomerization and oxidation Isomerization of lycopene – thermal processing Changes in – trans to – cis isomers – biological properties in tomato Determination of degree of isomerization – potential health benefits in processed tomato Oxidation process in tomato- moisture, temperature and presence of autooxidants and lipids Deterioration of red colour in processed tomato products – exposure to air at high temperature thus conversion of all – trans lycopene to be isomerized to cis-lycopene Coupled with exposure to oxygen and light, heat treatments – destruction of lycopene Cont True assessment of nutritional quality and health benefits of processed tomato based products – distribution of lycopene isomers Controlling lycopene isomerization during production and storage- benefit in improving processed tomato products and quality The proportion of all trans lycopene – 96% of total lycopene in preserved tomato paste and 77% in tomato ketchup 20 to 30% of total lycopene – cis-isomers during heating tomato at 100 oC for 1 hr Bioavailability of lycopene in processed tomato juice and paste – significantly hlgher than that from unprocessed fresh tomato Higher retention of lycopene in microwave processed tomato pulp in comparison to those processed by conventional methods Shorter cooking time as compared to longer periods during traditional heating – isomerization and oxidation thus greater lycopene retention in processed tomato products Effect of drying on bioavailability of lycopene Loss of lycopene during drying – important commercial concern Drying of tomato slices – at higher temperature over an extended period under vacuum Tomato pulp – by concentrating in vacuum at lower temperature of 50 oC Tomato powder – spray or roller drying process Formation of cis-isomers – affected by drying methods The different methods of dehydration on lycopene degradation – significant increase in cis-isomers and a simultaneous decrease in all trans-isomers. Cont Osmotically dehydrated tomato – fewer cis-isomers in comparison with directly air dried and vacuum dried tomato Highest amount of cis-isomer in processed tomato samples which increased with temperature and time Osmotic solution remains on the outer layer of tomato thus preventing the penetration of oxygen and minimize the oxidation of lycopene Lycopene degradation in tomato powder – reported 30 and 60% over 6 weeks of storage at 6 and 45 oC, respectively Recent reports – no significant losses of lycopene in tomato samples dried at 80 oC and a maximum of 12% in tomato samples dried at 110 oC Processing effect on bioavailability of -carotene -carotene mainly located in locular cavity than in pericarp tissue Content of -carotene much lower with respect to lycopene in tomato paste than in raw and sliced tomato -carotene more sensitive to oxidative and heat damage than lycopene and partially isomerized and adversely affected during tomato processing Processing effect on carotenoids Combination of fatty acids with carotenoid rich vegetables enhanced carotenoid uptake Bioavailability of lycopene dramatically – by heat treatment in the presence of oil More bioavailability of lycopene in tomato paste than from fresh tomato Processing effect on ascorbic acid Maintenance of higher levels of ascorbic acid received considerable attention by processors Ascorbic acid destruction mainly by oxidation in tomato juice Ascorbic acid oxidation to dehydro-ascorbic acid with further degradation products with no vitamin C activity Oxidation by enzymatic catalyzed by copper ions or non-enzymatic and Cont Longer the period for tomato juice at optimum conditions – the lower the retention of vitamin C Rate of oxidation dependent on dissolved copper and temperature of juice The rate of ascorbic acid destruction - with increase the temperature and in the presence of air Loss of 38% of the original value during hot break extraction at 90 oC for 5-10 min and further 16% loss during concentration (60-70 oC for 4hrs) Ascorbic acid loss 40% in tomato pulp, 55% in tomato puree and 60% in tomato paste Processing effect on phenolics Presence of small amounts of phenolic acids (5-10 mg/kg) in tomato. Epidemiological effects indicate high intake of phenolics and flavonoids correlated with decreased risk of cardiovascular diseases 65% flavonoid present in fresh retained in processed tomato paste The total phenolics content in tomato pulp and puree increased during storage due to release of bound phenolics tomato - Processing effect on antioxidant Dietary lycopene and other antioxidant compounds in tomatoes – potential health promoting properties resulting from their antioxidant activity (AOX) High antioxidant properties attracted the processors to include in various formulated foods The evaluation of total AOX in foods in terms of capacity of substance extracted from food matrix to delay the oxidation process Thermal processing elevated total AOX and bioaccessible lycopene content in tomatoes and produced no significant changes in the total phenolics and total flavonoids content in tomato sauce Besides lypophilic and hydrophilic extract the total AOX was increased Aox of heat treated tomato juice (70 or 95 oC for upto 50 h) resulted in decrease in AOX potential Conclusion Vegetables are rich in vitamins, minerals, folic acid, dietary fibre and certain non-nutrutive phytochemicals having anticancerous and antioxidant activity Ascorbic acid loss 40% in tomato pulp, 55% in tomato puree and 60% in tomato paste Bioavailability of certain carotenoids viz. -carotene, lycopene, phenolics increases after processing of tomato into value added products No significant loss of lycopene in tomato samples dried at 80 oC and a maximum of 12% in tomato samples dried at 110 oC -carotene more sensitive to oxidative and heat damage than lycopene The total phenolics content in tomato pulp and puree increased during storage 65% flavonoid present in fresh tomato- retained in processed tomato paste