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Semelhante a Oxidation, Antioxidants and Their Role in Food Preservation
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Oxidation, Antioxidants and Their Role in Food Preservation
- 1. Presented by: Mr. Prasanna Prakash Bhalerao M.Tech 2nd yr North Maharashtra University, Jalgaon.
- 2. Introduction Oxidation: chemical reaction that involves transfer of electrons from one compound to other. Contributes to diseases such as cancer, heart disease. Oxidation causes loss of flavour and colour in foods. To prevent oxidation antioxidants are used.
- 3. Free Radicals “any species capable of independent existent that contains one or more unpaired electrons” Example : Radicals can be formed by… 1. The LOSS of a single electron from a non-radical, or by the GAIN of a single electron by a non-radical 2. The breakage of covalent bond ‘homolytic fission’ A B A + B H2O H + OH Example : Hydroxyl radical ( OH)O H
- 4. Free Radicals and Diseases Cancer Inflammation/Infection Ischemia-reperfusion injury Neurodegenerative diseases Cardiovascular diseases Aging Others (e.g., drug/chemical-induced toxicity, etc)
- 5. Lipid Peroxidation 1. Initiation of first-chain reaction • Abstraction of H+ by ROS (• OH) • Formation of lipid radical (LH• ) • Formation of peroxyl radical (LOO• , ROO• ) 2. Propagation • H+ abstraction by lipid peroxyl radical (LOO• ) 3. Termination • Radical interaction non-radical product
- 6. • Molecular rearrangement Conjugated diene Lipid hydroperoxide Cyclic peroxide Cyclic endoperoxide • •-H Hydrogen abstraction I • O O O O H •H O2 Oxygen uptake Peroxy radical: abstract H• rom another fatty acid causing an autocatalytic chain reactions P I P Initiation Propagation (LH•) (LOO•)
- 7. Antioxidants Antioxidants are the compounds that prevent oxidation. They delay autoxidation by inhibiting formation of free radicals They prevent oxidation by donating electrons from their hydroxyl [-OH] group Free radical binds with hydroxyl group and result in stable double bond
- 8. Methods of producing stable foods without adding antioxidants Technique Method Elimination of oxygen Packaging under nitrogen, Packaging with vacuum Packaging with oxygen scavenger Elimination of sensitive substances Replacement of polyunsaturated oil with oils which are less unsaturated and more stable such as olive oil or palm oil
- 9. Decreasing the rate of oxidation Storage at low temperature Storage in dark Use of fats and oils that contains oxidised products and heavy metals. Use of ingredients that are naturally rich in antioxidants
- 10. Inhibiting oxidation 1. Minimize influence of physical factors (air, light, higher temperature) during processing and storage. 2. Inhibit autoxidation: chain breaking and preventive inhibitor.
- 11. Chain breaking antioxidants Chain breaking antioxidant radical AH scavenge free radical (LOO*, LO*) and forming antioxidant radical A* LOO* + AH LOOH + A* LO* + AH LOH + A*
- 12. Antioxidant class Mechanism Examples Proper antioxidants Inactivating lipid free radicals Phenolic compounds Hydroperoxide stabilizers Preventing decomposition of hydroperoxides into free radicals Phenolic compounds Synergists Promoting activity of proper antioxidants Citric acid, ascorbic acid
- 13. Metal chelators Binding heavy metals into inactive compounds Phosphoric acid, Maillard compounds, citric acid Singlet oxygen quenchers Transforming singlet oxygen into triplet oxygen Carotenes Substances reducing hydroperoxides Reducing hydroperoxides in a non-radical way Proteins, amino acids
- 15. Natural antioxidants. Ascorbic acid Vitamin E β-carotene Flavonoid Anthocyanin Polyphenols
- 16. Natural antioxidants Compound Source Vitamin C Citrus fruits Vitamin E (Tocopherol) Cereal grains, oil, green vegetables β-carotene Carrot, papaya Flavonoids Tea, red wine, vegetables Anthocyanin High in Red wine, blueberry, blackberry, Polyphenols Tea, grape juice Lycopene Tomato, watermelon etc coQ10 Wheat bran, fish.
- 17. BENEFITS OF NATURAL ANTIOXIDANTS Antioxidant Benefits Mode of action Vitamin C Prevents Cancer and heart disease Inhibits oxidation of DNA Tocopherol/ Vitamin E Prevents oxidation of lipids Passed through liver and delivered to adipose (fat) tissue. Vitamin A Prevents oxidation Passed through liver and deposited in adipose tissue
- 18. BENEFITS OF NATURAL ANTIOXIDANTS CONTD….. Lycopene Retards cancer formation Binds with surface membrane protein of damaged cells Polyphenols Prevents build up of plaques Prevents oxidation of LDL molecules.
- 19. Classification of antioxidants Antioxidants Synthetic Priamary Secondary NaturalNatural
- 20. Ascorbic acidAntioxidant function: Donate e- quenches free radical, and generating double bond.
- 21. β-carotene, Lycopene, Vitamin A Antioxidant function: Donates double bond to prevent oxidation
- 22. Radical terminator: (BHA, BHT, TBHQ, PG, DG, OG) Antioxidant function: Transfer of e- from phenol group.
- 24. Cellular Defense Mechanisms Isolation of generation sites of reactive oxygen species Inhibition of propagation phase of reactive oxygen species Scavenging of reactive oxygen species Repair of the damage caused by reactive oxygen species
- 25. Natural and synthetic antioxidants Synthetic antioxidants Natural antioxidants Inexpensive Expensive Widely applied Use restricted to some products Medium to high antioxidant activity Wide ranging antioxidant activity Increasing safety concern Perceived as innocuous substance Use banned for some of them Increasing use and expanding applications Low water solubility Broad range of solubility Decreasing interest Increasing interest
- 26. Laws and regulations for antioxidants Food item Antioxidants Specification Bread and biscuit Ascorbic acid GMP Snacks and sweets BHA TBHQ 200 ppm max Chewing gum BHA 250 ppm max Carbonated water TBHQ BHA 0.01 % max Oil and fats Ascorbic acid, PG, OG, DG BHA TBHQ 100 ppm max 200 ppm max 200 ppm max Frozen fish Sodium and pottasium ascorbic acid 1 gm/kg
- 27. FDA Specifications. Compound name Limits Use BHA Less than 200 mg/kg Cereals, chewing gums, vegetable oil, bakery products BHT Less than 100 mg/kg Cereals, chewing gums, bakery, beverages PG, OG, DG Less than 200 mg/kg Vegetable oil, snacks, confectionary EDTA - Salads, processed fruits and
- 28. BHA Hypertrophy of liver, lung proliferation BHT Cell proliferation PG Damage to heart
- 29. Future trends Develop products susceptible to lipid oxidation. Improving Methods of preventing oxidative detoriation. Develop novel antioxidants which are stable at all processing conditions. Develop new antioxidant from natural sources.
- 30. Conclusion Antioxidants provide several beneficial health benefits, they also have potential toxic effects if not consumed in proper fashion. Antioxidants as functional foods.
- 31. References Abuja P M et al. (1998), ‘Antioxidant and prooxidant activities of elderberry (Sambucusnigra) extract in low-density lipoprotein oxidation’, J Agric Food Chem, 46,4091–4096. AlSaikhan M. S. (1995), ‘Antioxidant activity and total phenolics in different genotypes of potato (SolanumtuberosumL)’, J FoodSci, 60. Brewer M.S (2011), ‘Natural Antioxidants: Sources, Compounds, Mechanisms of Action, and Potential Applications’, Comprehensive Reviews in Food Science and Food Safety, 10, 221-248. Brieskorn C H and Domling H-J (1969), ‘Carnosolsäure, der wichtigeantioxidativwirksameInhaltsstoff des Rosmarin- und Salbeiblattes’, Z LebensmittelUntersuchForsch, 141,10–16.
- 32. References contd….. Frank M.D (2005), ‘A Review of Antioxidants and Alzheimer’s Disease’, Annals of Clinical Psychiatry, 17, 269–286. Frankel E N (1998), ‘Lipid Oxidation’, Dundee, The Oily Press. Gardner H W, (1989), ‘Oxygen radical chemistry of polyunsaturated fatty acids’, Free Rad. Biol Med, 7, 65–86. Linde H (1964), ‘EinneuesDiterpenausSalvia officinalisL und eineNotizzurKonstitution von Pikrosalvin’, HelvChimActa, 1361234– 1239. Lolinger J (1991), ‘The use of antioxidants in foods’, in: Free Radicals and Food Additives, Madhavi D L et al. (1996), ‘Food Antioxidants’, New York, Marcel Dekker. Meyer A.S et al.(1997) ‘Inhibition of human low-density lipoprotein oxidation in relation to composition of phenolic antioxidants in grapes (Vitisvinifera)’, J Agric Food Chem, 45, 1638–43.
- 33. Contd………… Msagati Titus A. M. (2013) ‘Chemistry of Food Additives and Preservatives’, Chemistry of Food Additives and Preservatives, First Edition, John Wiley & Sons, Ltd. Page 1-32. Nakatani N and Inatani R (1981), ‘Structure of rosmanol a new antioxidant from rosemary (RosmarinusofficinalisL)’, AgricBiolChem, 452385–2386. Nawar W. W. (1985), ‘Lipids in Food Chemistry’, Fenema O R (ed.), New York, Marcel. Neff W E et al., (1994), ‘Oxidative stability of purified canola oil triacylglycerols with altered fatty acid compositions as affected by triacylglycerol composition and structure’, J Amer OilChemSoc, 71 1101. Noguchi N et al. (1999), ‘Chemistry of active oxygen species and antioxidants’, in: Antioxidant Status, Diet, Nutrition and Health, Papas A M (ed.), Boca Raton, CRC Press, page, 3–20. Onyeneho S N and Hettiaranchchy N S (1993), ‘Antioxidant activity, fatty acid and phenolic acid compositions of potato peels’, J Sci Food Agric, 62, 345–350. Podsedek A, (2007), ‘Natural antioxidants and antioxidant capacity of Brassica vegetables: A review’, LWT, 40, 1–11. Pokorny J (1991), ‘Natural antioxidants for food use’, Trends in Food SciTechnol, 223–227. Prabhasankar P and Nanditha B (2009), ‘Antioxidants in Bakery Products: A Review’,Critical Reviews in Food Science and Nutrition, 49, 1–27.
- 34. Contd…. Robards K, (1987), ‘Analytical Chemistry of Synthetic Food AntioxidantsA Review’, ANALYST, 112, 933- 943. Schyvens C, (2014), ‘Antioxidants’, Encyclopedia of Food Safety, 455-458. Seifried H.E (2007), ‘A review of the interaction among dietary antioxidants and reactive oxygen species’ Journal of Nutritional Biochemistry, 18, 567–579. Simic M G et al. (1992), ‘Mechanism of lipid oxidative processes and their inhibition’, in: Lipid Oxidation in Food,ACS Symposium Series, No 500, St Angelo A J (ed.), Washington, ACS Press, page 14–32. Sindhi V et al. (2013), ‘Potential applications of antioxidants: A review’ Journal of pharmacy research, 7, 828-835. Tamura H and Yamagami A (1994), ‘Antioxidant activity of monoacylatedanthocyanins isolated from Muscat Bailey A grape’, J Agric Food Chem, 42, 1612–1615. Valenzuela A et al. (1996), ‘Synthetic and natural antioxidants: food quality protectors’, Grasas y Aceites, 47, 86–96.
- 35. THANK YOU………..