Improvement of quality and nutritional value of muscle foods

Food is an essential to our existence but under certain conditions it could become the origin to the accumulative health damages. Technological processes as heating, chopping, mincing, grounding, promote the lipid oxidation process in muscle tissues and meat foodstuffs. Lipid oxidation occurred rapidly in turkey muscle, intermediate in duck, and slowest in chicken during frozen storage. Depletion of tocopherol during frozen storage was more rapid in turkey and duck compared to chicken. These processes developed from lipid peroxides produce many cytotoxic compounds including malondialdehyde (MDA). The muscle tissue is further oxidized in stomach conditions producing additional cytotoxic compounds. Oxidized lipids that are formed during digestion of a meal possess the potential to promote reactions that incur vascular diseases. A grape seed extract (1% of the meat weight) and butylated hydroxytoluene (0.2% of the lipid weight) were each effective at preventing formation of lipid oxidation products for 3 hours during co-incubation with cooked turkey meat in simulated gastric fluid (SGF). Polyphenols in the human diet, as an integral part of the meal prevent the generation and absorption of cytotoxic compounds and the destruction of essential nutrients, eg. antioxidants vitamins during the meal. Polyphenols act as antioxidants in the gastrointestinal tract; they scavenge free radicals and may interact with reactive carbonyls, enzymes and proteins. These all reactions results in decreasing the absorption of reactive carbonyls and possible other cytotoxic compounds into the plasma. Consumptions of diet high in fat and red meat are contributory risk factors partly due to an increase production of cytotoxic oxidized lipid products eg. MDA. However, the simultaneously consumption of polyphenols rich foods reduce these factors. Locating the biological site of action of polyphenols in the in the gastrointestinal tract may explain the paradox between the protective effect of a highly polyphenols rich diet and the low bioavailability of these molecules in human plasma. It may also explain the "French paradox" and the beneficial effect of Mediterranean and Japanese diets, in which food products with high antioxidants content such as polyphenols are consumed during the meal.