ABSTRACT
Natural antioxidants are those phenolic or polyphenolic compounds commonly occurring in plant materials, which interfere with the formation of free radicals (i.e., the initiation reactions) and also deter the propagation of oxidation or the free radical chain reactions, thus preventing formation of hydroperoxides. Free radicals damage the cells of the human body which undergo oxidation with natural oxygen. In general, antioxidants provide primary defense to the bodily system by eliminating free radicals which interfere with metabolism. It is well known that some antioxidants occur naturally in different amounts in all foods and herbal medicines. However, their further addition in small quantities facilitates the delay, retardation, or prevention of the development of rancidity caused by atmospheric oxidation and thus preserves fats, oils, and fat-soluble components like vitamins, carotenoids, and other nutritive ingredients of foods. At higher concentrations, antioxidants may act as pro-oxidants, since they themselves are susceptible to oxidation. Thus, in order to ensure the quality, safety, and shelf-life of food products, it is essential to strictly follow the standards that exist in different countries with respect to the synergy between different classes of food products and antioxidants.
