Dairy antioxidant system

A review of dairy antioxidants was done based on local and international sources. Oxidative processes of fat are the main cause of chemical spoilage of milk and dairy products. Lipid oxidation is associated mainly with the amount of unsaturated fatty acids in the shells of fat globules and plasma phospholipids, as well as with the amount of free fat. The products of oxidative reactions at different stages of lipid oxidation with atmospheric oxygen are fatty acid hydroperoxides, peroxides, aldehydes, ketones, hydroxy acidswhich not only worsen the organoleptic characteristics of milk, but some of them are toxic substances. The antioxidant ability of milk is due to vitamins A, C, E, carotenoids, enzymes, lactoferin, sulfur-containing amino acids. One of the most powerful natural antioxidants is ascorbic acid, which is able to absorb superoxide anion radicals, alkoxyl radicals, superoxide, iron oxide, nitric oxide. Group E vitaminsare described, being the primary fat-soluble antioxidants. Among this group of substances, the most biologically active form is ?-tocopherol. The contribution of carotenoids to antioxidant protection has been determined. Beta carotene is considered as a preventive antioxidant, as it can block singlet oxygen which ishighly toxic. The mechanisms of antioxidant action of various enzymes are disclosed. Xanthioxidase has been shown to oxidize various aldigides and purine bases to the corresponding acids. Lactoperoxidase catalyzes the oxidation of thiocyanate with hydrogen peroxide to form thiociagen. Catalase oxidizes hydrogen peroxide to form water and molecular oxygen. Glutathione peroxidase is capable of rapidly removing hydrogen peroxide and other peroxides. The mechanism of the antioxidant action of lactoferrin is described which is based on iron the chelation by it. The functions of sulfur-containing amino acids due to the binding of free radicals are disclosed. Determining the total antioxidant activity can be a biomarker of its biological value, which will allow to choose the most perspective areas of milk processing..