ANTIOXIDANT ACTIVITY OF RAW MILK AND MILK PROTEIN FRACTIONS

Abstract

Compounds with antioxidant properties act as stabilizers of biological membranes and prevent the development of free-radical chain processes that lead to the development of severe diseases. Cow’s milk shows antioxidant activity due to whey proteins. Heat treatment used in dairy production technology can inhibit the antioxidant properties of milk proteins. Preserving the natural properties of milk is an urgent task. (Research purpose) The research purpose is in studying the antioxidant activity of raw milk and protein fractions isolated from it with optimal preservation of the activity of whey proteins. (Materials and methods) Authors received raw milk from an individual farm in the Moscow region. The physicochemical parameters of milk and whey were assessed by standardized methods; the fractional composition of proteins was assessed by high-performance liquid chromatography; and the antioxidant activity (total content of water-soluble antioxidants) of milk and protein fractions isolated from it assessed by amperometric method. Milk proteins were coagulated using rennet and calcium chloride. Protein fractions were separated by centrifugation (15,000 revolutions per minute) for 90 minutes. (Results and discussion) The article presents the physical and chemical parameters of raw whole and skimmed milk. The fractional composition of native serum proteins with a predominance of beta-lactoglobulin was studied. The method of milk protein isolation by rennet-calcium method was worked out at a minimum temperature of 38-40 degrees Celsius. (Conclusions) The article presents the composition of raw milk. The article presents the developed optimal conditions for isolation of native proteins from raw skim milk. The antioxidant activity of raw milk, casein fraction and whey was assessed. To maximize the preservation of the antioxidant activity of biologically active whey proteins, it is necessary to reduce the generally accepted pasteurization temperatures of milk (75-95 degrees Celsius), while at the same time searching for new methods of decontamination of milk from foreign microflora.