Interrelationships of antioxidant activity and the main parameters of milk of Holstein cows during its pasteurization

Abstract

Milk is a very important food product for humans and young animals of some farm animals. The aim of the work is to comparatively study such an integral indicator as the total amount of water-soluble antioxidants (TAWSA) before and after pasteurization of milk of Holstein cows with the analysis of details of these changes and comparison with the biochemical profile. The pasteurization studies were carried out according to industrial technological regulations (at 72°C for 15 seconds) with milk samples of cows of the Ladozhskoye breeding farm. Each of the 6 formed groups included 22 heads of cows, which is enough for statistical analysis. A significant increase in TAWSA values was found in pasteurized milk samples to the maximum values of 24.3 mg/l in group 1 (avg. milk yield 16.6 l) and 25.4 mg/l in group 2 (avg. milk yield 30.2 l); up to 25.9 mg/l in group 3 (MDF 3.50%) and 24.0 mg/l in group 4 (MDF 4.62%); up to 26.0 mg/l in group 5 (MDPt and MDPg 3.09% and 3.24%) and 23.7 mg/l in group 6 (MDPt and MDPg 4.31% and 4.34%) compared to the control before pasteurization. These significant differences are associated (both in our opinion and according to literature data) with a certain degree of protein denaturation and oxidation of milk lipids, which makes a number of functional groups of these milk components more accessible to oxidationreduction processes recorded by the amperometric method as TAWSA. The range of average SCWA values of milk after pasteurization (from 22 to 26 mg/l) can serve as a "reference" interval for practical use. Thus, the analysis of TAWSA changes during pasteurization of cow's milk indicates that the antioxidant activity of milk increases significantly after pasteurization. This is a positive trend for practice in terms of high milk quality after its traditional processing.