Assessment of the level of oxidative modification of proteins adapted milk mixtures

Background.Recently, the determination of the level of carbonyl derivatives has been used in the study of food products. However, to increase sensitivity and specificity, it is necessary to compare different criteria for oxidative damage to milk proteins. The purposeof the study is to compare the informative significance of indicators of the intensity of oxidative destruction of proteins of various adapted milk mixtures. Materials and methods.Various adapted milk mixtures based on cow's and goat's milk were used as the material. To assess the level of protein carbonyl derivatives, the Reznick A.Z. Parker L. method and the method of complex assessment of the content of carbonyl derivatives, with the calculation of the reserve potential were used (Fomina M.A. et al. 2014). Results.The calculation of the reserve potential (RP), carried out after the determination of spontaneous and iron-induced oxidation, made it possible to establish its increase (by 5-10%) in all dairy mixtures based on cow's milk in comparison with ultrapasteurized milk. An increase in the overall level of reserve potential is manifested by aldehyde-dinitrophenylhydrazones.A similar increase in the overall level of reserve potential is observed in adapted milk mixtures made on the basis of goat's milk in comparison with the indicator of ultra-pasteurized milk. Differences in the ratio of aldehyde and ketone derivatives in adapted milk mixtures 1 and 2 based on cow's milk and in goat's milk mixtures have been established. Conclusion.The determination of the reserve potential made it possible to identify adapted milk mixtures with the highest and lowest levels of this indicator, characterizing the resistance of proteins to the effects of the usual level of oxidants, for additional characteristics of the biological value of the product.