Intensity of lipid peroxidation and protein oxidative modification of goat and cow milk
AbstractIndices of free-radical peroxidation have been estimated: intensity of lipid peroxidation and protein oxidative modification of goat and cow milk of specific breeds of forest-steppe zone of Omsk region. The obtained results indicate that processes of lipid peroxidation and protein oxidative destruction in goat and cow milk of different breeds occur with different gradation. The content of carbonile derivatives in goat milk of Saan breed 1,4 (0,95; 1,5) u/ml was lower than in cow’s milk of black-and-white breed 4,6 (1,1; 6,0) u/ml (p=0,005) what could be caused by large content of protein thiol groups of this kind of milk and lower quantity of amino acid residues that are available for carbonylation. This kind of milk is characterized by higher SH-group content than cow milk for 31% and Switzerland goat milk for 20% (р=0,005). The content of cetodiens and attached triens in isopropanol phase of the lipid extract of goat milk of Swiss breed is lower by 30% than in cow milk. In isopropanol phase of the milk lipid extracts containing phospholipids the level of Schiff grounding did not differ. The results obtained prove that goat milk contain less protein subjected to oxidative modification
Keywords:lipid peroxidation, milk, goat milk, oxidative modification of proteins, sulfhydryl groups