Oxidative stability of milk fat in respect to its chemical composition

The oxidative stability of milk fat from non-pasteurised sweet cream was examined over a 24-month period with respect to the fatty acid composition, and β-carotene, vitamin A, α-tocopherol and phospholipid contents. The oxidative stability of milk fat was significantly higher during the period of pasture feeding of cows compared with the stall feeding period. Positive correlations were reported between the oxidative stability index and contents of fat-soluble vitamins and phospholipids in milk fat. An equation developed from a multiple regression analysis with step-wise elimination of variables indicated that the oxidative stability of milk fat was affected to the greatest extent by the contents of α-tocopherol, β-carotene, C18:1 cis and trans acids and conjugated linoleic acid.