Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Box 7023, 750 07 Uppsala, Sweden.
J Dairy Res. 2010 Aug;77(3):302-9. doi: 10.1017/S0022029910000300. Epub 2010 Jun 9.
The oxidative process in milk fat, resulting in spontaneous oxidized off-flavour (SOF), is commonly assumed to depend on contents of pro- and antioxidants in milk and availability of fatty acids acting as their substrate. An important antioxidant in milk is alpha-tocopherol whereas the most potent prooxidant is the metal ion copper. The separate effects of alpha-tocopherol, copper, and milk fatty acid profile, and their combined effect on SOF development were examined in milk from 44 multiparous cows fed different roughage types and different amounts of dietary, unsaturated fat. A clear association between concentrations of copper and poly-unsaturated fatty acids in milk and the risk for developing SOF was found. Heritability estimates suggest that occurrence of SOF is partly under genetic control which indicates that milk quality may be compromised if breeding bulls are selected that carry genotypes predisposing for milk prone to develop SOF.
牛奶脂肪的氧化过程会导致自发氧化异味（SOF），通常认为这取决于牛奶中前体和抗氧化剂的含量以及作为其底物的脂肪酸的可用性。牛奶中的一种重要抗氧化剂是α-生育酚，而最有效的促氧化剂是金属离子铜。在来自 44 头经不同粗饲料和不同量不饱和脂肪饲养的经产奶牛的牛奶中，分别研究了 α-生育酚、铜和牛奶脂肪酸谱及其对 SOF 发展的综合影响。发现牛奶中铜和多不饱和脂肪酸的浓度与发生 SOF 的风险之间存在明显的关联。遗传力估计表明，SOF 的发生部分受遗传控制，这表明如果选择携带易发生 SOF 的基因型的种公牛进行繁殖，牛奶质量可能会受到影响。
