Protections against photooxidation of milk by a high urate content

Summary

Differences of susceptibility to light induced oxidation in milk with a low or high content of urate was studied. The natural urate content of the cows milk was manipulated by different feeding regimes. It was found that milk with a high content of urate was less prone to photo-induced lipid - and protein oxidation measured as the formation of lipid hydroperoxides and dityrosine, respectively. It is suggested that urate reacts directly with sensitized riboflavin and/or by reaction with singlet oxygen.
The overall conclusion is that it is possible to improve the antioxidative capacity of milk by increasing the natural urate content through strategic feeding of the dairy cow.