Antioxidative Activity of Urate in Bovine Milk

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• 作者：Henrik Ø ; stdal ; Henrik J. Andersen ; and Jacob H. Nielsen
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2000
• 出版时间：November 2000
• 年：2000
• 卷：48
• 期：11
• 页码：5588 - 5592
• 全文大小：56K
• 年卷期：v.48,no.11(November 2000)
• ISSN：1520-5118

文摘

The antioxidative effects of urate on peroxidase-induced protein oxidation and light-induced riboflavindegradation and lipid oxidation in whole milk were studied. In addition, experiments using ascorbatewere conducted to directly compare the antioxidative activity of urate and ascorbate. The presenceof urate and/or ascorbate (10-30 mg/L) lowered peroxidase-induced formation of dityrosine by 44-96% in unpasteurized whole milk. No synergistic effect of urate and ascorbate on peroxidase-induceddityrosine formation was registered, but merely an additive effect. Light exposure of pasteurizedwhole milk showed that ascorbate was oxidized at the expense of urate, which indicated ascorbate-mediated recycling of the urate radical. Moreover, both urate and ascorbate (30 mg/L) retardedlight-induced lipid oxidation in pasteurized whole milk as measured by formation of lipidhydroperoxides with urate being the most effective (28% reduction in lipid hydroperoxides) comparedwith ascorbate (14%). Finally, addition of urate or ascorbate (300 mg/L) to pasteurized whole milkshowed a slight protective effect against light-induced degradation of riboflavin with urate beingthe most effective.Keywords: Uric acid (urate); ascorbic acid (ascorbate); milk; dityrosine; lactoperoxidase; fluorescentlight; riboflavin; lipid hydroperoxides