多酚是一类天然存在的抗氧化物质,大量研究表明摄入多酚可降低许多疾病的发生风险。然而富含多酚的食物常与牛乳一同食用,已有研究表明牛乳会抑制多酚的体内吸收,但牛乳中各成分在这一影响中所起的作用及相关机制尚不明确,因此本研究以市场占有率很高的"枣汁奶"为研究模型,主要评价了牛乳不同成分对枣多酚抗氧化活性的影响。结果表明:添加全脂乳或脱脂乳均显著抑制枣多酚的抗氧化活性,而牛乳超滤液(主要成分为牛乳中的碳水化合物和小分子物质)则无影响。经胃肠消化酶消化后,脱脂乳抑制抗氧化活性的作用减弱,而全脂乳仍保持较强的抑制作用,表明在消化过程中脂肪的存在会影响枣多酚的抗氧化活性。

Polyphenol is a natural antioxidant and it can reduce the risk of many diseases by studies. While polyphenol-rich foods are usually consumed with milk,some studies have shown that milk can reduce the bioavailability of polyphenols. However,little is known about the roles of milk components in this inhibitory effect. Therefore,we chose "jujube-milk juice"as a research model studying the effect of different milk components on the antioxidant activity of jujube polyphenols. In addition,the effect of digestive enzymes on the interactions between milk and jujube polyphenols was also investigated. The results showed that whole milk or skimmed milk significantly inhibit the antioxidant activity of jujube juice. After in vitro digestion,the effect of skimmed milk on the antioxidant activity of jujube polyphenols was weakened,but whole milk still maintain a strong inhibitory effect,indicating the presence of fat affects the antioxidant activity of jujube polyphenols during digestion.