中文摘要：

采用三聚磷酸钠（STP）对酪蛋白进行磷酸化处理,并用胰蛋白酶进行水解,通过正交试验确定磷酸化处理的最佳条件为：STP添加量为5%,温度为30℃,pH为9.磷酸化时间为3h时,磷酸化程度最高（18.18mg/g）,SDS-PAGE表明酪蛋白谱带发生了明显的变化.与对照相比,酶解前10min,可溶性氮含量无显著差异,而在酶解10～40min时,磷酸化酪蛋白酶解液中可溶性氮含量高于对照,同时磷酸化处理可以提高酪蛋白的水解度.

英文摘要：

Casein was phosphorylated with sodium tripolyphosphate （STP）, and then was hydrolyzed with trypsin. Through orthogonal experiments, we determined the optimal conditions were as follows： 5% of STP, 30 ℃ and pH 9. The highest phosphorylation degree （18.18 mg/g） was obtained after treatment for 3 hours. SDS-PAGE tests showed that obvious change was found in phosphorylated casein. In comparison to the control, the soluble nitrogen content in hydrolysates had no remarkable difference between phosphorylated casein and the control at the initial 10 minutes of hydrolysis; but the soluble nitrogen content of phosphorylated casein hydrolysates was higher than the control after hydrolysis for 10 minutes to 40 minutes. Moreover, phosphorylation treatment improved the degree of hydrolysis of casein.