消化道酶连续水解制备苦荞球蛋白多肽及其抗氧化活性研究

Preparation of Tartary buckwheat globulin peptides by digestive protease hydrolysis sequentially and its antioxidant activity

采用胃蛋白酶、胰蛋白酶对苦荞球蛋白进行连续水解,以水解度(DH%)为指标,采用单因素分析底物浓度、酶底比、pH值、水解时间对苦荞球蛋白的酶解效果,并通过正交实验对胃-胰蛋白酶连续作用的酶解工艺进行优化;检测酶解产物的体外抗氧化活性。结果表明:苦荞球蛋白经胃蛋白酶酶解的最佳条件为:底物浓度30 g/L、酶底比为10%、pH值为2.0、反应时间为2.0 h;胰蛋白酶酶解的最佳条件为:底物浓度30 g/L、酶底比为5%、pH值为8、反应时间为2.5 h;胃-胰蛋白酶连续酶解最佳条件:经胃蛋白酶先水解1 h后再继续用胰蛋白酶水解1.5h,水解度为25.18%。和苦荞球蛋白相比,苦荞球蛋白酶解物的抗超氧阴离子能力及羟自由基清除能力均增强(p<0.05)。

Tartary buckwheat globulin was subjected to a two-stage in vitro digestion（pepsin followed pancreatin）. Taking degree of hydrolysis（DH%） as criterion, effects of substrate concentration, enzymesubstrate ratio, pH and enzymatic time on hydrolysis of Tartary buckwheat globulin were studied by single factor test, and the optimum conditions of pepsin-pancreatin sequential hydrolysis were determined by orthogonal experiment. The antioxidant potential of enzymatic hydrolysate intro was assessed. The result showed the optimal enzymatic hydrolysis conditions of tartary buckwheat by pepsin were： the substrate concentration was 30 g/L, the enzyme-substrate ratio was 10%, pH was 2, and the enzymatic time was 2 h. The optimal enzymatic hydrolysis conditions of pancreatin were： the substrate concentration was 30 g/L, the enzyme-substrate ratio was 5%, pH was 8, and the enzymatic time was 2.5 h. The optimal enzymatic hydrolysis of pepsin-pancreatin sequential hydrolysis were that： after hydrolyzed by pepsin 1 h and then hydrolyzed by pancreatin 1.5 h, the degree of hydrolysis was 25.18%. Compared with Tartary buckwheat globulin, the ability of zymolytes to remove hydroxyl radicals and to inhhibit the activity of superoxide radical were enhanced（p〈0.05）.