分步酶解法制备黄浆水活性肽

黄浆水是传统豆制品点脑成型过程压榨出的废弃物，富含低聚糖、蛋白质等营养成分。该研究通过比较酶种类及用量、酶解温度、酶解时间对黄浆水蛋白质水解度的影响，采用正交试验优化获得黄浆水短肽最佳分步酶解工艺：（1）酸性蛋白酶加酶量2 000 U/g，pH 4.0，温度55 ℃，水解2 h；（2）中性蛋白酶8 000 U/g，pH 6.0，温度50 ℃，水解6 h。在此条件下进行验证，水解度可达25.95%，血管紧张素转化酶体外抑制活性达92.0%。采用酸性蛋白酶和中性蛋白酶分步酶解黄浆水制备短肽，制备条件温和，水解度高，可为豆制品加工废弃物的高值化利用奠定基础。

Preparation of oligopeptides from soybean whey by stepwise enzymatic hydrolysis

The soybean whey from tofu processing was the waste water, which contains protein and soy oligosacharides. In this study, the effect of enzyme variety, enzyme addition, hydrolysis temperature, time and pH on the hydrolysis degree of soybean whey protein were studied. The optimum stepwise enzymatic hydrolysis conditions for the preparation of oligopeptides from soybean whey were determined by orthogonal experiment: (1) acid protease addition 2 000 U/g, pH 4.0, 55 ℃ for 2 h. (2) Neutral protease addition 8 000 U/g, pH 6.0, 50 ℃ for 6 h. Under these conditions, the hydrolysis degree reached 25.95%, in vitro inhibitory activity of angiotensin converting enzyme was 92.0%. Using acid protease and neutral protease to prepare oligopeptide by stepwise enzymatic hydrolysis, the preparing condition was mild, and the hydrolysis degree was high, which could lay a foundation for comprehensive utilization of soybean product processing waste.