β-伴大豆球蛋白的水解研究

Study on hydrolysis of β-Conglycinin

采用Nagano法从豆粕中分离β-伴大豆球蛋白并酶解制备水解肽,以单因素试验和正交试验确定酶解最佳条件,通过高效液相法分析β-伴大豆球蛋白水解肽的分子量分布,比较并检测了β-伴大豆球蛋白水解肽和大豆分离蛋白水解肽的体外抗氧化效果。结果显示:在20g/L的底物浓度下的最佳条件为酶和底物比10000U/g,温度55℃,pH7.5,水解时间4h,水解度为72.7%,明显高于酶解大豆分离蛋白51.4%的水解度,且水解时间更短。β-伴大豆球蛋白水解肽主要为130～1000u的短肽,占肽总量的86.3%,均一性极高。β-伴大豆球蛋白水解肽对O2-.和.OH均有清除作用,清除.OH的能力明显高于大豆分离蛋白水解肽,即β-伴大豆球蛋白的水解肽对大豆肽清除.OH的作用贡献更大。

According to Nagano method,β-conglycinin was isolated from soybean cake and was hydrolyzed to produce β-conglycinin hydrolysate peptide.Optimum enzymatic hydrolysis conditions were determined by single-factor and orthogonal test.Then the distribution of β-conglycinin hydrolysate peptide was detected by means of HPLC.Compared with soybean protein isolate hydrolysate peptide,the antioxidant effect of β-conglycinin hydrolysate peptide was analysized in vitro.Results showed that these optimum conditions were followed：10000 U/g of enzyme concentration,55 ℃,pH 7.5 and 4 h of reaction time when substrate concentration was 20 g/L,and the degree of hydrolysis（DH） was 72.7% in these conditions.In the same condition,the DH of soybean protein isolate was merely 51.4% in more reaction time.β-conglycinin hydrolysate peptides of 130~1000 u occupied 86.3% in total peptides.The antioxidant activity analysis showed that β-conglycinin hydrolysate peptide could eliminated both superoxide anion radical（O-2·） and hydroxyl radical（·OH）,and its ability eliminating ·OH was higher markedly than soybean protein isolate hydrolysate peptide.Therefore,compared with other soybean peptide,the β-conglycinin hydrolysate peptide had more efficience in eliminating ·OH