小麦胚芽蛋白活性肽的酶法制备及抗氧化活性的研究

Study on enzymatic preparation of wheat germ protein bioactive peptide and its antioxidant activity

研究了小麦胚芽蛋白活性肽的复合酶法制备及其抗氧化性的评价。通过试验研究了酶活性、酶的组合、酶解温度、时间等对小麦胚芽蛋白水解度及其抗氧化活性的影响,并对其酶解参数进行了优化。结果表明:第一步水解酶(中性蛋白酶)的最佳水解条件为底物浓度为4%,pH7.5,酶解温度40℃,加酶量10000 U/g,酶解时间3.0 h;第二步水解酶(木瓜蛋白酶)的最佳水解条件为酶活比1∶2、pH 7.5、温度55℃、时间1.0 h,此时小麦胚芽蛋白肽的DPPH·清除率和还原力最大,分别为64.78%和0.578。小麦胚芽蛋白酶解物经离心、脱色、脱盐、超滤处理,得到不同分子量范围的肽段,DPPH·清除率和还原力试验结果表明,抗氧化活性最强的活性肽的分子量小于3 k Da,其DPPH·清除率和还原力分别为67.82%和0.784。

The preparation of wheat germ protein bioactive peptide by complex enzymatic method and its antioxidant activity were studied.The effects of enzyme activity,enzyme combination,enzymic temperature and time on the degree of proteolysis and antioxidant activity of wheat germ proteinwere were studied,and the enzymic parameters were optimized.The results showed that the DPPH·clearance rate and reducing power of wheat germ protein bioactive peptide were 64.78%and 0.578,respectively.When the optimum hydrolysis conditions of the first step hydrolase(neutral protease)were:substrate concentration 4%,pH 7.5,temperature 40℃,enzyme dosage 10000 U/g,hydrolysis time 3.0 h,and the optimum hydrolysis conditions of the second step hydrolase(papain)were:the enzyme activity ratio of dispase to papain 1∶2,pH 7.5,temperature 55℃and hydrolysis time 1.0 h.The wheat protease hydrolysates were treated by centrifugation,decolorization,desalination and ultrafiltration to obtain peptides with different molecular weight range.The results of DPPH clearance and reducing power tests showed that the molecular weight of the active peptide with the strongest antioxidant activity was less than 3 kDa,and its DPPH clearance and reducing power were 67.82%and 0.784,respectively.