酶解法制备条浒苔抗氧化肽工艺优化及其消化稳定性研究

本研究旨在优化中性蛋白酶水解条浒苔蛋白制备抗氧化肽的工艺条件,并对水解物的消化稳定性进行表征。以DPPH自由基清除率和水解度(DH)为指标,在单因素实验的基础上采用响应面分析法优化条浒苔抗氧化肽的制备工艺。通过三级膜分离系统将酶解物分离成不同相对分子质量的三个组分,采用体外模拟消化试验测试不同相对分子质量范围组分的消化稳定性。结果表明最佳酶解条件为:温度47℃、pH7.4、加酶量3300 U/g pro、时间3.3 h、固液比1:20 g/mL,在此条件下酶解物的DPPH清除率为84.33%±1.78%,模型预测值为85.53%,经检验,实测值与预测值无显著差异(P=0.444),模型可靠;相对分子质量小于10 kDa的两个组分具有较强的抗氧化活性和消化稳定性,大于10 kDa的组分抗氧化活性明显较低,经过消化酶消化后抗氧化性显著下降。条浒苔蛋白质经中性蛋白酶水解后可获得具有抗氧化活性和消化稳定性的蛋白肽,工艺模型可靠,水解物在食品中具有潜在应用价值。

Optimization of the Preparation of Antioxidant Peptides from Enteromorpha clathrata by Enzymolysis and Its Digestive Stability

The purpose of this study was to optimize the preparation condition of the antioxidant peptide from Enteromorpha clathrata protein by emzymatic method and to test its digestive stability. Using DPPH free radical scavenging rate and DH as indicators,the preparation conditions of antioxidant peptides were optimized by single factor experiment and response surface analysis methodology. The hydrolysate was separated into three components with different molecular weight by three-stage membrane filtration system. Digestive stability of the components were tested by simulated gastrointestinal digestion system in vitro.The results showed that the optimum enzymatic hydrolysis conditions were:Temperature 47℃,pH7.4,enzyme amount 3300 U/g pro,solid-liquid ratio 1:20 g/mL,and duration time 3.3 h. Under this condition,DPPH radical scavenging rate was 84.33%±1.78%,The predicted values of the model was 85.53%. T test showed that there was no significant difference between the actual and the predicted values,which indicated that the model was reliable.The two components with molecular weight less 10 kDa had strong antioxidant activity and resistance to gastrointestinal proteases in vitro. The antioxidant activity of the components with molecular weight over 10 kDa was significantly lower,and was significantly reduced after digestive enzyme digestion. In conclusion,peptides with antioxidant activity and digestive stability could be obtained from Enteromorpha clathrata protein by neutral protease hydrolysis. The process model was reliable,and the hydrolysate had potential application value in food.