大球盖菇风味肽的制备及其抗氧化活性研究

Preparation of Flavor Peptides from Stropharia rugosoannulata and Study of Their Antioxidant Activity

摘要:

为促进大球盖菇（Stropharia rugosoannulata，S. rugosoannulata)深度开发利用，制备了大球盖菇风味活性肽基料，探究大球盖菇可溶性肽最佳酶解制备工艺，分析可溶性肽相对分子质量分布特征和酶解产物体外抗氧化活性。以可溶性肽质量分数为评价指标，结合仿生电子舌辅助筛选最佳蛋白酶、酶解方式、酶解温度、酶解时间、加酶量以及料液比；利用Design Expert软件设计三因素三水平试验，确定大球盖菇可溶性肽酶解最佳工艺。结果表明，中性蛋白酶和风味蛋白酶酶解效果较优，最佳酶解工艺为双酶分布酶解法。酶解温度50 ℃，料液比1 g∶30 mL；中性蛋白酶酶解时间76 min，加酶量1 175 U/g，酶解pH 7.5；风味蛋白酶酶解时间20 min，加酶量490 U/g，酶解pH 7.0。在此工艺条件下，酶解产物可溶性肽质量分数为245.45 mg/g，鲜味值及咸味值高，可有效改善不良风味；可溶性肽相对分子质量低且集中，其中相对分子质量小于500的占比达83.55%。1.0 mg/mL酶解产物DPPH自由基清除率和ABTS自由基清除率分别为81.84%和65.25%，IC₅₀分别为0.19 mg/mL和0.56 mg/mL，具有较好的体外抗氧化活性。综上，通过酶解工艺优化，大球盖菇风味活性肽基料可溶性肽产量高且相对分子质量低，呈味效果和抗氧化能力均较佳。

Abstract:

To promote the deeper utilization of Stropharia rugosoannulata (S. rugosoannulata) a flavorful and functional peptide base was prepared. The optimal enzymatic hydrolysis process for the soluble peptides from S. rugosoannulata was studied, and the molecular weight distribution characteristics and in vitro antioxidation activity of hydrolysate were analyzed. Based on the evaluation index of soluble peptide mass fraction, assisted by the results of bionic electronic tongue, the best protease, enzymatic hydrolysis mode, enzymatic hydrolysis temperature, enzymatic hydrolysis time, enzyme addition amount and material liquid ratio were screened, and then three factor and three level experiments were designed by using Design Expert software to determine the optimal enzymatic hydrolysis preparation process. The results showed that neutral protease and flavor protease had better hydrolysis effect. The optimum process for polypeptide preparation was as follows: the hydrolysis process was double enzyme step hydrolysis, temperature was 50 ℃, the ratio of material to liquid was 1 g∶30 mL, neutral protease hydrolysis time was 76 min, the amount of enzyme added was 1 175 U/g, the hydrolysis pH was 7.5, flavor protease hydrolysis time was 20 min, the addition amount was 490 U/g, and the hydrolysis pH was 7.0. With the optimal conditions, the soluble peptide mass fraction of the hydrolysate was 245.45 mg/g, and the umami and salty value were high, which can effectively improve the bad flavor. Meanwhile, the molecular weight of polypeptide was low and concentrated, and the proportion of polypeptide with molecular weight less than 500 is 83.55%. Moreover, enzymatic hydrolysate had good antioxidant activity in vitro. The scavenging rates of 1.0 mg/mL hydrolysate to DPPH and ABTS were 81.84% and 65.25%, respectively, and the IC₅₀ were 0.19 mg/mL and 0.56 mg/mL, respectively. To sum up, through optimization of enzymatic hydrolysis process, the hydrolysate of S. rugosoannulata had high polypeptide content, low molecular weight, demonstrated both good taste and antioxidant capacity.