绿豆抗氧化肽的制备及理化特性分析

Preparation of Antioxidant Peptides from Mung Bean and Analysis of Its Physicochemical Properties

通过体外抗氧化活性、氨基酸组成及结构特征等指标对绿豆抗氧化肽最佳水解酶进行筛选,采用单因素与响应面实验优化制备工艺,并对制备的绿豆抗氧化肽进行理化特性分析。结果表明,中性蛋白酶制备的绿豆肽抗氧化活性最强,疏水性和芳香族氨基酸的含量较高,分别为261.85、73.42 mg/g,且具有较强的表面疏水性;从结构分析中可看出其具有较强的疏水性结构,中性蛋白酶水解后微观结构由紧密的球状分布变为多孔的碎片状分布,粒径变小,证实绿豆肽的抗氧化性与氨基酸组成及疏水结构密切相关。优化后的最佳酶解工艺为底物浓度30 mg/mL,加酶量2.24%,酶解时间3 h,酶解温度50℃,溶液pH 6.97,此条件下制备的绿豆抗氧化肽以小于1000 u的肽段为主,占比为87.65%,水解度为18.70%,DPPH·清除率为(85.61±0.37)%,且发现其浓度与抗氧化活性呈正相关的量效关系。

In this research,the optimal hydrolase of antioxidant peptides from mung bean was screened by in vitro antioxidant activity,amino acid composition and structure characteristics,the preparation process was optimized by single factor and response surface methodology,and the physicochemical properties of the antioxidant peptides from the prepared mung bean were analyzed.The results showed that the mung bean peptide prepared by neutral protease had the strongest antioxidant activity,and the content of hydrophobic and aromatic amino acids was high,that is,261.85 mg/g and 73.42 mg/g,respectively,and it had strong surface hydrophobicity.It could be seen from the structural analysis that the mung bean peptide had a strong hydrophobic structure.After hydrolysis with neutral protease,the microstructure changed from a tight spherical distribution to a porous fragment-like distribution,and the particle size became smaller,confirming that the antioxidant activity of mung bean peptide was closely related to amino acid composition and hydrophobic structure.The optimal enzymolysis process after optimization was as follows:substrate concentration of 30 mg/mL,enzyme dosage of 2.24%,enzymolysis time of 3 h,enzymolysis temperature of 50℃,and solution pH of 6.97.The mung bean antioxidant peptides prepared under these conditions were mainly composed of peptide segments less than 1000 u,accounting for 87.65%,the degree of hydrolysis was 18.70%,and the DPPH free radical scavenging rate was(85.61±0.37)%.And it was found that the concentration of antioxidant peptides from mung bean had a dose-effect antioxidant activity.