芝麻多肽的特性及其抗氧化活性对乳酸菌生长影响的研究

Characteristics of sesame polypeptide and effects of its antioxidant activity on growth of lactic acid bacteria

通过超声波辅助酶法制备芝麻多肽,在分析芝麻多肽的氨基酸组成、相对分子质量分布及抗氧化活性的基础上,研究芝麻多肽抗氧化活性对乳酸菌生长的影响。结果表明:芝麻多肽中谷氨酸、精氨酸、异亮氨酸和亮氨酸的含量较高;其相对分子质量分布主要集中在600～800之间;芝麻多肽羟自由基清除率、超氧阴离子自由基清除率和ABTS自由基清除率分别为74.65%、62.41%和66.8%;添加1.0 mg/m L的芝麻多肽能够明显促进乳酸菌的生长,提高乳酸菌的活菌数和乳酸的生成量;相关分析表明,乳酸菌活菌数与芝麻多肽超氧阴离子自由基清除率和ABTS自由基清除率的相关系数分别为0.88和0.81;乳酸含量与芝麻多肽羟自由基清除率、超氧阴离子自由基清除率、ABTS自由基清除率的相关系数分别为0.82、0.89和0.83。可见,芝麻多肽抗氧化活性对乳酸菌生长具有一定的影响。

Sesame polypeptide was prepared by ultrasound-assisted enzymatic method.By analyzing the amino acid composition,relative molecular weight distribution and antioxidant activity of sesame polypeptide,the effects of antioxidant activity of sesame polypeptide on the growth of lactic acid bacteria were studied.The results showed that the contents of glutamic acid,arginine,isoleucine and leucine in sesame polypeptide were higher.The relative molecular weight distribution was mainly between 600 and 800.The hydroxyl radical scavenging rate,superoxide anion scavenging rate and ABTS free radical scavenging rate of sesame polypeptide were 74.65%,62.41%and 66.8%,respectively.The addition of 1.0mg/mL sesame polypeptide could promote the growth of lactic acid bacteria,increase the viable counts of lactic acid bacteria and lactic acid production.Correlation analysis showed that the correlation coefficients between the viable counts of lactic acid bacteria and the superoxide anion scavenging rate,ABTS free radical scavenging rate of sesame polypeptide were0.88 and 0.81 respectively.The correlation coefficients between the lactic acid content and the hydroxyl radical scavenging rate,superoxide anion scavenging rate and ABTS free radical scavenging rate of sesame polypeptide were 0.82,0.89 and 0.83,respectively.Therefore,the antioxidant activity of sesame polypeptide had certain effect on the growth of lactic acid bacteria.