脱脂米糠蛋白酶解物的制备及抗氧化性

Preparation and Antioxidant Activity of Defatted Rice Bran Protein Hydrolysates

采用化学法提取脱脂米糠中的蛋白质,通过碱性蛋白酶水解脱脂米糠蛋白制得米糠蛋白酶解物并对其抗氧化活性、氨基酸组成与分子质量分布进行研究。结果表明:脱脂米糠蛋白酶解物的水解度达到22.16%,具有良好的抗氧化活性,对DPPH自由基、.OH具有很好的清除效果,能有效抑制亚油酸体系的自动氧化,且具有一定的还原能力和螯合金属离子能力。另外,酶解物中分子质量小于1000u的组分所占比例最高,达到77.85%。

Defatted rice bran protein was prepared by chemical method, and its hydrolysates （RBPHs） were obtained by enzymatic hydrolysis of defatted rice bran protein isolate using alcalase. The antioxidant activity, amino acid composition and molecular weight distribution profile of RBPHs were investigated. The results showed that the degree of hydrolysis （DH） of RBPHs was approximately 22.16% under the conditions employed in this study. RBPHs showed obvious scavenging activity against free radicals such as DPPH and hydroxyl radicals, and the antioxidant activity in a linoleic acid emulsion model system was good. Moreover, it exhibited an EC50 of 0.52 mg/mL in DPPH radical scavenging assay. The peptides with molecular weight lower than 1000 u represented the highest percentage （77.85%） in RBPHs.