米曲霉发酵米糠制取米糠多肽及其抗氧化活性研究

Study on the preparation of peptides from rice bran and antioxidant activity by Aspergillus oryzae fermentation

摘要: 利用米曲霉对米糠进行发酵,研究了接种量、培养时间、培养温度和pH对发酵过程中蛋白酶活力和米糠多肽含量的影响,并利用响应面法对发酵条件进行了优化;分析了米糠多肽的分子量分布和抗氧化活性。结果表明,米曲霉发酵米糠的最佳条件为:接种量为14.6%,培养时间为48.6h,培养温度为29.5℃,pH为5.5,多肽含量达到128.4mg/g。发酵米糠多肽的分子量主要集中在500~800u之间,大约占75.6%,并且具有较强的抗氧化活性,对羟基自由基和DPPH自由基清除率最高分别达到86.2%和69.8%。

Abstract: The effects of inoculum concentration, incubation time, temperature and pH on protease production and peptide content were investigated by Aspergillus oryzae fermentation.The process conditions were optimized by using response surface experiments. The molecular weights and the antioxidant activity of the peptides were analyzed.The results showed that the optimal conditions for preparation of peptides were obtained as follows:inoculum concentration of 14.6%, incubation time 48.6h, temperature 29.5℃ and pH 5.5. The content of peptides reached 128.4mg /g.The peptide molecular weights ranged from 500 to 800 u which accounted for about 75.6% of fermentation peptides.The peptides in low molecular weight had antioxidant activity.The hydroxy free radical and DPPH radical scavenging rate were 86.2% and 69.8%, respectively.