曲霉液态发酵制备藜麦肽及其抗氧化活性研究

Preparation of Chenopdium quinoa Wild peptide by Aspergillus liquid fermentation and study on its antioxidant activity

中文关键词:  藜麦  藜麦发酵  藜麦肽  曲霉发酵

英文关键词:Chenopdium quinoa Wild  Chenopdium quinoa Wild fermentation broth  Chenopdium quinoa Wild peptide  Aspergillus

中文摘要:

      目的 研究曲霉液态发酵条件对藜麦肽得率的影响, 通过单因素实验和正交实验优化藜麦肽发酵液制备工艺, 并对优化后的藜麦发酵液进行抗氧化活性研究。方法 以藜麦为原料, 经过糖化、液化后, 采用单因素实验考察黑曲霉和米曲霉的接种比例、接种量、发酵时间、料液比对藜麦发酵液中肽得率的影响, 通过正交实验以发酵液藜麦肽得率为指标, 对藜麦肽的发酵工艺进行优化, 并对优化后的藜麦发酵液进行1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基清除、羟自由基清除以及超氧阴离子清除能力的研究。结果 制备藜麦肽发酵液的最佳条件为黑曲霉与米曲霉接种比例为1:2、接种量8%、料液比7%、发酵时间48 h, 在此条件下藜麦发酵液中多肽得率为37.73%±0.70%, 其中藜麦肽发酵液对羟自由基清除率的半抑制浓度(half maximal inhibitory concentration, IC50)为89.02 μg/mL, 对DPPH自由基清除率的IC50为403.2 μg/mL, 对超氧阴离子自由基清除率的IC50为568.44 μg/mL, 其清除率分别为92.34%、87.56%、67.50%。结论 经过曲霉发酵有利于藜麦大分子的降解和小分子的转化, 可得到富含小肽并具有抗氧化功能的藜麦产品, 为以后藜麦发酵产品的开发提供数据参考。

英文摘要:

      Objective To study the effects of liquid fermentation conditions of Aspergillus on the yield of Chenopdium quinoa Wild peptides, to optimize the preparation process of Chenopdium quinoa Wild fermentation broth by one-way and orthogonal tests, and to investigate the antioxidant activity of the optimized Chenopdium quinoa Wild fermentation broth. Methods Chenopdium quinoa Wild was used as raw material, after saccharification and liquefaction, a single factor experiment was used to investigate the effects of inoculation ratio, inoculation amount, fermentation time and solid-liquid ratio of Aspergillus niger and Aspergillus oryzae on the polypeptide content in Chenopdium quinoa Wild fermentation broth. The orthogonal experiment was used with the polypeptide yield of Chenopdium quinoa Wild fermentation broth as an indicator to optimize the fermentation process of Chenopdium quinoa Wild peptide, the optimized Chenopdium quinoa Wild fermentation broth was also studied for 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging, hydroxyl radical scavenging, and superoxide anion scavenging capacity. Results The optimal conditions for preparing Chenopdium quinoa Wild peptide fermentation broth were an inoculation ratio of 1:2 between Aspergillus niger and Aspergillus oryzae, an inoculation amount of 8%, a feed to liquid ratio of 7%, and a fermentation time of 48 hours. Under these conditions, the peptide yield in Chenopdium quinoa Wild fermentation broth was 37.73%±0.70%, and the half maximal inhibitory concentration (IC50) of Chenopdium quinoa Wild peptide fermentation broth was 89.02 μg/mL for hydroxyl radical scavenging, 403.2 μg/mL for DPPH radical scavenging, and 568.44 μg/mL for superoxide anion radical scavenging, with scavenging rates of 92.34%, 87.56%, and 67.50%, respectively. Conclusion After Aspergillus fermentation is conducive to the degradation of Chenopdium quinoa Wild macromolecules and the transformation of small molecules, Chenopdium quinoa Wild products rich in small peptides and antioxidant function can be obtained, providing data reference for the development of Chenopdium quinoa Wild fermentation products in the future.