乳酸菌发酵核桃粕制备多肽及其体外抗氧化活性

Preparation of Polypeptide fromWalnut Meal Using Lactic Acid Bacteria Fermentation and Their Antioxidant Activity in vitro

以核桃粕为原料,乳酸菌作为发酵菌种,通过发酵制备核桃粕多肽并对其抗氧化活性进行研究。首先对发酵时间、发酵温度、接种量3个因素进行单因素试验,在单因素试验的基础上进行响应面优化,得到最佳发酵工艺条件,通过体外抗氧化试验测定多肽的抗氧化能力。结果表明:影响试验的因素大小顺序为接种量>发酵温度>发酵时间。核桃粕多肽产量制备的最佳工艺条件:发酵时间12 h,发酵温度37℃,接种量13%,在此条件下,多肽产量达到12.84 mg/g,与预测值差异不大,证明该优化工艺可靠,按照优化工艺制备所得核桃粕多肽在质量浓度为10 mg/mL时,DPPH自由基清除率可达82%,具有较强的还原能力。

Walnut active peptides were prepared using lactic acid bacteria fermentation with walnut meal as the raw material,and the antioxidant activity of the polypeptides was studied.First,a single factor experiment was carried out.Based on this experiment,three factors that had a greater impact on the polypeptides were selected for response surface analysis,and the results of the response surface experiment were analyzed using Design Expert 8.0.6 software.The optimal fermentation conditions were determined,and the antioxidant capacity of the hydrolyzed peptides was measured through in vitro antioxidant experiments.The results showed that the amount of inoculation,fermentation temperature,and fermentation time were the main factors affecting the fermentation process.The optimal technological conditions for the preparation of walnut meal polypeptides were:fermentation time 12 h,fermentation temperature 37℃,and inoculum amount 13%.Under these conditions,the peptide yield could reliably reach 12.84 mg/g.When the mass concentration of the peptide solution was 10 mg/mL,the scavenging rate of DPPH free radical was 82%,and it had a strong reducing ability.