Abstract: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.