Enzymatic preparation of peanut peptides and analysis of their antioxidant activity
In order to improve the utilization value of peanut meal and develop healthy and safe peanut pep-tide functional foods,peanut protein was extracted by alkaline extraction and acid precipitation,and peanut antioxidant peptides were prepared by alkaline protease enzyme,and the preparation process was optimized by one-way test,Plackett-Burman test,and response surface test,and the compositions and structures be-fore and after the enzyme digestion were determined,and their antioxidant stability was evaluated by simu-lating gastrointestinal tract digestion in vitro.The results showed that the optimal conditions for the prepara-tion of peanut antioxidant peptides were pH 9.5,at the temperature of 50 ℃,alkaline protease addition of 6 100 U/g,substrate concentration of 4%,and treatment for 4 h.The ABTS radical scavenging rate of the peanut antioxidant peptides prepared under these conditions was up to 90.31%±0.53%,and the degree of hydrolysis was up to 35.06%±1.29%,with no significant difference with the predicted values.The antiox-idant activity of peanut peptide prepared by this process was increased by about 50%compared with that of peanut protein;the peanut peptide still maintained high antioxidant activity after simulated digestion in vitro.The results provide a theoretical basis for the efficient preparation of peanut antioxidant peptides and the promotion of the application of peanut meal in food processing industry.