Process of the Preparation of Antioxidant Peptides by Enzymatic Hydrolysis of Yak Hide Protein

Antioxidant peptide were produced from the yak hide protein through alkaline protease hydrolysis. Based on a single-factor experiment and the Box-Behnken response surface design, the best antioxidant peptide were determined using the yak hide protein hydrolysis degree and the IC₅₀ of the yak hide protein hydrolysate scavenging activity against DPPH free radical as the evaluation indices. Results showed that, the best hydrolysis process was as follows: Temperature 51 ℃, enzyme dosage 10890 U/g, hydrolysis time 10.6 h, pH8.5, substrate concentration 5%. Per the above conditions, the degree of hydrolysis was 41.39%±0.69% and the IC₅₀ values of yak hide antioxidant peptides on DPPH·, ABTS⁺· and ·OH were 2.884, 2.110, 2.523 mg/mL, respectively. In conclusion, the antioxidant peptides of yak skin under the preparation process had good scavenging capacity for free radicals and strong reducing capacity, which indicated that the antioxidant peptides of yak skin would be expected to be developed and utilized as natural antioxidants.