Preparation of antioxidant peptides from Zizyphi Spinosi Semen protein by enzymatic hydrolysis

Optimization enzymolysis technology for production of antioxidant peptides of Zizyphi Spinosi Semen protein were studied. The antioxidant activities of enzymatic hydrolysates from spine date seed protein were investigated by 1, 1- diphenyl- 2- picrylhydrazyl ( DPPH) radical scavenging activities. Effect of enzymolysis temperature, substrate concentration, ratio of enzyme to substrate ( E/S) , enzymolysis pH and hydrolysis time on the DPPH scavenging rate of enzymatic hydrolysate from spine date seed protein were taken by the single factor experiments. Technology parameters were optimized by Box- Behnken statistical design. The amino acid composition and content of enzymatic hydrolysate of Zizyphi Spinosi Semen protein was measured by protein sequencer.The results showed that when the extraction parameters were controlled at enzymolysis temperature 51.2℃, enzymolysis pH8.1, substrate concentration 4.7%, the DPPH scavenging rate could be up to 91.59%. The predictive models are feasible in practice.Enzymatic hydrolysate of Zizyphi Spinosi Semen protein, consisting of 17 kinds of amino acid, was rich in proline, glycine and glutamic acid.