僵蚕抗氧化多肽的初步分离

s a natural antioxidant, antioxidant peptides are used in functional food, cosmetics and pharmaceutical industry. Production of antioxidant peptide from natural products becomes an active domain of research. There are a great deal of sericultural resources in China. The white muscardin silkworms, Bombyx batryticatus, are rich in proteins with high quality and a variety of biological activity. In our current study, the antioxidant peptide was produced from enzymatic hydrolysate of white muscardin silkworm and was preliminary separated through the ultrafiltration, The antioxidant activity was analyzed for the practical application of feasibility. The main results were as follows: DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity was used as the criterion for antioxidant activity. Five proteases, alcalase, neutral protease, papain, trypsin and pepsin, were employed. Peptides derived from trypsin hydrolysate exhibited the highest DPPH radical scavenging activity. Protein was enzymatically hydrolyzed at 50 ℃, pH 6.9, enzyme concentration 0.31 g/L, substrate concentration 3 g/L, enzymatic hydrolysis time 3.67 h as hydrolysis conditions. 0.4996 g/L of antioxidant peptide was obtained, whose DPPH clearance was 60.1%. After ultrafiltration to obtain the low-molecular weight peptide less than 3 kDa, the DPPH scavenging activity arrived at 95.8%. The concentration for DPPH scavenging activity of 50% was 1.5 g/L, the total reductive activity and lipidsome oxidation inhibition was quite equal with ascorbic acid. High temperature treatment (boiling water bath) for 2.5 hours as well as repeated freeze-thaw for 5 times, seemed not to affect the antioxidant activity. But the antioxidant activity decreased with the increasing storage days at room temperature. This study provided preliminary theoretical basis on producing antioxidant peptide with white muscardin silkworm.