Abstract:

The antioxidant pepetides was prepared by hydrolysis of enzymolysis of buckwheat globuli by the alkaline protease, the papaya protease and the pancreatin. The operation condition for hydrolysis was optimized by analyzing the degree of hydrolysis and scavenging activity of O2·. The hydrolyzate was separated by Sephadex G-25 gel filtration Chromatography and further subjected to the antioxidant activity assay the study of molecular weight distribution. The result showed that the alkaline protease hydrolyzing presented higher hydrolysis efficiency than the papaya protease and the pancreatin and the optimum conditions were as follows: enzyme concentration of 20000 U/g, 55 ℃, pH 9.0, substrate concentration 5% and 2 h of reaction time. The fraction with molecular weight less than 1000 D displayed higher antioxidant activity and the IC50 values for O2·、·OH and DPPH·were 0.75, 0.897 mg/ml and 0.38 mg/ml.

Key words: buckwheat, globulin, enzymatic hydrolysis, biological active peptides, antioxidant