Effect of Germination Time on Antioxidant Capacity of Brown Rice Glycoprotein

In order to clarify the effects of germination time on brown rice glycoprotein contents and its antioxidant properties,this study germinated brown rice for 12,24,36,48,60,72,84,96 h,respectively. The effects of germinated brown rice glycoprotein on DPPH radical,superoxide anion radical,hydroxyl radical scavenging ability,iron ion reduction ability and resistance to linoleic acid oxidation were investigated. Ascorbic acid was used as positive control. The relationship between germinating time and brown rice glycoprotein concentration or antioxidant ability were studied. Results showed that,the brown rice glycoprotein germinated for 84 h had the best antioxidant ability at the concentration of 4 mg/mL,and the scavenging ability of hydroxyl radical and superoxide anion radical was better than that of ascorbic acid,and the clearance rates were 99.49% and 99.39%,respectively. The scavenging ability of DPPH free radical,the ability of iron ion reduction and the ability of resisting linoleic acid were slightly weaker than those of ascorbic acid,the clearance rate was 88.11%,and the absorbance values were 2.06 and 0.211,respectively. The antioxidant capacity of brown rice glycoprotein was affected by germination time and concentration of sample. The germination time was significantly positively correlated with DPPH free radical,hydroxyl radical scavenging rate and anti-oil oxidizing ability(P<0.01),and iron ion. The reducing ability was significantly positively correlated(P<0.05). The glycoprotein concentration was also significantly positively correlated with the superoxide anion clearance rate,iron ion reduction ability and anti-asian oleic acid oxidation showed a very significant positive correlation(P<0.01).