Preparation Comparison of Yak Blood Antioxidant Peptides and Its Purification

Abstract:

To research the best preparation of Yak blood antioxidant peptides，Yak blood was used to prepare three kinds of antioxidant peptides（abbreviated as BF，AB，BA） which obtained through fermentation with Bacillus subtilis，enzymatic hydrolysis with alkaline protease and combination of bacteria and enzyme respectively. Four kinds of antioxidant activities evaluation methods in vitro including scavenging of hydroxyl radical and superoxide anion，anti-lipid peroxidation，reducing power were presented to evaluate the antioxidant activities of Yak blood antioxidant peptides. Ultrafiltration and Gel chromatography were performed to purify the higher activity product. As results：the order of antioxidant activities of three antioxidant peptides was BA>BF>AP. BA had the most antioxidant activities of scavenging of superoxide anion，reducing power，anti-lipid peroxidation which indicated that the optimum preparation method was the combination of bacteria and enzyme.The antioxidant activity of antioxidant peptides with molecular weight <5 kDa which obtained through ultrafiltration was better compared to other molecular weights like >10 kDa and 5~10 kDa. Its IC50 of scaveng hydroxyl radical was 1.62 mg/mL. Then it was purified into four components by gel chromatography，in which component Ⅰwith the highest scavenging rate on hydroxyl radical. Its IC50 of scaveng hydroxyl radical was 0.52 mg/mL.