米糠蛋白抗氧化肽的制备及初步分离

Preparation and Preliminary Separation of Antioxidant Peptide of Rice Bran Protein

试验以米糠蛋白为原料,制备米糠蛋白抗氧化肽。以DPPH自由基清除率为指标,采用正交试验,优化碱性蛋白酶酶解米糠蛋白制备抗氧化肽的工艺条件;采用超滤、Sephades G-25柱层析分离纯化米糠蛋白抗氧化肽。试验结果表明,制备米糠蛋白抗氧化肽的最优工艺条件为:酶解温度45℃,pH 9.0,时间60 min,米糠蛋白底物浓度3%,碱性蛋白酶加酶量3 000 U.g-1。在米糠蛋白酶解产物中,Mr≤5 KDa组分的抗氧化活性最强,其对DPPH自由基清除率为68.7%。通过Sephadex G-25凝胶层析柱进一步分离得到4个混合组分,混合组分Ⅱ活性最强,其DPPH自由基清除率为75.83%。

Antioxidative peptides was produced using rice bran protein as raw material. Clearance rate of 1,1-diphenyl-2- picrylhydrazyl （DPPH） radical was taken as index,using orthogonal test to optimize technological conditions of alkaline protease technology for production of antioxidant peptides from rice bran protein which were separated and purificated by ultrafiltration and Sephades G-25column chromatography.The results showed that the optimal technological conditions were as following： enzymolysis temperature 45 ~C,pH 9.0,reaction time 60 rain ,protein substrate concentration 3%,addition level of alkaline protease 3 000 U＇g-l. The fraction of relative molecular weight ~〈5KDa,which was one of hydrolysis product of the rice bran protein,had the highest antioxidant activity and its clearance rate of DPPH reached to 68.7%. Four fix fractions were obtained from Sephadex G-25 column chromatography and the second fix fraction had the highest antioxidant activity,whose clearance rate of DPPH was 75.83%.