发酵菜粕中菜籽小肽分离纯化及其体外抗氧化活性研究

Studies on isolation, purification and antioxidant activity of rapeseed peptide from solid-state fermentation

研究芝麻粕固态发酵过程中产生的小肽的抗氧化活性。通过福林酚法测定发酵菜籽粕中的蛋白多肽含量为19.15%。从发酵菜籽粕中提取活性小肽,通过Sephadex G-15分离纯化,得到两个分子量不同的小肽,经测定分别是2肽和8肽。分别测定其清除二苯基苦基苯肼(DPPH)自由基活性、用水杨酸法测定其清除羟基自由基(·OH)活性、用铁离子还原法测定其的总还原能力。1 mg/ml的2肽、8肽的DPPH自由基清除率分别为83.47%、76.18%;1.2 mg/ml的2肽、8肽·OH清除率分别达到96.97%、69.27%;3 mg/ml的2肽和5 mg/ml的8肽的总还原力相当于0.5 mg/ml谷胱甘肽。结果提示,固态发酵菜籽粕中的小肽具有较强的还原力,对·OH和DPPH自由基均具有较强的清除作用,且抗氧化性随着小肽分子量的降低而增强。

The antioxidant activity of small peptide from rapeseed dregs solid-state fermentation will be researched. Small peptide content of fermented rapeseed meal determined by the forint phenol meth- od is 19.15%. The isolation of peptide was from aqueous extract of rapeseed meal fermented by micro- organism. Two components could be got when extracting solution of rapeseed peptide was separated by Sephadex G-15 gel chromatographic column. The peptides distributions were dipeptide and octopep- tide. Antioxidant activities of the rapeseed peptide were analyzed. The scavenging ability of DPPH and-OH were determined by the 2, 2＇- diphenyl-l-picrylhydrazyl assays and the salicylic acid meth- od respectively. The total reducing power was measured by ferric reduction ability. At 1 mg/ml, the DPPH scavenging activity of dipeptide and octopeptide was 83.47% and 76.18% respectively; At 1.2 mg/ml, the·OH scavenging activity of dipeptide and octopeptide were 96.97% and 69.27% respective- ly. The reducing powers of dipeptide at 3 mg/ml and octopeptide at 5 mg/ml were corresponded to glu- tathione whose concentration was 0.5 mg/ml. The results hinted that the rapeseed peptide has stronger reducing activity and the ability of scavenging DPPH and· OH. The antioxidant activity was enhanced with rapeseed peptide molecular weight reduced.