| RP-HPLC was employed to separate protease k hydrolysate(PKH) of rapeseed protein, and free radical scavenging activities of PKH and its fractions were evaluated by analyzing their scavenging activities on DPPH·,O-2·and·OH and the oxygen radical adsorption capacity (ORAC). The results showed that there was a significant positive correlation between DPPH·scavenging activity and hydrophobicity of rapeseed peptides, and the scavenging activity on DPPH· of glutathione(GSH) was equivalent to that of the strongest hydrophobic fraction with the IC50 value (0.183 8±0.002 1) mg/mL. The scavenging activities on O-2·and·OH of the rapeseed peptides increased after separation, while they were still weaker than those of GSH. The ORAC values of four fractions were higher than that of PKH, in which the ORAC values of two fractions were equal to that of GSH and one (F7) was 1.5 times as many ORAC values as GSH, with the ORAC value (Trolox) (2 413.41 ±162.98) μmol/mg. It was concluded that the RP-HPLC separation based on hydrophobicity significantly improved the free radical scavenging activities of rapeseed peptides, and the fractions (especially the F7) obtained could be used as antioxidants to develop the related functional food. |
