反相高效液相色谱法分离菜籽蛋白水解物及其组分清除自由基能力的研究

摘要

采用反相高效液相色谱( RP-HPLC)技术分离菜籽蛋白的蛋白酶k水解物( PKH),并通过分析其DPPH·、O2-·、·OH的清除能力和氧自由基吸附能力( ORAC),评价了PKH及其分离组分清除自由基的能力。结果表明：菜籽肽清除DPPH·的能力与其疏水性之间具有显著的正相关性,疏水性最高的组分清除DPPH·的能力与谷胱甘肽(GSH)相当,IC50值为(0.1838±0.0021) mg/mL；分离后菜籽肽的O2-·和·OH清除能力虽然有所提高,但是仍然弱于GSH；4个分离组分的ORAC值高于PKH,其中2个组分的ORAC值与GSH的相当,1个组分( F7)的ORAC值是GSH的1.5倍,其ORAC值( Trolox )高达(2413.41±162.98)μmol/mg。研究认为,基于疏水性的RP-HPLC分离显著提高了菜籽肽清除自由基的能力,获得的分离组分(尤其是F7)可以作为抗氧剂开发相关功能性食品。%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 ac-tivities on DPPH·,O2-· and ·OH and the oxygen radical adsorption capacity ( ORAC) . The results showed that there was a significant positive correlation between DPPH·scavenging activity and hydropho-bicity 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 scav-enging activities on O2-·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 conclu-ded that the RP-HPLC separation based on hydrophobicity significantly improved the free radical scav-enging activities of rapeseed peptides, and the fractions ( especially the F7 ) obtained could be used as antioxidants to develop the related functional food.