测定核桃油对DPPH·、ABTS+·的清除能力,结合β-胡萝卜素脱色法,评价核桃油体外抗氧化能力。通过相关性分析、回归分析评价核桃油中共轭烯烃、羰基化合物、多酚、生育酚、黄酮、β-胡萝卜素及磷脂对核桃油氧化稳定性的影响。结果表明:核桃油具有一定的体外抗氧化活性,对DPPH·和ABTS+·的半抑制浓度(IC50)分别为0.161 g/m L和0.841 g/m L,通过β-胡萝卜素脱色法测得的核桃油抗氧化半抑制浓度(IC50)为1.292 g/m L,且核桃油体外抗氧化活性与其OSI显著相关(P<0.05)。同时发现,核桃油中7种微量组分含量与其OSI有显著相关性(P<0.05),其相关程度依次为:生育酚>总酚>黄酮>共轭烯烃>羰基化合物>β-胡萝卜素>磷脂,且抑制初级氧化的能力为:生育酚>β-胡萝卜素>黄酮>总酚>磷脂,而抑制次级氧化的能力:总酚>生育酚>黄酮>磷脂>β-胡萝卜素。

The antioxidant activity of walnut oil was assessed by 1,1-diphenyl-2-picrylhydrazyl( DPPH) radical scavenging capacity,2,2-azinobis( ABTS) radical scavenging capacity and β-carotene bleaching test. Results of these studies demonstrated that walnut oil possessed antioxidant activities and a significant correlation( P < 0. 05) was found between these three methods and Rancimat methods assays. The content of total tocopherols,total phenolics,flavonoids,carotene,phospholipids,conjugated diene value and total carbonyl compounds were measured,and a good correlation obtained between them and OSI( P < 0. 01). Also,the five antioxidant composition( tocopherols,phenolics,flavonoids,carotene and phospholipids) contribution to the production of hydroperoxides were 40. 22 %,1. 94 %,19. 14 %,37. 92 % and 0. 79 %,respectively. The order of antioxidation activity of first level was tocopherols > β- carotene > flavonoids > phenolics > phospholipids; the order to inhibit second level oxidation was phenolics > tocopherols > flavonoids > phospholipids > β- carotene