核桃油微量组分对其氧化稳定性的影响

The influence of trace compositional on oxidative stability of walnut oil

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 to- copherols 〉 β- carotene 〉 flavonoids 〉 phenolics 〉 phospholipids; the order to inhibit second level oxidation was phenolics 〉 tocopherols 〉 flavonoids 〉 phospholipids 〉 β-carotene