枸杞色素总抗氧化能力的研究

Study on the Total Antioxidant Activity of Gouqi(Lycium barbarum) Pigment

以甘肃静宁枸杞干果为主要原料,利用V(丙酮)∶V(石油醚)=1∶5为提取溶剂提取枸杞色素,测定了枸杞色素皂化前后的还原能力,清除DPPH·、O2-自由基、·OH能力,以及对油脂的抗氧化能力,并测定了与VC的协同作用,然后再与传统的抗氧化剂VE、VC进行比较,综合评定枸杞色素的抗氧化能力。结果表明:枸杞色素有一定的还原力,对DPPH·、O2-自由基、·OH有很好的清除作用,枸杞色素具有抗油脂氧化的能力,且抗油脂氧化能力随着色素浓度的增大逐渐增强;与几种抗氧化剂比较,抗氧化能力为VC>皂化前枸杞色素>VC+皂化前枸杞色素>VC+皂化后枸杞色素>VE>皂化后枸杞色素。

Dry fruits of Jingning Gouqi（Lycium barbarum）from Gansu province were used as the main material. The pigment was extracted by acetone and petroleum ether solvent with the volume ratio 1 to 5. The antioxidant activity was evaluated by the reducing power of the pigment of Gouqi before and after saponification, the scavenging capacity for free radical DPPH·, O2^- , ·OH, the antioxidant activity for lipid, the synergy with Vc were determined. Comparison with traditional antioxidants, such as VE and Vc on antioxidant activity was also tested. The results showed that the pigment of Gouqi had a certain degree of reducing power and could scavenge DPPH·,·OH and O2^- free radical effectively. Its inhibition of lipid oxidation was gradually increased with the concentration. The antioxidant activities in order was： Vc 〉 the pigment of Gouqi before saponification 〉 Vc ＋ pigment of Gouqi after saponification 〉 VE 〉 the pigment of Gouqi after saponification.