云南普洱茶不同溶剂提取物抗氧化活性研究

以芦丁与Vc为对照,测定云南普洱茶不同溶剂提取物清除DPPH自由基、羟自由基、超氧阴离子自由基、亚硝酸盐的能力及其还原力.结果表明:普洱茶不同溶剂提取物的抗氧化活性与其浓度成正相关,对DPPH自由基、羟自由基与超氧阴离子有较强的清除作用,对亚硝酸盐的清除作用不明显,具有一定的还原力.其中,乙醇沉析物、正丁醇提取物、乙醇提取物、乙醇溶解物对DPPH.自由基清除效果较好,相同浓度下优于芦丁;水提取物、乙醇沉析物及乙酸乙酯提取物对羟自由基清除效果较好,但效果不如Vc；乙酸乙酯提取物对超氧阴离子自由基和亚硝酸盐的清除作用较好,还原力也很强.

Antioxidant Activity of Different Solvent Extracts of Yunnan Pu-erh Tea

Antioxidant activity of different solvent extracts of Yunnan Pu-erh tea was studied in this paper. The scavenging ability of DPPH free radical, OH- free radical, superoxide anion free radical and nitrite of different solvent extracts of Pu-erh tea, as well as reducing power were investigated by using rutin and ascorbic acid(vitamin C)as the control. Results suggested that the different solvent extracts of Pu-erh had significant scavenging effects on the DPPH free radical, OH- free radical and superoxide anion free radical. All kinds of extracts had significant reducing power, but had no significant effects on nitrite. The antioxidant activity of different solvent extracts of Pu-erh had positive correlation with their concentrations. The scavenging effects of ethanol sedimentation segment, n-butanol extract, ethanol extract, ethanol soluted segment on the DPPH free radical were stronger than that of rutin control at the same concentration. In addition, the water extract, ethanol sedimentation segment and ethanol soluted segment had stronger ability of scavenging OH- free radical, but lower than that of Vc control. Acetal extract had stronger scavenging effects on superoxide anion free radical and nitrite and also had stronger reducing power.