相同加工原料下的6类茶体外抗氧化性能比较

Comparison of Antioxidative Activity in Vitro Among Six Kinds of Tea Made from the Same Raw Material

以春季茶树‘碧香早’的1芽2叶茶鲜叶为原料,选同一批次鲜叶采用蒸汽固样法将其制成固定样及加工成6类茶叶,并比较研究其体外抗氧化性能,以期为茶叶新产品开发及健康消费提供科学依据。结果表明,固定样及6类茶的还原能力和清除DPPH·、亚硝基、·OH及O2-·的能力均随茶汤浓度的增加而增强;固定样、绿茶、黄茶、黑茶、乌龙茶、白茶以及红茶对DPPH·的IC_(50)依次为0.017、0.019、0.019、0.020、0.021、0.022、0.038 mg(干茶浸出物)/mL,绿茶、固定样、乌龙茶、黑茶、白茶、黄茶和红茶对·OH的IC_(50)依次为1.438、1.695、2.988、4.163、4.606、4.881、6.847 mg(干茶浸出物)/mL,固定样、乌龙茶、黄茶、绿茶、白茶、黑茶和红茶对亚硝基的IC_(50)依次为1.285、1.401、1.514、1.525、1.847、2.146、5.163 mg(干茶浸出物)/mL。说明由相同原料加工而成的6类茶在浸泡相同质量干茶的条件下,因加工工艺不同而在体外抗氧化性能上存在差异,固定样及6类茶的抗氧化能力大小在总体上呈现不发酵茶(绿茶)>半发酵茶(乌龙茶)>全发酵茶(红茶)的趋势,其中以清除DPPH·的效果最好。

The antioxidative activities in vitro among six kinds of tea and fixed sample made from one bud andtwo leaves of‘Bixiangzao＇in spring were compared to provide scientific references for the developing of newtea products and healthy consumption. The results showed that the reducing power and the capacity ofremoving DPPH free radical, nitrate free radical, OH free radical and superoxide anion radical of all samplesincreased with infusion concentration increase. The IC50 of fixed sample, green tea, yellow tea, dark tea, oolongtea, white tea and black tea to DPPH was 0.017, 0.019, 0.019, 0.020, 0.021, 0.022 and 0.038 mg tea extract/mL,respectively. The IC50 of green tea, fixed sample, oolong tea, dark tea, white tea, yellow tea and black tea to·OH was 1.438, 1.695, 2.988, 4.163, 4.606, 4.881 and 6.847 mg tea extract/mL, respectively. The IC50 of fixedsample, oolong tea, yellow tea, green tea, white tea, dark tea and black tea to nitrate free radical was 1.285, 1.401, 1.514, 1.525, 1.847, 2.146 and 5.163 mg tea extract/mL, respectively. The results indicated thatantioxidative activity of six kinds of tea with the same dried tea quality made from the same raw material weredifferent from each other because of the processing. The whole antioxidative capacity had a trend ofunfermented tea（green tea） 〉semi-fermented tea（oolong tea） 〉completely fermented tea（black tea）, and theeffect of removing DPPH· was the best.