红茶、绿茶和普洱熟茶体外抗氧化作用比较研究

Comparative Study of Antioxidant Effect on Black Tea,Green Tea and Pu'er Ripe Tea in Vitro

以3种不同类型茶叶——绿茶、红茶和普洱熟茶为材料,按照不同饮茶习惯,采用不同冲泡浓度茶汤进行体外抗氧化作用比较研究,并测定了3种茶样主要滋味品质成分含量及茶多酚(含黄酮类)冲泡溶出量。结果表明,绿茶水浸出物、多酚、游离氨基酸和可溶性总糖均高于红茶和普洱熟茶,3种茶叶体外抗氧化活性均随冲泡浓度增加而略有下降,在试验冲泡浓度范围内,绿茶有较强清除DPPH自由基的能力,红茶有较强的羟自由基清除能力,普洱熟茶清除超氧阴离子自由基能力较强;相关分析显示,O_2^-·清除率与多酚、黄酮溶出量显著负相关(p<0.01),而DPPH·和·OH清除率与茶多酚、黄酮溶出量无关(p>0.05),不同茶类多酚和黄酮类溶出量与O_2^-·清除率、DPPH·和·OH清除率呈负相关(p<0.05)。结果表明不同茶类体外抗氧化作用不同,一般饮茶浓度范围内,3种茶叶均具有较好的体外抗氧化作用,以饮用淡茶为宜,选择和饮用不同种类的茶叶可能带来更好的健康效应。

According Chinese habbit of drinking tea, compare the effect of antioxidant in vitro in tea of different concentrations with tea of different kinds of fermentation as the object of the research. And the main flavor components and TP（including flavonoids） are measured. The results show that water extract, TP, animo acids, and soluble sugar content of green tea are richer than black tea and Pu’er tea. The radical scavenging capacity of tea declines slightly（ p〉0.05） with rising concentrations of tea. It is found that green tea has the highest DPPH· radical scavenging capacity, black tea has the highest ·OH radical scavenging capacity and Pu’er tea has the highest O2-· radical scavenging capacity. Correlation analysis reveals that the TP（including flavonoids） content of tea has negative correlation with the radical scavenging capacity of tea and the radical scavenging capacity differs from different tea. The three types of tea present good radical scavenging capacity within the concentration of daily drinking. And weak tea is better.