乌龙茶和绿茶品种茶鲜叶儿茶素类和嘌呤碱HPLC指纹图谱特征比较

HPLC Profiling of Catechins and Purine Alkaloids in Leaves of Oolong and Green Tea Cultivars

为揭示适制乌龙茶和绿茶品种鲜叶的基本生化特性,对集中种植的10个乌龙茶品种和10个绿茶品种春季和秋季鲜叶(一芽二、三叶)进行儿茶素类和嘌呤碱高效液相色谱(HPLC)指纹图谱构建,并采用主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA)等方法进行可视化模式识别。结果表明,乌龙茶品种与绿茶品种鲜叶样存在良好的类群区分。乌龙茶品种鲜叶样的儿茶素类和嘌呤碱指纹图谱的模式分布较为离散,且存在明显的季节性差异。乌龙茶品种相较绿茶品种鲜叶样拥有更丰富的儿茶素类和嘌呤碱组分。咖啡碱(CAF)、可可碱(TB)、表儿茶素没食子酸酯(ECG)、儿茶素(C)、表没食子儿茶素(EGC)和1种未知化合物为鉴别乌龙茶品种与绿茶品种鲜叶样的主要差异标志物,而7种未知化合物和表没食子儿茶素(EGC)则可视为鉴别乌龙茶品种春季鲜叶样与秋季鲜叶样的重要差异标志物。该研究结果可为适制乌龙茶和绿茶品种的选育与鉴定提供参考依据。

The contents of catechins and purine alkaloids in two or three leaves with a bud from the spring and autumn shoots of 10 oolong and 10 green tea cultivars(Camellia sinensis)were determined by high performance liquid chromatography.A visual pattern recognition was performed with the aid of the principal components analysis,orthogonal partial least squares discriminant analysis and other statistical methods.There were distinctive differences on the profiles between the two categories of cultivars.The catechin and purine alkaloid fingerprints of oolong teas appeared more abundant and diverse than those of green teas.They also differed significantly by the season the leaves were plucked.Among the chemical constituents,caffeine,theobromine,epicatechin gallate,catechin,epigallocatechin,and an unknown component were particularly prominent.They could be used as the major markers for differentiating the two teas.In addition,7 unknown components and epigallocatechin appeared suitable for distinguishing the spring shoots from the autumn shoots of oolong teas.