【摘要】 茶叶中品质成分复杂多样,与苦涩味相关的成分主要是咖啡碱和茶多酚。一般情况下,茶多酚指儿茶素类,实际上,茶多酚中的酚酸类物质对茶叶的品质也有较大的影响,其中最主要的是没食子酸。目前,茶叶中没食子酸、咖啡碱和儿茶素的检测一般采用高效液相色谱法,分析程序比较复杂,分析时间较长,一般为30~50 min。采用超高效液相色谱法同时对茶叶中的没食子酸、咖啡碱和6种儿茶素类进行分离测定,结果表明:没食子酸、咖啡碱和6种儿茶素类的分离度较好、过程简单,分析时间大大缩短,仅需6 min;茶叶中的表没食子儿茶素没食子酸酯含量最高,占儿茶素总量的40%~50%,是茶叶中儿茶素类中最主要的活性成分;茶叶中的没食子酸含量占茶叶的0.5%~1.5%,且随着采摘时间的延后没食子酸含量降低;咖啡碱含量均在3%~5%之间。方法线性较好,精密度和重复性的RSD均小于1%,方法的回收率在95%~107%之间。更多还原

【Abstract】 The quality components are complex and varied in tea, and caffeine and polyphenols are associated with astringent. In general, tea polyphenols refer to catechins. In fact, the phenolic acid in tea polyphenols also have great influence to quality of the tea, and one of the most important is gallic acid. At present, high performance liquid chromatography usually is used in the determination of gallic acid, caffeine and catechins in tea. But the analysis program is complex, the analysis time is long, and time generally is 30~50 min. The result is greatly influenced by tea matrix. Ultra performance liquid chromtography is used for the determination of gallic acid, caffeine and catechins in tea in this experiment. The analysis program is more simple, only for 6 min, and it greatly shortens the analysis time. The content of epigallocatechin gallate is the highest in tea, accounting for 40%~50% of the total catechin, and it is one of the most main active ingredients. Gallic acid in tea accounts for 0.5%~1.5%, and as the delay of picking time, the content is lower. The content of caffeine is between 3%~5%. The linear correlation is better, the RSDs of precision and repeatability are less than 1%, and the recovery of methods are between 95%~107%.更多还原