不同冲泡次数普洱生茶浸出物含量及滋味品质变化分析

采用超高效液相色谱-高分辨质谱联用技术结合茶叶感官审评方法,分析普洱生茶不同冲泡次数茶汤中浸出物的变化和滋味特征。从普洱生茶茶汤中共检出138 种浸出物,主要为氨基酸类、儿茶素及其衍生物、酚酸及其衍生物、黄酮类、生物碱类5 类物质,其对茶汤的主要滋味贡献为鲜味与苦涩味。普洱生茶茶汤的滋味总体评分与苦度、涩度、厚度呈显著正相关,不同冲泡次数下的浸出物总量与滋味总体评分呈显著正相关。浸出物总量及滋味品质均在第2泡时达到最大,后随冲泡次数的增加,浸出物总量不断减少,茶汤滋味逐渐淡薄。本研究围绕普洱生茶冲泡过程中浸出物的变化及其与滋味品质的关系进行分析,有助于揭示云南普洱生茶的耐泡性以及冲泡过程中茶汤滋味的变化特点。

Analysis of Variations in Contents of Extractable Components and Taste Quality of Pu-erh Raw Tea with Different Brewing Cycles

The contents of extractable components and taste characteristics of Pu-erh raw tea infusions obtained at different brewing times were analyzed by employing ultra performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) combined with sensory evaluatio in this study. The results showed that a total of 138 extractable components were identified, the predominant ones being amino acids, catechins and their derivatives, phenolic acids and their derivatives, flavonoids and alkaloids. These substances made a significant contribution to the umami, bitterness and astringency of tea influsions. The sensory score for taste of Pu-erh raw tea infusion was positively correlated with the degree of bitterness, astringency and thickness; there was also a positive correlation between the total amount of extractable components and the sensory score for taste for tea infusion obtained at each brewing cycle. The total amount of extractable components and the taste score reached their maximum values at the second brewing cycle, and then the total amount of extractable components decreased and the taste became increasingly plainer and thinner with increasing number of brewing cycles. These findings help to reveal the durability of Yunnan Pu-erh raw tea and the taste change of tea infusion during the brewing process.