重庆针形绿茶滋味特征及主要贡献物质

Taste characteristics and main contributing substances of needle-shaped green tea in Chongqing

滋味是评定茶叶品质的重要指标,为探索重庆针形绿茶滋味特征,该文通过检测分析绿茶主要呈味物质组分及含量,结合主成分及滋味物质贡献度进行分析。结果表明,重庆针形绿茶味感表现浓醇而鲜爽,总体品质较好。主要品质指标:水浸出物含量在45.2%~49.6%,多酚含量在14.7%~21.6%,游离氨基酸含量在2.8%~5.6%,咖啡碱含量在3.4%~4.7%(均为质量分数)。主成分分析表明,天冬氨酸、苏氨酸、丝氨酸、天冬酰胺、丙氨酸、蛋氨酸、异亮氨酸、亮氨酸、酪氨酸、组氨酸、赖氨酸、精氨酸12种氨基酸组分和没食子酸(gallic acid,GA)、表没食子儿茶素(epigallocatechin,EGC)、表儿茶素没食子酸酯(epicatechin gallate,ECG)3个组分为重庆针形绿茶滋味主要特征成分。而通过滋味物质贡献度[浓度/阈值(dose-over-threshold,Dot)]分析出天冬氨酸、谷氨酸、GA、表没食子酸儿茶素没食子酸酯(epigallocatechin gallate,EGCG)、ECG、EGC、儿茶素(catechin,D/L-C)对滋味的形成有重要贡献。滋味成分聚类分析表明永川、巴南两地的针形绿茶聚类效果较好。该研究为重庆针形绿茶品质成因及品质改善研究提供参考。

Taste is an important index for tea evaluation.To explore the taste characteristics of needle-shaped green tea in Chongqing,the main flavor components and contents of green tea were detected and analyzed in combination with the contribution of principal components and flavor substances.Results showed that Chongqing needle-shaped green tea had a heavy,mellow,and fresh taste,and the overall quality was good.Main quality indicators included that the content of water extract was 45.2%-49.6%,the content of polyphenols was 14.7%-21.6%,the content of free amino acids was 2.8%-5.6%,and the content of caffeine was 3.4%-4.7%.Principal component analysis showed that aspartic acid,threonine,serine,asparagine,alanine,methionine,isoleucine,leucine,tyrosine,histidine,lysine,arginine,gallic acid(GA),epigallocatechin(EGC),and epicatechin gallate(ECG)were the main characteristic components of Chongqing needle-shaped green tea.According to the analysis of taste substance contribution(Dot value),aspartic acid,glutamic acid,GA,epigallocatechin gallate(EGCG),ECG,EGC,and catechin(D/L-C)had important contributions to the formation of taste.Cluster analysis of taste components showed that the cluster effect of needle-shaped green tea in Yongchuan and Banan was better.This study provides a reference for the formation and improvement of the quality of Chongqing needle-shaped green tea.