基于主成分分析和聚类分析的湄潭翠芽游离氨基酸特性评价  

Evaluation of free amino acid characteristics of Meitan cuiya based on principal component analysis and cluster analysis

作　　者：彭琼瑶 刘玉倩[2] 敖芳 杨琦宏 杨家干 牛素贞 宋勤飞 PENG Qiongyao;LIU Yuqian;AO Fang;YANG Qihong;YANG Jiagan;NIU Suzhen;SONG Qinfei(College of Tea Science,Guizhou University,Guiyang 550025,China;Department of Modern Technical,Zunyi Vocational and Technical College,Zunyi 563000,China;Zunyi Ministry Bureau of Agriculture and Rural Affairs,Zunyi 563000,China)

机构地区：[1]贵州大学茶学院,贵州贵阳550025 [2]遵义职业技术学院现代农业系,贵州遵义563000 [3]遵义市种植业发展服务中心,贵州遵义563000

出　　处：《食品与发酵工业》2023年第6期283-291,共9页Food and Fermentation Industries

基　　金：贵州大学大学生创新创业训练计划项目(贵大(国)创字[2021]028);贵州省科技厅计划项目(黔科合成果[2019]4273号);贵州省林业厅计划项目(黔林科合[2019]09号)。

摘　　要：为明确湄潭翠芽游离氨基酸(free amino acid,FAA)的组成、含量及其营养、风味特性,以不同厂家的33份湄潭翠芽茶样为材料,采用氨基酸自动分析仪及高效液相色谱测定游离氨基酸种类和含量,通过滋味活性值(taste activity value,TAV)进行呈味特性评价、利用主成分分析和聚类分析进行综合评价。结果显示,湄潭翠芽游离氨基酸总量在36.933~59.201 mg/g,均值为45.923 mg/g。检测到的18种游离氨基酸含量在茶样间差异明显,变异水平达到中等以上。茶氨酸(theanine,Thea)、谷氨酸(glutamic acid,Glu)和天冬氨酸(aspartic acid,Asp)是湄潭翠芽中最主要的3种游离氨基酸。湄潭翠芽以非必需氨基酸(non-essential amino acid,NEAA)含量最高,其次为半必需氨基酸(儿童必需氨基酸,child essential amino acid,CEAA),必需氨基酸(essential amino acid,EAA)含量最低。湄潭翠芽中游离氨基酸的呈味特性表现为鲜味氨基酸>苦味氨基酸>甜味氨基酸,Thea是湄潭翠芽中最主要的呈味氨基酸,TAV值均值为315.61。Glu、Thea含量与滋味评分具有显著正相关关系。通过主成分分析提取到3个主成分,累积方差贡献率为80.428%,可代表湄潭翠芽中游离氨基酸的综合信息。游离氨基酸综合评分排名前3的茶样依次是CY16、CY19和CY12。聚类分析将湄潭翠芽分为三类,其游离氨基酸综合评分为第Ⅲ类>第Ⅱ类>第Ⅰ类,较好地反映了不同湄潭翠芽间游离氨基酸的差异。In this study,33 samples of Meitan cuiya from different manufacturers were used as materials to clarify the composition,content,nutrition,and flavor characteristics of the free amino acid(FAA)in Meitan cuiya.The types and contents of free amino acids were determined by an automatic amino acid analyzer(AAAA)and high-performance liquid chromatography(HPLC).Then the flavor characteristics were evaluated by taste activity value(TAV).Principal component analysis(PCA)and cluster analysis(CA)were used for comprehensive evaluation.Results showed that the total free amino acids in Meitan cuiya ranged from 36.933 mg/g to 59.201 mg/g,with an average of 45.923 mg/g.The contents of 18 kinds of free amino acids were significantly different among tea samples and the variation level was above medium.Theanine(Thea),glutamic acid(Glu),and aspartic acid(Asp)were the three main free amino acids in Meitan cuiya.The content of non-essential amino acid(NEAA)was the highest,followed by semi-essential amino acid(CEAA),and the content of essential amino acid(EAA)was the lowest.The flavor characteristics of free amino acids in Meitan cuiya were umami amino acids>bitter amino acids>sweet amino acids.Thea was the most important flavor amino acid in Meitan cuiya,with a TAV mean value of 315.61.The content of Glu and Thea had a significant positive correlation with taste scores.Three principal components were extracted by principal component analysis and the cumulative variance contribution rate was 80.428%,which could represent the comprehensive information of FAA in Meitan cuiya.The top three tea samples in the comprehensive score of free amino acids were CY16,CY19,and CY12.Meitan cuiya were divided into three categories by cluster analysis.The comprehensive score of free amino acids was class III>class II>class I and it better reflected the difference in free amino acids among different Meitan cuiya.

关 键 词：湄潭翠芽 游离氨基酸 滋味活性值 主成分分析 聚类分析 

分 类 号：TS272.5[农业科学—茶叶生产加工]