不同海拔南川大树茶红茶挥发性物质特征分析  

Analysis of volatile compound characteristics in Camellia nanchuanica black tea at different altitudes

作　　者：杨娟[1,2] 陈善敏 王杰 张玉来 张莹 罗红玉[1,2] 袁林颖 YANG Juan;CHEN Shanmin;WANG Jie;ZHANG Yulai;ZHANG Ying;LUO Hongyu;YUAN Linying(Tea Research Institute,Chongqing Academy of Agricultural Sciences,Chongqing 402160,China;Chongqing Engineering Research Center for Tea,Chongqing 402160,China)

机构地区：[1]重庆市农业科学院茶叶研究所,重庆402160 [2]重庆市茶叶工程技术研究中心,重庆402160

出　　处：《食品与发酵工业》2024年第23期321-330,共10页Food and Fermentation Industries

基　　金：重庆市农业科学院市级财政科研项目(cqaas2023sjczqn015);重庆市自然科学基金面上项目(CSTB2022NSCQ-MSX1668)。

摘　　要：为探究不同海拔南川大树红茶挥发性物质特征,采用顶空固相微萃取联用气相色谱-质谱技术结合多元分析方法对其鲜叶及成茶挥发性代谢物进行分析。从鲜叶中检测出15类,574种物质,红茶中检测出16类,575种物质;不同海拔鲜叶中挥发性代谢物总量差异不显著。经萎凋、发酵、干燥等工序加工成红茶后,其香气较鲜叶明显丰富,其含量较高的物质类型是酯类、杂环类、萜类、醛类和醇类;而低海拔红茶(low attitude-congou black tea,LA-CB)挥发性物质含量达148.67μg/g,显著高于高海拔红茶(high attitude-congou black tea,HA-CB)(104.27μg/g)。经正交偏最小二乘法判别分析,分别从鲜叶组和红茶组中筛选出113种、179种差异代谢物,并对红茶组差异代谢进行风味注释,建立了差异代谢物风味轮,得出不同海拔茶园的南川大树红茶香气品质主要表现为果甜香,同时高含量的挥发性代谢物使低海拔红茶香气表现为更浓郁而持久,该结果与感官审评一致。而对代谢物相对气味活度值进一步分析发现,2-异丙基-3-甲氧基吡嗪、5-乙基-3-羟基-4-甲基-2(5H)-呋喃酮、苯甲硫醇、6-壬烯醛、二乙基二硫醚等物质可能是南川大树红茶独特香气品质的重要贡献物质,其中2-异丙基-3-甲氧基吡嗪具有坚果、豆、巧克力风味,推测是红茶成茶香气特征区别于其鲜叶的重要物质。该研究为不同海拔南川大树红茶特征品质区分及香气品质形成成因提供理论参考。To explore the characteristics of volatile compounds in Camellia nanchuanica black tea cultivated at various altitudes,a combination of headspace solid phase microextraction(HS-SPME)and GC/MS,along with multivariate analysis techniques,were employed to analyze the volatile metabolites in fresh leaves and the processed tea.The results revealed 574 substances out of 15 categories from the fresh leaves and a total of 575 substances of 16 categories in the congou black tea.And there was no significant difference in the total amount of volatile metabolites among fresh leaves picked at different altitudes.The aroma of processed black tea(processed by withering,fermentation,and drying)was significantly enriched compared to that of fresh leaves,with higher levels of esters,heterocycles,terpenes,aldehydes,and alcohols contributing to the flavor.Furthermore,the volatile substance of LA-CB(148.67μg/g)was significantly higher than that of HA-CB(104.27μg/g).Through orthogonal partial least squares discriminant analysis(OPLS-DA),113 and 179 differential metabolites were identified from the fresh leaf group and black tea group,respectively.A differential metabolite flavor wheel was established by annotating the flavors of the different metabolites of the black tea group,showing that fruity sweetness was the main aroma characteristic of C.nanchuanica black tea from tea gardens of different altitudes,while the high level of volatile metabolites in LA-CB prolonged its aromatic smell.This result was consistent with sensory evaluation.Further analysis of the relative odor activity values of the metabolites suggested that substances such as 2-isopropyl-3-methoxypyrazine,5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone,benzyl mercaptan,6-nonenal,and diethyl disulfide play a pivotal role in the formation of the unique aroma profile of C.nanchuanica black tea.Notably,2-isopropyl-3-methoxypyrazine,with its distinct flavors of nuts,beans,and chocolate,was hypothesized to be a key component that distinguished the aroma characteristics of the pr

关 键 词：南川大树茶 海拔 挥发性物质 特征 

分 类 号：TS272.52[农业科学—茶叶生产加工]