基于GC×GC-TOFMS-O分析3种武夷岩茶的关键香气成分

Analysis of Key Aroma Compounds in Three Varieties of Wuyi Rock Tea Based on GC×GC-TOFMS-O

摘要:

通过感官审评、全二维气相色谱-飞行时间质谱-嗅辨仪技术及香气活力值法，分析了三个茶树品种（肉桂、水仙、大红袍）毛茶在同一焙火温度下加工制成的三种武夷岩茶的关键香气成分。在香气品质上，肉桂以桂皮香为主，并带有花香；水仙以兰花香为主；大红袍花果香馥郁。3种武夷岩茶中共检测出337种挥发性成分，36种香气活性成分、26种关键香气成分。其中，在肉桂、水仙、大红袍中分别确定17、16、18种关键香气成分。结合热图分析，肉桂中确定香叶醇、3,5-二乙基-2-甲基-吡嗪、异戊酸正己酯、正己醛等8个主要关键香气成分；水仙中确定己酸戊酯、罗勒烯、甲基庚烯酮、吲哚、3-乙基-2,5-甲基吡嗪等10 个主要关键香气成分；大红袍中确定苯乙醇、苯甲酸甲酯、十一醛、2-甲基吡嗪、十二醛等8个主要关键香气成分，表明这些化合物对不同武夷岩茶香气品质的形成具有重要贡献。

Abstract:

The key aroma compounds of three varieties of Wuyi Rock Tea (RouGui, ShuiXian, and DaHongPao) processed at the same roasting temperature were determined and analyzed through sensory evaluation, comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry-olfactometry (GC×GC-TOFMS-O), and odor activity value (OAV). In terms of aroma quality, RouGui was dominated by a cinnamon aroma with an accompanying floral aroma, ShuiXian was dominated by an orchid aroma, and DaHongPao produced a floral and fruity aroma. A total of 337 volatile compounds were detected across three types of tea, including 36 aroma active compounds and 26 key aroma compounds. Specifically, RouGui, contained 17 identified compounds, ShuiXian contained 16, and DaHongPao contained 18. Heatmap analysis showed eight key aroma compounds in RouGui, including geraniol, 3,5-diethyl-2-methyl-pyrazine, hexyl isovalerate, and hexanal; ten key aroma compounds in ShuiXian, including amyl hexanoate, β-ocimene, 6-methyl-5-hepten-2-one, indole, and 3-ethyl-2,5-dimethyl-pyrazine; and eight key aroma compounds in DaHongPao, including phenylethyl alcohol, methyl benzoate, undecanal, 2-methylpyrazine, and dodecanal. These aroma compounds are therefore considered to make important contributions to the aroma quality of the different varieties of Wuyi Rock tea.