GC-MS结合电子鼻技术对不同茶区茉莉花茶香气的差异比较

Comparison of Jasmine Tea Aroma in Different Tea Regions by GC-MS and Electronic Nose

摘要:

为探究不同产区茉莉花茶香气差异，采用气相色谱-质谱（Gas Chromatography-Mass Spectrometry，GC-MS）结合电子鼻（Electronic Nose，E-nose）技术对西南、华南、江南三大茶区的8种茉莉花茶进行香气研究。结果表明，8个样品共鉴定出香气成分58种，其中西南、江南、华南茶区分别为45种、51种、47种。江南茶区香气化合物总量最高。共有香气成分主要包括邻氨基苯甲酸甲酯、顺式-3-己烯醇苯甲酸酯、乙酸苄酯、水杨酸甲酯、芳樟醇、吲哚等。其中水杨酸甲酯在江南茶区含量最高（22.32 μg/g），分别较华南、西南茶区高33.96%、68.01%；邻氨基苯甲酸甲酯（67.39 μg/g）和吲哚（43.84 μg/g）含量在华南茶区最高。茉莉花茶香气评价指数（Jasmine Tea Flavor Index，JTF index）分析表明西南茶区样品等级最高。香气聚类分析将共有香气成分分为3类，分别呈花香、茉莉花香和草木香。通过电子鼻技术可知样品香气物质变化与硫化物、碳氢化合物、芳香化合物有关，并能有效区别样品香气。综上，三大茶区样品香气种类差异不明显，但各香气成分含量差异显著（P<0.05），江南和华南茶区的样品特征性香气成分含量较高，西南茶区样品综合指数高。

Abstract:

To investigate the aroma differences among the jasmine teas from different production regions, gas chromatography-mass spectrometry (GC-MS) combined with the electronic nose (E-nose) technique was used to investigate the aromas of eight jasmine teas from three major tea regions, namely, the Southwest China, South China and Jiangnan. The results showed that a total of 58 aroma components were identified in the eight samples, with 45, 51 and 47 from the Southwest, Jiangnan and South China tea regions, respectively. The total number of aroma compounds was the highest in the tea from Jiangnan region. The common aroma components included mainly methyl o-aminobenzoate, cis-3-hexenyl benzoate, benzyl acetate, methyl salicylate, linalool, indole, etc. The content of methyl salicylate was the highest in the tea from Jiangnan region (22.32 μg/g), which was 33.96% and 68.01% higher than those from South and Southwest China tea regions, respectively; The contents of methyl o-aminobenzoate (67.39 μg/g) and indole (43.84 μg/g) were the highest in the tea from South China region. Analysis of the Jasmine Tea Flavor Index (JTF index) showed that the samples from the Southwest tea region had the highest grade. The aroma clustering analysis classified the common aroma components into three categories, which were floral, jasmine and herbaceous aromas respectively. By using the electronic nose technique, it was found that the variations among the aroma substances in the tea samples were related to sulfides, hydrocarbons and aromatic compounds. The electronic nose technique could effectively distinguish the teas’ aromas. In conclusion, the differences in the aroma types among the tea samples from the three tea regions were insignificant, but the contents of individual aroma components were significantly different (P<0.05). The tea samples from Jiangnan and South China tea regions had higher contents of characteristic aroma components, whilst the tea samples from the Southwest tea region had a high comprehensive index.