Abstract:
Gas chromatography-ion mobility spectrometry (GC-IMS) is a smart method that has been applied to determine the volatile compounds in Chinese teas, but its use in comparing the volatile compounds of different types of tea has not been mentioned. In this study, the volatile compounds found in four types of samples (green, yellow, white, and black teas) made with fresh leaves of Camellia sinensis (L.) Kuntze \'Zhongcha 111\' were analyzed using GC-IMS. The results showed that 93 volatile compounds were identified from our tea samples and that the average volume of aldehydes was higher than that for other compounds, especially in white tea. The different samples were successfully categorized using multivariate statistical analysis. Using partial least squares discriminant analysis (PLS-DA), we found 15 key compounds, including four differential components: (E)-2-hexenal, 2-furanmethanethio, 2-hexanol, and 1-octene. There were 29 common components, and their total content reached 386.0 μg/g. Moreover, the 3-methyl-2-butenal and dimethyl disulfide detected in the four samples were also differential compounds, varying according to the manufacturing technology. Thus, this study demonstrates that different types of teas can be discriminated easily using GC-IMS and that this is helpful to shorten the time for improving tea quality and developing new products.
摘要:
气相色谱-离子迁移谱(GC-IMS)是一种智能方法,已用于测定中国茶叶中的挥发性化合物,但是它在比较不同类型茶的挥发性化合物中的用途还没有被提及。在这项研究中,在四种类型的样品中发现的挥发性化合物(绿色,黄色,白色,和黑茶)用山茶的新鲜叶子制成(L.)Kuntze\“中茶111”使用GC-IMS进行了分析。结果表明,从我们的茶叶样品中鉴定出93种挥发性化合物,醛的平均体积高于其他化合物,尤其是白茶。使用多变量统计分析成功地对不同样品进行分类。采用偏最小二乘判别分析(PLS-DA),我们发现了15种关键化合物,包括四个差分组件:(E)-2-己烯,2-呋喃甲烷,2-己醇,和1-辛烯。有29个常见的组件,总含量达到386.0μg/g。此外,在四个样品中检测到的3-甲基-2-丁烯醛和二甲基二硫化物也是差异化合物,根据制造技术的不同而不同。因此,这项研究表明,使用GC-IMS可以轻松区分不同类型的茶,这有助于缩短改善茶质量和开发新产品的时间。