关键词: 茶树, 香气成分, 绿茶, 气味活度值, 主成分分析

Abstract: The volatile aroma compounds of green teas made from the leaves of 6 high-quality tea strains in Hubei province were analyzed by sensory evaluation and headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) in this study. Our results showed that all tea samples had fresh, clean and high aromas, which were typical of green tea. Three of them, 01-4-7, 20-2-1 and 03-7-1, presented floral aroma. Meanwhile, a total of 55 aroma components were detected in the green teas with the major ones being alcohols, aldehydes and esters. Among the identified compounds, linalool, nonanal, (Z)-3-hexenyl hexanoate, geraniol and (E)-hex-3-enyl butyrate were predominant followed by dimethyl sulfide, methyl salicylate, heptanal and decanal. A significant difference was observed in the content of aroma compounds in the six green teas, and some of them had unique aroma components at high levels. Totally, nine aroma components with high odor activity value (OAV), including sequential linalool, decanal, dimethyl sulfide, β-ionone, geraniol, nonanal, heptanal, (E)-2-nonenal and (Z)-3-hexenyl hexanoate, were found in the present study, which may contribute to the aroma characteristics of the green teas. Multivariate analysis indicated that a marked difference was found in aroma components between six green teas and Fuding white tea, and four green teas including 03-7-4, 01-4-7, 07-7-68 and 03-7-1 showed a similarity in their aroma components. Among all these green teas, 20-2-1 had higher contents of esters and the highest total amount of aroma compounds while 07-7-64 was richer in aldehyde compounds. In addition, we also verified that there were significant differences in the contents of 19 aroma components in the measured samples.

Key words: Camellia sinensis, aroma components, green tea, odor activity value, principal component analysis