In this study, the aroma components of bead-shaped green teas were compared through headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry/olfactometry (GC–MS/O) coupled with chemometrics. A total of 62 volatile compounds were identified in 16 green tea samples. Notably, comparison of GC–MS/O and odour activity values (OAV) results revealed that nonanal, decanal, (E)-2-nonenal, β-ionone, and 1-octen-3-one were the most powerful aroma-active compounds that contributed to the aroma profile of the bead-shaped green teas. Furthermore, multivariate statistical techniques (such as principal component analysis, partial least squares-discriminant analysis, and hierarchical cluster analysis) were used to characterise the bead-shaped green teas according to their geographical origin and the flavour characteristics of their volatile compounds. Additionally, the variable importance in the projection method was used to identify 20 volatile markers that could successfully distinguish bead-shaped green teas on the basis of three flavour characteristics. The results of the analysis revealed that HS-SPME and GC–MS/O coupled with chemometrics can provide an effective method for characterising and classifying bead-shaped green teas.

中文翻译：

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顶空固相微萃取和气相色谱-质谱/比色法结合化学计量学比较不同地区珠状绿茶的香气成分特征

在这项研究中，通过顶空固相微萃取（HS-SPME）和气相色谱-质谱/嗅觉法（GC-MS / O）结合化学计量学比较了珠状绿茶的香气成分。在16个绿茶样品中总共鉴定出62种挥发性化合物。值得注意的是，GC-MS / O和气味活性值（OAV）结果的比较表明，壬醛，癸醛，（E）-2-壬烯，β-紫罗兰酮和1-辛烯-3-酮是最强的香气活性物质。有助于形成珠状绿茶香气的化合物。此外，多元统计技术（例如主成分分析，偏最小二乘判别分析，和层次聚类分析）根据其地理来源和挥发性化合物的风味特征来表征珠状绿茶。此外，在投影方法中，重要性的可变性被用来识别20种挥发性标记物，这些标记物可以根据三种风味特征成功地区分出珠状绿茶。分析结果表明，HS-SPME和GC-MS / O与化学计量学结合可以为表征和分类珠状绿茶提供有效的方法。