Comparing characteristic aroma components of bead-shaped green teas from different regions using headspace solid-phase microextraction and gas chromatography-mass spectrometry/olfactometry combined with chemometrics

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, beta-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.