Identification of volatile and odor-active compounds in Hunan black tea by SPME/GC-MS and multivariate analysis

Hunan black tea is well-known for its floral-honey aroma, but the volatile components responsible for the fragrance have not been elucidated yet. In this study, the volatile compounds in Hunan black tea were identified and quantified by the headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that 88 compounds were extracted and determined in Hunan black tea, including the dominant components Geraniol, phenethyl alcohol, phenylacetaldehyde, linalool, nonanal and other 5 aromatic compounds. Furthermore, the aroma-active compounds were identified by odor activity value (OAV). It was found that 24 aroma compounds, including geraniol with an OAV≥1 were regarded as the primary active aromatic compounds in Hunan black tea. Finally, partial least squares (PLS) regression analysis was employed and results revealed that Nonanal, trans-nerolidol, benzyl alcohol, and phenylethanol exhibit a positive correlation with the intensity of floral and sweet honey aromas. Overall, this study identified the volatile compounds responsible for the dominant floral-honey aroma in Hunan black tea.