Characterization of the key odor-active compounds in different aroma types of Fu brick tea using HS-SPME/GC-MSO combined with sensory-directed flavor analysis

Fu brick tea (FBT) is popular for its unique 'fungal flower' aroma, however, its key odor-active compounds are essentially unknown. In this study, the odor-active compounds of stale-fungal aroma (CJX), fresh-fungal aroma (QJX), and fermentation-fungal aroma (FJX) types FBT were extracted and examined by headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O). A total of 43 volatile and 38 odor-active compounds were identified by these methods. Among them, the content of dihydroactindiolide (4596-13189 mu g/L), (E)-linalool oxide (2863-6627 mu g/L), and benzyl alcohol (4992-6859 mu g/L) were highest. Aroma recombination experiments further verified that these odor-active compounds could be simulated the overall aroma profile of FBT successfully. Furthermore, omission experiments confirmed that 15, 20, and 15 key odor-active compounds in CJX, QJX, and FJX FBT, respectively. This study will provide a theoretical basis for comprehensively understanding the formation of characteristic aromas in FBT.

Automated summary

In this study, the key odor-active compounds of Fu brick tea were identified using headspace solid phase microextraction combined with gas chromatography-mass spectrometry and gas chromatography-olfactometry. A total of 43 volatile and 38 odor-active compounds were identified, with dihydroactindiolide, (E)-linalool oxide, and benzyl alcohol being the most abundant. Aroma recombination experiments verified that these compounds successfully simulated the overall aroma profile of Fu brick tea. This study provides a theoretical basis for understanding the formation of characteristic aromas in Fu brick tea.