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

Abstract

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 µg/L), (E)-linalool oxide (2863-6627 µg/L), and benzyl alcohol (4992-6859 µg/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.

Keywords: 3,4-Dimethoxytoluene (PubChem CID: 68126); Aroma recombination and omission; Benzaldehyde (PubChem CID: 240); Cedrol (PubChem CID: 65575); Citral (PubChem CID: 638011); Different aroma types; Fu brick tea; Key odor-active compounds; Methyl salicylate (PubChem CID: 4133); Nonanal (PubChem CID: 31289); dodecanal (PubChem CID: 8194); geraniol (PubChem CID: 637566); phenylethyl alcohol (PubChem CID: 6054); α-Ionone (PubChem CID: 5282108).