Characterization of the key odorants of Fu Brick tea with different storage years using GC-O-MS combined with sensory evaluation

Fu brick tea (FBT) is prized for its unique aroma, yet the dynamic evolution of its key aroma-active compounds during storage remains unclear. To investigate this dynamic change, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and sensory omics analysis were employed for the comprehensive characterization of aroma-active compounds in five FBT samples. A total of 47 aroma-active compounds were detected, 15 of which were further determined as the key aroma-active compounds based on high flavor dilution (FD) factors, aroma intensities (AI), and odor activity value (OAV). Notably, although dihydroactindiolide exhibited high contents in HF15-HF19 (1733-2156 µg/kg), it was not classified as a key aroma compound. Multivariate statistical analysis revealed that the “stale” aroma attribute was strongly associated with aged FBT samples, while “minty” and “grassy” attributes were characteristic of newly produced FBT. Furthermore, aroma recombination and omission tests combined sensory evaluation confirmed that hexanal, 2-hexenal, ( E, E )-2,4-hexadienal, ( E, Z )-2,6-nonadienal, safranal, ( E, E )-2,4-nonadien-1-al, β -ionone, linalool and cedrol played decisive roles in constructing the overall aroma profile of FBT. This research provides detailed insights into the evolution of FBT aroma during storage, which can serve as a theoretical basis for optimizing FBT storage processes and improving its quality stability. • Aroma profile and key aroma-active compounds of different aged FBTs were analyzed. • 47 aroma-active compounds were determined using GC-O and GC-TOF/MS. • AI and AEDA further identified 27 key aroma-active compounds. • Aged FBT showed strong association with “stale” and new FBT with “mint” and “grassy”. • 9 key aroma-active compounds were confirmed common in different aged FBTs.