Cup aroma refers to the volatiles emitted from an empty cup after tea infusion. In this study, gas chromatography–olfactometry (GC–O) and the odor activity value (OAV) approach were employed to investigate the composition of fermented soybean-like cup aroma from raw Pu-erh tea. Further, the aroma recombination and omission tests were performed, and the results demonstrated that 2-methylbutyric acid, acetic acid, 4-methyl-3-penten-2-one, ethyl isobutyrate, nonanoic acid, and phenylacetic acid exhibited relatively high aroma intensities (AI) and OAVs among the 12 odor-active compounds that were detected in the fermented soybean-like cup aroma. The aroma recombination, which was performed employing the 12 odorants with AI ≥1 successfully mimicked the overall aroma profile of the fermented soybean-like cup aroma. The omission test revealed that 2-methylbutyric acid contributed significantly to the fermented soybean-like cup aroma. And the enantiomeric ratio (ER) of the ( S )- to ( R )-forms of 2-methylbutyric acid was 67:33.
The cup aroma (CA), a lingering scent in the empty cup after tea consumption, is important to sensory evaluation and overall experience; however, the compounds contributing to the distinct floral honey-like CA of Fenghuang Dancong oolong tea (FHDC) remain unknown. CA of FHDC had strong nectar, ginger-like, and floral, while the tea infusion (TA) was characterized by tropical fruit, sweet, and floral notes. OAV and GC-O analyses revealed that esters, aldehydes, and alcohols were major contributors to the CA, with distinct variations in the volatile compound profiles between TA and CA. Twenty-one and 17 aroma active compounds were identified in TA and CA, respectively. GC-O analysis of the CA revealed 17 key odorants, among which α-ionone, geraniol, 4-methylpent-3-en-2-one, ( E )-2-nonenal, heptanal, limonene, linalool, and ( Z )-2-penten-1-ol exhibited intensities of 3 or higher. An aroma recombination experiments confirmed the identification of 17 key odorants, successfully replicating the original floral honey-like cup aroma.
危险品化学品经营许可证（带存储）