Differentiation of four black tea cultivars based on E-tongue combined with HS-GC-IMS and UPLC-Q-TOF-MS/MS

This study systematically characterized flavor profiles and chemical basis of four distinct black tea cultivars using an integrated approach comprising electronic tongue-based taste profiling, UPLC-Q-TOF-MS/MS, and HS-GC-IMS. Marked variations in taste characteristics and aroma profiles were observed. A total of 76 volatile compounds were identified via HS-GC-IMS profiling, revealing unique chemical signatures: YH9 was characterized by abundant esters, DH by specific aldehydes and ketones, ZYH by alcohols, and QMH by compounds associated with its characteristic "Keemun aroma". UPLC-Q-TOF-MS/MS revealed significant differences in free amino acid profiles among the four cultivars. Electronic tongue analysis characterized these differential taste profiles, confirming that YH9 exhibited the highest intensities of bitterness, umami, and richness, while DH showed the strongest astringency. Lysine showed a particularly strong correlation with bitterness (r = 0.85). OPLS-DA identified 31 volatile compounds (VIP > 1) as potential markers for cultivar discrimination, providing a chemical basis for the observed flavor differentiation.

The online version contains supplementary material available at https://doi.org/10.1007/s10068-026-02250-5.