Volatile metabolomics combined with rOAV and sensory evaluation reveals the aroma basis of black tea processed from the novel tea line ‘Jinlong No.1’ and its progenitor ‘Huangdan’

Fruity-floral black tea quality is co-determined by both cultivar and processing. Jinlong No. 1 (JL1), a newly released high-aroma cultivar, lacked identified quantitative aroma markers. To elucidate the aroma characteristics of the newly released high-aroma cultivar ‘Jinlong No.1’ (JL1), three black teas were analyzed through GC-MS/MS-based volatile metabolomics, sensory evaluation, and relative odor activity value analysis. These included JL1 fruity-floral black tea (JL1B), JL1 conventional black tea (JL1S), and ‘Huangdan’ fruity-floral black tea (HDB). JL1B achieved the highest overall aroma score (8.2 ± 0.8). Comparative analysis revealed 340 differential volatiles between the two fruity-floral teas, predominantly esters (18%) and ketones (16%). Key upregulated compounds in JL1B included hexyl butanoate and hexyl 2-methylbutanoate, while ( E )-2-nonenal and 1-nonen-3-ol were notably downregulated. Further comparison between the two JL1 teas identified 536 differential volatiles, with terpenoids (20%) and esters (18%) as the most abundant classes. Seventeen metabolites were commonly altered across comparisons, including the aforementioned esters. These findings establish specific quantitative targets for the precision processing and cultivar-directed breeding of premium fruity-floral black teas.