Characterizing flavor determinants and α-glucosidase inhibitory components in ancient tea plants and 'Qiancha 1'...

This study aimed to compare white teas derived from ancient tea plants (AT) and the cultivar 'Qiancha 1' (QC1) using multi-omics approaches, focusing on differences in volatile/non-volatile components, sensory traits, and α-glucosidase inhibitory activity. Both teas shared sweet aromas and mellow tastes, but AT exhibited significantly stronger floral intensity (p < 0.05), whereas QC1 dominated in citrus/fruity aroma. GC-olfactometry and chemometric modeling identified six key metabolites, with trans-β-ionone (rOAV = 149.6) and β-damascenone (rOAV = 47.6) driving floral and citrus/fruity characteristics, respectively. Targeted metabolomics revealed significantly higher levels of ester-catechins, caffeine, and gallic acid in AT. These compounds exhibited significant dose-response correlations with bitterness, astringency, and α-glucosidase inhibitory activity (r = 0.83-0.93, p < 0.05), suggesting their dual role in flavor enhancement and hypoglycemic potential. This work provides scientific evidence and technical insights for the high-value utilization of ancient tea plants resources and the optimization of white tea processing technologies.