Characterizing flavor determinants and α-glucosidase inhibitory components in ancient tea plants and ‘Qiancha 1’ white teas

This study aimed to compare white teas derived from ancient tea plants (AT) and the cultivar '<i>Qiancha 1</i>' (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 (<i>p</i> < 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 (<i>r</i> = 0.83-0.93, <i>p <</i> 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.