Exploring the effects of compressing and aging processes on functional components and flavor of white tea by omics methods

BACKGROUND: White tea (WT) is renowned for its distinct sensory attributes and functional properties. This study investigated how compression and aging influence the sensory and metabolic profiles of WT. Loose, compressed, aged loose and aged compressed (ACWT) teas were analyzed using sensory evaluation, metabolomics and chemometrics. RESULTS: As a result, compression enhanced floral and sweet aromas while reducing astringency and bitterness. Aging intensified fruity aromas and decreased astringency. The combination of compression and aging produced a complex fruity-woody aroma profile in ACWT, along with enhanced sweetness and minimal bitterness. The infusion of ACWT was darkened by the polymerization of theabrownins and thearubigins. While soluble solids increased in ACWT, free amino acids decreased, likely due to enzymatic hydrolysis and Maillard reactions. Decanal and cedrol were identified as associated with floral and fruity attributes of ACWT. KEGG analysis highlighted flavonoid biosynthesis (flavonols, flavones, anthocyanins) as essential. Correlation networks linked caffeine and polyphenols to bitterness, soluble sugars to sweetness, decanal and long-chain alkanes to fruity notes and β-cyclocitral and trans-2-dodecenal to grassiness. CONCLUSION: These findings demonstrate that compression and aging synergistically enhance the sensory quality of WT by modulating enzymatic and oxidative pathways. This process mitigates harsh flavors and enriches beneficial phytochemicals. The study provides practical insights for optimizing the production of premium aged, compressed WT, highlighting processing techniques as key drivers of flavor development and overall quality enhancement. © 2026 Society of Chemical Industry.