Aroma deterioration during accelerated storage of sugar-free peach-flavored oolong tea: Key markers, degradation kinetics, and regulatory links between non-volatile and volatile components.

Aroma deterioration critically limits the flavor stability of sugar-free fruit-flavored tea beverages, yet its chemical drivers remain poorly understood. In this study, a ready-to-drink oolong tea was subjected to accelerated storage at four temperatures and analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), odor activity value (OAV), partial least squares discriminant analysis (PLS-DA), kinetic modeling, correlation analysis, and Gaussian calculations. Ten key aroma deterioration markers were screened. After 90 d at 25 °C, tea polyphenols, epigallocatechin gallate (EGCG), and epicatechin gallate (ECG) retained 68.7%, 59.3%, and 64.5% of their initial levels, respectively. The Logistic kinetic models showed good fits (Radj2 > 0.96) for all selected aroma markers, with cis-3-hexenyl acetate being the most temperature-sensitive marker. EGCG and ECG exhibited stronger independent associations with late-stage aroma modifiers than total polyphenols. Gaussian calculations further suggested EGCG forms thermodynamically favorable non-covalent interactions with representative aroma compounds. These findings provide marker-level evidence into flavor deterioration in sugar-free fruit-flavored teas.