Exploration of tea-specific release kinetics and condensate recovery of odor-active compounds during boiling extraction of Liupao, Qingzhuan, and Tibetan teas.

Tea-specific control of aroma recovery is needed because volatile losses during extraction and concentration limit the sensory quality of instant tea. Thirteen consecutive 500-mL condensate fractions were collected during pilot-scale boiling-water extraction of Liupao (LP), Qingzhuan (QZ), and Tibetan (TB) teas and analyzed using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), odor activity values (OAVs), and nonlinear fitting curve analysis. Total volatile concentrations followed y = axb for all three teas (R2 = 0.98, 0.94, and 0.85 for LP, QZ, and TB, respectively), with QZ showing the fastest decline. 43, 60, and 38 volatile compounds were retained for LP, QZ, and TB, respectively. Using OAV > 1, 26, 40, and 26 odor-active compounds were identified. Cumulative recovery exceeded 70% after fractions 6, 7, and 9 for QZ, LP, and TB, corresponding to evaporation of 12%, 14%, and 18% of the initial water volume. This study provides certain guiding significance for the development of high-quality instant tea.