Integrated non-targeted metabolomics, volatile profiling and targeted quantification characterize chemical changes in Jinhua jasmine tea during the scenting process

To clarify the chemical basis of quality changes during the scenting of Jinhua jasmine tea, samples from six processing stages were characterized using electronic sensory analyses and profiling of non-volatile and volatile compounds. Scenting altered the chemical and instrumental sensory profiles, with the base tea clearly separated from scented samples and further changes occurring across successive stages. Instrumental sweetness, richness and umami responses were generally higher after scenting. The summed contents of soluble sugars, amino acids and phenolic acids increased, whereas catechins, flavonols and flavones generally decreased, and these changes were associated with multiple instrumental taste responses. The summed content of volatile compounds progressively increased and was highest after Tihua. Odor activity value analysis highlighted 15 potential aroma contributors, including methyl benzoate, linalool and methyl anthranilate. Overall, successive scenting produced distinct stage-dependent changes in non-volatile and volatile composition, providing a chemical basis for quality changes in Jinhua jasmine tea.