Shaking promotes the accumulation of flavor-imparting metabolites and enhances the sensory quality of spring black tea.

This study aimed to systematically investigate how shaking treatment influences the dynamic changes of nonvolatile and volatile metabolites during black tea processing and to determine its impact on the final tea quality. We compared conventional processing with shaking-incorporated methods using LC-MS, GC-MS, and HS-SPME-GC-MS. Shaking induced substantial metabolic alterations, identifying 3780 (LC-MS) and 129 (GC-MS) differential nonvolatile metabolites enriched in linoleic acid metabolism, amino acid metabolism, and caffeine metabolism. Key taste components, including theaflavins and kaempferol 3-sophorotrioside, accumulated significantly higher in finished shaking black tea (SBT), correlating with brighter infusion color and superior sensory scores. For volatiles, 272 differential metabolites were identified, with SBT exhibiting elevated esters, lactones, and aldehydes. These enhanced sweet, fruity, and floral aromas in SBT, driven primarily by γ-nonalactone (sweet) and hexyl benzoate (fruity). Our study demonstrates that shaking optimizes flavor-related metabolites, offering a theoretical foundation for optimizing black tea processing.