A novel “tea nurturing flowers” perspective: tea dhool moisture‑controlled preservation of Osmanthus vitality for superior scented tea aroma

The ability of flowers to sustain fragrance release during the scenting process dominates the aroma quality of scented tea, rather than the capacity of tea dhool to passively adsorb volatiles. Plucked flowers remain metabolically active, whose physiological status governs the persistence and intensity of fragrance emission. Traditional practice has focused on maximizing aroma uptake by a low‑moisture tea dhool, inadvertently accelerating floral dehydration and metabolic collapse, thereby prematurely terminating peak fragrance release. This study introduces a novel "tea nurturing flowers" perspective, investigating how tea dhool moisture content modulates Osmanthus physiology and shapes the aroma quality of Osmanthus black tea (OBT). An optimized moisture level (25%) preserved cellular integrity, delayed water loss, and maintained stomatal opening, collectively sustaining floral volatile emission. By contrast, insufficient moisture (5-10%) caused plasmolysis and stomatal closure, while over‑hydration (45%) induced cell rupture and blockage of the porous tea dhool, impairing volatile transfer. Consequently, OBT produced at 25% moisture exhibited a more intense and persistent floral aroma, with elevated levels of key volatiles such as β‑ionone. Overall, this study repositions tea dhool from a merely passive adsorbent to a moisture‑mediated regulator of flower vitality, providing a mechanistic foundation and practical guidelines for improving scented tea quality.