Ethanol and oral physiology modulate post-ingestion aroma persistence of carboxylic esters in wine-like systems

Aroma persistence, or after-smell, is a key sensory attribute of wine quality, yet the mechanisms governing aroma perception during the post-ingestion phase remain only partially understood. This study investigated how wine-like system (WLS) composition (ethanol content and pH) and individual oral physiological responses modulate the post-ingestion aroma persistence of carboxylic esters. Aroma perception was assessed using dynamic Time-Intensity sensory analysis, while salivary esterase activity and salivary pH were monitored over time during the post-ingestion phase following rinsing with WLSs differing in ethanol content and pH. Three carboxylic esters with different chemical structures were evaluated. Ethanol significantly increased both maximum perceived intensity and overall aroma persistence, with effects depending on ester chemical structure, being more pronounced for short- and medium-chain esters than for more hydrophobic compounds. Ethanol-containing systems induced a sustained reduction in salivary esterase activity throughout the post-ingestion phase, which may limit ester hydrolysis and contribute to prolonged aroma perception. Multivariate analysis further revealed that relationships between sensory persistence and oral physiological parameters depend on both ester structure and the temporal dynamics of salivary responses, with baseline and post-ingestion salivary conditions contributing differently to perceived intensity and persistence. Overall, these findings demonstrate that aroma persistence in wine-like systems arises from the interplay between matrix composition, odorant chemical properties, and dynamic oral physiological responses, providing new insights into the mechanisms driving post-ingestion aroma perception.