Relationship between salivary lubrication and temporal sensory profiles of wine mouthfeel and astringency sub-qualities

Wine mouthfeel plays an important role in sensory quality. Astringency, as an important aspect of mouthfeel, is composed of distinct sub-qualities associated with tannin-salivary colloidal interactions and loss of oral lubrication. Perception of wine mouthfeel is temporal – the sensory intensity of wine mouthfeel attributes changes over the oral process of evaluation. It remains unclear whether these changes in sensory are relevant to distinct physical processes. This study took sensory-instrumental and multivariate approaches to provide mechanistic insights into the wine mouthfeel during the temporal evaluation process. The sample set was created by doctoring ethanol, tannin, pH and mannoprotein in a Malbec. Wines were sensorily evaluated by a progressive profiling method and instrumentally tested using a soft-tribology protocol involving saliva. Results indicate that the scores of mouthfeel attributes are dependent on the interactive effect of matrix components. The decaying rate of the score for roughness after expectoration correlates with those for drying and pucker. The multivariate analyses indicate that tannin-protein interaction and high boundary friction in tribology are important in explaining the perception of all astringency sub-qualities. At the end of the evaluation, the boundary friction becomes less important in explaining the score of drying/roughness, while pH becomes less important in explaining the score of pucker. It is inferred that, after expectoration, saliva secretion recovers the oral lubrication; astringency sub-qualities are contributed less from the frictional mechanism but more from an alternative perceptive mechanism. The outcome could assist the wine industry in better managing the wine matrix to attain preferable mouthfeel characteristics.