Résumé
In human, food oral processing plays a role in our perception of taste, aroma and texture. This study aimed at investigating the role played by individual salivary flow rate and composition and oral mechanisms in the sensory perception of sweetened and thickened solutions. Thirty one subjects were selected with high differences in salivary flow rates and composition (protein concentration and amylase activity). They consumed twelve thickened solutions (varying independently in maltodextrin type (2), viscosity level (2) and sucrose level (3)) and rated the perceived thickness and sweetness intensities. After rating, boluses were collected in order to evaluate moistening by saliva. Residual oral coating was determined from oral rinsing water collected after bolus collection.Overall perceived thickness intensity increased with solution viscosity and sucrose concentration but did not depend on maltodextrin type; which was in line with rheological measurements of the solutions. Sweetness intensity was modified by sucrose concentration but also by changes in viscosity and maltodextrin. Bolus moistening by saliva varied between 43 and 89 % and the amount of solution coating the oral cavity varied between 0 to 3% (dry matter), depending on the solution. Regressions analyses were performed in order to evaluate the role of saliva and oral processing on sensory perception, while considering individual differences. Perceived thickness increased with oral coating, stimulated salivary flow rate and low amylase activity. This supposes an impact of temporal stimulation and oral enzymatic breakdown in texture perception. Perceived sweetness was similarly affected by these parameters but also increased with salivary flow rate at rest and bolus moistening, suggesting a higher clearance and thus a better dilution/ transport of sweet compounds to the taste buds. All together this study demonstrated that characterizing oral physiology and food oral processing can provide relevant information to explain inter-individual differences in sensory perception.