Texture-Taste Interactions: Exploring the Effect of Thickener Concentration on the Sensory Perception of Sweet, Sour, and Salty Tastes

The addition of thickeners to beverages remains the primary strategy for managing dysphagia. However, thickened beverages have poor compliance among patients, primarily due to a dislike of the taste and flavor. While thickeners produce a higher viscosity, which helps reduce the risk of aspiration, there is evidence that they also reduce taste sensations. Previous research suggests that rheological properties might explain the impact on taste perception; however, recent findings do not demonstrate this interaction. Therefore, this study aims to explore the impact of Nestle ThickenUp Clear on the taste intensity of sucrose (sweet), citric acid (sour), and NaCl (salty) when mixed at three concentrations compared to an unthickened control. The samples were analyzed for rheological properties (including viscosity and tan delta). A total of 56 untrained healthy participants completed the Temporal Check All That Apply (TCATA) and rated taste intensity and liking. This study presented significant findings on physical textural properties and sensory aspects; most importantly, Linear Mixed Models (LMM) revealed that saltiness (β = −4.16), sourness (β = −3.29), and sweetness (β = −3.43) all decreased significantly with the addition of thickener (p < 0.001), with the magnitude and slope varying considerably for each tastant. However, viscosity did not result in a decrease in taste intensity (as indicated by a lower marginal R² than conditional R²). These findings emphasize that unique interactions between tastants and thickeners drive taste perception, rather than being solely determined by physical rheological measures (such as viscosity and viscoelasticity). Future studies can extend these findings to other thickeners and more complex beverages, which will aid in identifying effective strategies to improve the taste and flavor profiles of thickened beverages.