On the impact of the rheological and tribological properties of thickened drinks on perceived texture

Thickened beverages are commonly used to enhance swallowing safety in individuals with dysphagia, however, this modification can adversely affect palatability and reduce patient acceptance. This study examined the influence of drink formulation, specifically the choice of thickening agents, on texture perception by integrating sensory evaluation with a trained sensory panel along with rheological and tribological measurements using a tongue-mimicking surface. The friction coefficient at an in vivo –relevant sliding velocity of 3.5 mm s − 1 exhibited a strong correlation with perceived graininess. Furthermore, viscosity at a characteristic shear rate of 179 s − 1 was identified as a reliable predictor of perceived thickness. Sensory findings were interpreted within the International Dysphagia Diet Standardisation Initiative (IDDSI) framework. The results demonstrate that beverages classified within the same IDDSI consistency level can display significantly different rheological and tribological behaviors, and that such differences are perceptible to consumers. • The perceived graininess of beverages thickened with Maltodextrins, Starch and Xanthan gum correlates well with the friction coefficient measured using a biomimetic tongue-like surface at a characteristic sliding velocity of 3.5 mm s −1 . • The perceived thickness correlates well with the viscosity measured at a characteristic shear rate of 179 s −1 , but it could also be explained in terms of shear stress generated on the tongue surface. • Texture differences are perceived for thickened beverages within the same IDDSI consistency level. Unlike consistency, tribology and rheology can be used as predictor of the perceived graininess and thickness.