Salt taste perception in hydrocolloid systems is affected by sodium ion release and mechanosensory-gustatory cross-modal interactions

The perceived salt taste intensity of viscous solutions and gels of agar-agar and starches varying in their amylose/amylopectin ratio, as well as cellulose suspensions with fine, compact particles up to coarse, fibrous particles was systematically investigated. Saltiness intensity was correlated with instrumental-analytical data on viscosity, gel firmness, and sodium ion availability upon chewing. Salt taste perception was demonstrated to be dependent on the type and concentration of the polysaccharide. It was directly affected by viscosity, gel firmness, the mechanosensory perception of solid particles, and the rate of sodium release. On the one hand, sodium ion availability seemed to be a limiting factor determining salt taste perception in highly viscous and firm gel systems. On the other hand, texture-induced cross-modal interactions between taste and mechanosensory cues seem to play the key role impairing perceived taste impact at lower polysaccharide concentrations and, in particular, in the presence of solid particles. Intriguingly, solid particles that only minimally increased the viscosity drastically reduced perceived taste intensity, not only for saltiness, but also for sour, umami, and sweet tastes, with the exception of bitterness. These findings provide new knowledge on the impact of mechanosensation on taste perception.