Confusing Tastes and Smells: How Odours can Influence the Perception of Sweet and Sour Tastes

TLDR

The study examined how the perceived odor of a scent influences the taste of a flavored solution. Experiment 1 measured sweetness, sourness, liking, and intensity for 20 odors and then assessed sucrose solutions flavored with those odors, while Experiment 2 replicated the design with citric acid and four selected odors. Certain odors enhanced sweetness, others suppressed it; the sweetness perceived in the odor best predicted taste ratings, and the most sweet‑smelling odor (caramel) suppressed citric acid sourness and enhanced sucrose sweetness, showing that odor effects extend beyond sweetness to sourness and align with prior flavor–taste associations.

Abstract

This study investigated the relationship between perception of an odour when smelled and the taste of a solution to which the odour is added as a flavorant. In Experiment 1 (E1) sweetness, sourness, liking and intensity ratings were obtained for 20 odours. Taste ratings were then obtained for sucrose solutions to which the odours had been added as flavorants. Certain odours were found to enhance tasted sweetness while others suppressed it. The degree to which an odour smelled sweet was the best predictor of the taste ratings. These findings were extended in Experiment 2 (E2), which included a second tastant, citric acid, and employed four odours from E1. The most sweet smelling odour, caramel, was found to suppress the sourness of citric acid and, as in E1, to enhance the sweetness of sucrose. Again, odours with low sweetness suppressed the sweetness of tasted sucrose. The study demonstrated that the effects of odours on taste perception are not limited to sweetness enhancement and apply to sour as well as sweet tastes. The overall pattern of results is consistent with an explanation of the taste properties of odours in terms of prior flavour–taste associations.