Surface Texture of Taste Carriers Modulates Bitter Taste Identification

The aim of this study was to assess the relationship between texture and the correct identification of gustatory stimuli (sweet, salty, bitter, and sour) in both healthy participants and patients with taste disorders.

This cross-sectional study included 51 participants: 32 healthy individuals and 19 patients with taste disorders. Taste testing was conducted using filter paper strips with two different surface textures (smooth and rough). Three concentrations of each tastant (sweet, sour, salty, and bitter) were applied to the strips. Each strip was placed on the anterior part of the tongue, and participants were asked to identify the taste stimulus from a list of four options using a multiple forced-choice technique.

A significant difference between smooth and rough filter paper textures in the overall cohort of all participants was observed for the identification of bitter taste (mean identification scores: 2.25 ± 0.91 vs. 2.45 ± 0.96; mean difference: -0.22; 95% CI: -0.37 to -0.02; p = 0.035). No significant differences between smooth and rough textures were found for any tastant concentration in the overall cohort. Among participants with taste disorders, rough texture improved the correct identification of bitter taste at low concentration, but the effect did not reach statistical significance.

Our results provide preliminary evidence that surface texture may affect taste quality identification and should be further explored in future research. The rough texture can enhance the correct identification of bitter taste quality.