The role of TRPA1 and TRPV1 in the perception of astringency.

Astringency, commonly described as a drying, roughening, and/or puckering sensation associated with polyphenol-rich foods affects their palatability. While the compounds eliciting astringency are known, its mechanism of action is debated. This study investigated the role of transient receptor potential (TRP) channels A1 and V1 in astringency perception. If TRP A1 or V1 have a functional role in astringency perception, then desensitizing these receptors should decrease perceived astringency. Thirty-seven panelists underwent unilateral lingual desensitization of TRP A1 and V1 channels using mustard oil and capsaicin, respectively. Panelists then evaluated four astringent stimuli: epicatechin (EC), epigallocatechin gallate (EGCG), tannic acid (TA), and potassium alum (Alum), via 2-AFC and intensity ratings. When TRPA1 receptors were desensitized on one half of the tongue via mustard oil, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. Similarly, when TRPV1 receptors were desensitized on one half of the tongue via capsaicin, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. These findings challenge the notion that TRP channels play a pivotal role in astringency perception.