Comparison between Chemical Senses Thresholds for Capsaicin and Dihydrocapsaicin in Aqueous Solutions and Identification of the Area of Burning Sensation

Abstract

In the present study, the pungency detection thresholds for capsaicin and dihydrocapsaicin in aqueous solutions containing an emulsifier (polysorbate 80) were determined and compared. Thresholds were measured for 21 students (12 chili “users” and 9 “non users”) using a 3-Alternative Forced Choice sensory test with ascending concentrations of capsaicin and dihydrocapsaicin (0.025, 0.045, 0.090, 0.180 and 0.360 ppm, respectively). In addition, the panelists were asked where the irritation occurred (throat, tongue or both). The group Best Estimate Thresholds were 0.080 and 0.049 ppm for capsaicin and dihydrocapsaicin, respectively and differed significantly. Chili “users” and “non users” did not differ significantly in their perception of capsaicin and dihydrocapsaicin, suggesting that no desensitization effects occur. In accordance with previous studies, in most cases the first irritation was experienced in the throat.