Psychophysical responses to single and multiple presentations of the oral irritant zingerone: relationship to frequency of chili consumption.

There are few data on the psychophysical properties of zingerone, one of the pungent components in ginger, particularly in contrast to capsaicin. The time-intensity characteristics of zingerone irritation were examined using high-frequency, intermediate-frequency, and low-frequency users of chili, who rated the intensity of whole-mouth rinses of 1% zingerone at 6-s intervals for 3 min. Maximum intensity was reached within the first 20 s, while the zingerone was in the mouth. At this stage, there were no differences between groups. Following expectoration at 30 s, frequent users showed a more rapid decline in rated intensity than did intermediate users, who showed a more rapid decline than infrequent users. Capsaicin sensitization and desensitization are dependent upon the interstimulus intervals (ISIs) used. A second experiment, also using groups of high-, intermediate-, and low-frequency chili users, examined whether sensitization to zingerone could be demonstrated using ISIs based on the point of maximum intensity observed in the first study. In contrast to sensitization effects found with capsaicin, slight desensitization was observed over 10 successive zingerone stimuli. Following a 5-min hiatus in stimulation, further desensitization was observed over 10 results point to the ability of zingerone to self-desensitize, although the effect is of a smaller magnitude than that of capsaicin. None of these effects varied as a function of chili use. Analysis of the qualities that constituted zingerone irritation found that the sensations produced are predominantly burning and warmth, making it qualitatively similar to capsaicin.