Sweetness of sucrose, neohesperidin dihydrochalcone, and saccharin is related to genetic ability to taste the bitter substance 6-n-propylthiouracil

Abstract

‘Tasters’ and ‘nontasters’ of the bitter compound, 6- n -propylthiouracil, were asked to judge the taste intensity of various compounds and the loudness of a 1000 Hz tone. Differences between tasters and nontasters in their suprathreshold magnitude estimates of sweet-tasting compounds, in particular, were examined with two different stimulation methods (front, dorsal-surface flow and whole mouth ‘sip and spit’) and with two different procedures for putting data onto a common intensity scale. With the first procedure, data were normalized to the strongest salt used (1.0 M NaCl) under the assumption that salt is equally intense to tasters and nontasters. Since differences in perceived taste intensity between these two groups were under investigation, the second normalization procedure used the assumption that tasters and nontasters have similar perceptions of loudness. This application of a new cross-modal matching technique suggests that the perceived sweetness of sucrose, neohesperidin dihydrochalcone, and saccharin is more intense to tasters than to nontasters.