Efficacy of two putative bitter blockers: bitter rankings from forced-choice paired-comparison tests (mean ± SEM) and summary of post hoc analyses1.

1All Friedman statistical tests of rank tests were significant at p≤0.0001. Abbreviations: SEM, standard error of the mean. Bitter compounds—0.5 M urea; 0.008 M caffeine; 1.19×10−4 M quinine; 5.60×10−4 M PROP (propylthiouracil); 4.92×10−7 M denatonium benzoate. Putative bitter blockers—NaG, 0.3 M sodium gluconate; MSG, 0.1 M glutamate. Diluent was distilled water. Blockers were compared separately against each bitter alone, bitter + blocker, and diluent. Rankings for bitterness range from 1 (least) to 4 (most); see Table S1 for ranking procedure. Different letters indicate rankings that are statistically different from each other within each row using p