Taste confusions following gymnemic acid rinse

The effect of a gymnemic acid (GA) rinse, which simulated a sweet-taste def icit, was measured on human taste perception and identification. Taste rati ngs showed that GA reduced the intensities of sucrose and aspartame to 14% of pre-rinse levels; over the recovery interval of 30 min, these values inc reased linearly to 63% of the pre-rinse levels. Repeated presentations of a set of 10 stimuli (five primarily or partly sweet-sucrose, aspartame, and NaCl-sucrose, acid-sucrose and quinine-sucrose mixtures; and five nonsweet- NaCl, KCI, Na glutamate (M5G), quinine HCl and citric add) for identificati on following water and GA rinses produced 'taste confusion matrices' (TCMs) . Correct identification of the sweet-tasting stimuli was reduced by 23% in presentations closely following the GA rinse, an effect that dissipated wi th time. Most misidentifications involved sucrose and mixtures containing s ucrose. In a second TCM experiment, GA was presented frequently within each session to maintain the sweet taste deficit, which revealed itself as spec ific confusions. Rinsing with GA impaired discriminability of sweet-nonswee t pairs of stimuli but enhanced discriminability of the aspartame-(NaCl-suc rose) pair. GA had no effect on discriminability of nonsweet stimulus pairs . The results suggest that specific error patterns in the TCM could be used to identify quality-specific taste disorders.