PTC PROP TASTING - ANATOMY, PSYCHOPHYSICS, AND SEX EFFECTS/

Taste worlds of humans vary because of taste blindness to phenylthioca rbamide (PTC) and its chemical relative, 6-n-propylthiouracil (PROP). We review early PTC studies and apply modern statistical analyses to s how that a higher frequency of women tasted PTC crystals, and were tas ters (threshold classification). In our laboratory, scaling of PROP bi tterness led to the identification of a subset of tasters (supertaster s) who rate PROP as intensely bitter Supertasters also perceive strong er tastes from a variety of bitter and sweet substances, and perceive more burn from oral irritants (alcohol and capsaicin). The density of taste receptors on the anterior tongue (fungiform papillae, taste buds ) correlate significantly with perceived bitterness of PROP and suppor t the supertaster concept. Psychophysical data from studies in our lab oratory also show a sex effect; women are supertasters more frequently . The anatomical data also support the sex difference; women have more fungiform papillae and more taste buds. Future investigations of PTC/ PROP tasting and food behaviors should include scaling identify supert asters and separate sex effects.