Genetics of Sensory Thresholds: Taste for Phenyl Thio Carbamide

OCH2CH20H OC2H5which was found to be tasteless to both tasters and non-tasters.This compound, however, is extremely insoluble, notwithstanding the hydroxy ethoxy group present.Another example was noted containing a solu- blizing group and this was found to be bitter to both tasters and non- tasters.Some experiments by A. F. B.lakeslee have also indicated it is due to a difference in solubility.If this is the case, however, it remains just as inexplicable why these products should be insoluble in the saliva of some individuals and soluble in others.One possible explanation, offered with no experimental proof, is that the extremely small quantity necessary to produce taste is soluble in the saliva of all individuals, while the non-tasters have in their saliva a product, possibly a protein or colloid, which precipitates this as a very insoluble product and thus causes no taste to be sensed.One argument against this hypothesis is that non- tasters can place large quantities of these products on their tongues and not experience any taste.It would seem that the excess of reagent would precipitate all available protein and would then give a sense of taste, a sort of delayed taste.This, in fact, is experienced by some people, but whether this is due to the explanation offered is not known.Inasmuch as this phenomenon is somewhat similar in its manifestations to color blindness it has been designated taste blindness.It is admitted that there is not an exact scientific analogy but the term taste blindness so effectively describes this phenomenon its use is believed permitted.