Sourness is a primary taste quality that evokes an innate rejection response in humans and
many other animals. Acidic stimuli are the unique sources of sour taste so a rejection
response may serve to discourage ingestion of foods spoiled by acid producing
microorganisms. The investigation of mechanisms by which acids excite taste receptor cells
(TRCs) is complicated by wide species variability and within a species, apparently different
mechanisms for strong and weak acids. The problem is further complicated by the fact that …