Considerations on the role of CaSR in the perception formation of kokumi flavor

Abstract

[Purpose] Gustatory receptors involved in the perception formation of kokumi flavor, fat flavor and umami flavor have been elucidated. In this presentation, the role of the CaSR (calcium-sensing receptor) in the perception of kokumi flavor was discussed.[Method] “Kokumi” is a common term having a broad and ambiguous meaning. It is not a suitable subject for academic study. For providing academically discussable term, I define kokumi flavor as "part of “kokumi” perception formed in involvement of CaSR".[Results] A schematic diagram showing the role of CaSR in the perception formation of kokumi flavor was created. In this diagram, kokumi flavor is assumed to be a perception formed in the brain when calcium taste information signal elicited by CaSR is integrated with olfactory information signal, basic taste information signal, and somatosensory information signal derived from food. This means that kokumi flavor is one of integration flavors. Next, while preparing the schematic diagram, I noticed that there should be a taste given by CaSR alone. This taste is named calcium taste. Calcium taste may be a basic taste rather than kokumi flavor. It is estimated that calcium taste is vague and evokes non-pleasant emotion while kokumi flavor is perceived as pleasant. The pleasantness of kokumi flavor can be evoked in the process of multimodal integration. Finally, glutathione, a representative kokumi-contributing substance, exhibits a mixed taste of sourness and calcium taste. There is no report on kokumi-contributing substances that activate only CaSR.