title: Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor.
abstract: Three umami substances (glutamate, 5'-inosinate, and 5'-guanylate) were found by Japanese scientists, but umami has not been recognized in Europe and America for a long time. In the late 1900s, umami was internationally recognized as the fifth basic taste based on psychophysical, electrophysiological, and biochemical studies. Three umami receptors (T1R1 + T1R3, mGluR4, and mGluR1) were identified. There is a synergism between glutamate and the 5'-nucleotides. Among the above receptors, only T1R1 + T1R3 receptor exhibits the synergism. In rats, the response to a mixture of glutamate and 5'-inosinate is about 1.7 times larger than that to glutamate alone. In human, the response to the mixture is about 8 times larger than that to glutamate alone. Since glutamate and 5'-inosinate are contained in various foods, we taste umami induced by the synergism in daily eating. Hence umami taste induced by the synergism is a main umami taste in human.
authors.affiliation: Aomori University, Aomori 030-0943, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Kurihara
mesh_terms: D000818:Animals; D005421:Flavoring Agents / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D006157:Guanosine Monophosphate / Q000378:metabolism*; D006801:Humans; D007291:Inosine Monophosphate / Q000378:metabolism*; D007564:Japan; D008954:Models, Biological; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012624:Seaweed / Q000737:chemistry*; D013649:Taste / Q000502:physiology*; D013650:Taste Buds / Q000502:physiology
chemical_list: D005421:Flavoring Agents; D011956:Receptors, Cell Surface; D007291:Inosine Monophosphate; D018698:Glutamic Acid; D006157:Guanosine Monophosphate