title: Isolation and identification of the umami enhancing compounds in Japanese soy sauce.
abstract: To clarify the key compounds that account for the umami taste of soy sauce, a typical Japanese soy sauce, Koikuchi Shoyu, was separated by preparative chromatography, and the umami enhancing fractions were screened on the basis of an umami intensity of a 6.0 mM monosodium L-glutamate (MSG) solution. Liquid chromatography-time of flight mass spectrometry (LC-TOFMS), 1D/2D nuclear magnetic resonance spectroscopy (NMR) studies of the umami enhancing fractions led to the identification of N-(1-deoxy-D-fructos-1-yl)pyroglutamic acid (Fru-pGlu), N-(1-deoxy-D-fructos-1-yl)valine (Fru-Val), N-(1-deoxy-D-fructos-1-yl)methionine (Fru-Met), pyroglutamylglutamine (pGlu-Gln), and pyroglutamylglycine (pGlu-Gly). Although all the compounds identified were at sub-threshold concentrations in the soy sauce, a taste reconstitution experiment revealed that they contributed part of the umami taste of the soy sauce.
authors: Analytical Laboratory, Functional Ingredient Department, Ogawa & Co., Ltd., Urayasu, Chiba, Japan. kaneko.shu@ogawa.net
authors: Shu
authors: S
authors: Kaneko
authors: Kenji
authors: K
authors: Kumazawa
authors: Osamu
authors: O
authors: Nishimura
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D004151:Dipeptides / Q000737:chemistry / Q000302:isolation & purification; D005421:Flavoring Agents / Q000737:chemistry / Q000302:isolation & purification*; D005503:Food Additives / Q000302:isolation & purification; D018698:Glutamic Acid / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D012970:Sodium Glutamate / Q000302:isolation & purification; D045730:Soy Foods / Q000032:analysis*; D013649:Taste
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D005421:Flavoring Agents; D005503:Food Additives; C097425:pyroglutamylglycine; D018698:Glutamic Acid; D011761:Pyrrolidonecarboxylic Acid; D012970:Sodium Glutamate