title: Low molecular weight compounds responsible for savory taste of Indonesian soy sauce.
abstract: Indonesian soy sauce is made using only soybeans as the nitrogenous source. Moromi obtained from fermentation of yellow soybeans using Aspergillus sojae as the starter was investigated. The fraction with molecular weights of less than 500 Da obtained by stepwise ultrafiltration was then fractionated by several chromatographic procedures, including gel filtration chromatography and RP-HPLC. Several chemical analyses, CE profiles, and taste profiles were performed to obtain the most intense umami fraction. The main components eliciting or enhancing the umami taste present in the fraction were purified and identified by protein sequencing, ESI-MS, and (1)H NMR at 400 MHz. Besides free l-glutamic acid and aspartic acid, free aromatic amino acids such as l-phenylalanine and l-tyrosine may also play an important role in impressing savory or umami taste of Indonesian soy sauce at their subthreshold concentrations and in the presence of salt and free acidic amino acids. This is reported as a new phenomenon of the so-called bitter amino acids.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Nishihara-cho, Okinawa 903-0213, Japan.
authors.forename: Hanifah N
authors.initials: HN
authors.lastname: Lioe
authors.forename: Anton
authors.initials: A
authors.lastname: Apriyantono
authors.forename: Kensaku
authors.initials: K
authors.lastname: Takara
authors.forename: Koji
authors.initials: K
authors.lastname: Wada
authors.forename: Hideo
authors.initials: H
authors.lastname: Naoki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yasuda
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001230:Aspergillus / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D007214:Indonesia; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D045730:Soy Foods / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D013649:Taste
chemical_list: D000596:Amino Acids