Low molecular weight compounds responsible for savory taste of Indonesian soy sauce.
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.
Lioe
Hanifah N
HN
Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Nishihara-cho, Okinawa 903-0213, Japan.
Apriyantono
Anton
A
Takara
Kensaku
K
Wada
Koji
K
Naoki
Hideo
H
Yasuda
Masaaki
M
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
D000596:Amino Acids