Simultaneous quantification of twenty Amadori products in soy sauce using liquid chromatography-tandem mass spectrometry.
A liquid chromatography-tandem mass spectrometry method using a pentafluorophenylpropyl-bonded silica column was developed to simultaneously quantify twenty Amadori products (APs), including N-(1-Deoxy-d-fructosyl-1-yl)-l-isoleucine (Fru-Ile) and N-(1-Deoxy-d-fructosyl-1-yl)-l-leucine (Fru-Leu), in soy sauce, without the need for an ion-pairing reagent or sample derivatization. The method was applied to six types of soy sauce, to determine the total AP levels and the levels of individual APs. The level of total APs widely varied between the eight samples, from 358mg/L to 24347mg/L. The concentrations of N-ε-(1-deoxy-d-fructosyl-1-yl)-l-lysine (Fru-Lys) and N-(1-deoxy-d-fructosyl-1-yl)-l-pyroglutamic acid (Fru-pGlu) were the highest among the APs and the level of Fru-pGlu was similar to that of Fru-Lys. Furthermore, fermentation periods of up to six months greatly influenced AP levels in soy sauce but the levels remained constant thereafter. Thermal treatment of soy sauce had little effect on AP levels.
Research and Development Division, Kikkoman Corporation, 399 Noda, Noda-City, Chiba 278-0037, Japan. Electronic address: hkata@mail.kikkoman.co.jp.
Hiroshi
H
Katayama
Research and Development Division, Kikkoman Corporation, 399 Noda, Noda-City, Chiba 278-0037, Japan.
Yuki
Y
Tatemichi
Research and Development Division, Kikkoman Corporation, 399 Noda, Noda-City, Chiba 278-0037, Japan.
Ayako
A
Nakajima
D002853:Chromatography, Liquid / Q000379:methods; D005504:Food Analysis / Q000379:methods; D006017:Glycolipids / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D045730:Soy Foods / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods
D006017:Glycolipids; C511949:N-(1,6-dideoxyfructopyranosyl)-1,3-dioleoyl-2-phosphatidylethanolamine; D010714:Phosphatidylethanolamines
Amadori products; LC–MS; Maillard reaction; Soy sauce