Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry

Antonio Dario Troise; Alberto Fiore; Markus Wiltafsky; Vincenzo Fogliano

doi:10.1016/j.foodchem.2015.04.137

Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry

Food Chem. 2015 Dec 1:188:357-64. doi: 10.1016/j.foodchem.2015.04.137. Epub 2015 Apr 30.

Authors

Antonio Dario Troise¹, Alberto Fiore², Markus Wiltafsky³, Vincenzo Fogliano⁴

Affiliations

¹ Food Quality Design Group, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands; Department of Agricultural and Food Science, University of Napoli "Federico II", Parco Gussone, 80055 Portici, Napoli, Italy. Electronic address: antonio.troise@wur.nl.
² School of Science, Engineering & Technology, Division of Food Science, Abertay University, Dundee DD1 1HG, UK.
³ Evonik Industries AG, Rodenbacher Chaussee 4, 63457 Hanau, Germany.
⁴ Food Quality Design Group, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands.

PMID: 26041204
DOI: 10.1016/j.foodchem.2015.04.137

Abstract

The control of Maillard reaction (MR) is a key point to ensure processed foods quality. Due to the presence of a primary amino group on its side chain, lysine is particularly prone to chemical modifications with the formation of Amadori products (AP), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL). A new analytical strategy was proposed which allowed to simultaneously quantify lysine, CML, CEL and the Nε-(2-Furoylmethyl)-L-lysine (furosine), the indirect marker of AP. The procedure is based on stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry. It showed high sensitivity and good reproducibility and repeatability in different foods. The limit of detection and the RSD% were lower than 5 ppb and below 8%, respectively. Results obtained with the new procedure not only improved the knowledge about the reliability of thermal treatment markers, but also defined new insights in the relationship between Maillard reaction products and their precursors.

Keywords: CEL; CML; Furosine; LC–MS/MS; Lysine; Lysine (PubChem CID: 5962); Maillard reaction; Nε-(2-Furoylmethyl)-l-lysine (furosine, PubChem CID: no items); Nε-(Carboxyethyl)-l-lysine (CEL, PubChem CID: no items); Nε-(Carboxymethyl)-l-lysine (CML, PubChem CID: 123800).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chromatography, Liquid
Food Analysis / methods*
Indicator Dilution Techniques
Isotopes
Lysine / analogs & derivatives*
Lysine / analysis*
Protein Conformation
Quality Control
Reproducibility of Results
Tandem Mass Spectrometry*

Substances

Isotopes
furosine
N(6)-(1-carboxyethyl)lysine
N(6)-carboxymethyllysine
Lysine