title: Characterisation of Maillard reaction products derived from LEKFD--a pentapeptide found in β-lactoglobulin sequence, glycated with glucose--by tandem mass spectrometry, molecular orbital calculations and gel filtration chromatography coupled with continuous photodiode array.
abstract: Maillard reaction peptides (MRPs) contribute to taste, aroma, colour, texture and biological activity. However, peptide degradation or the cross-linking of MRPs in the Maillard reaction has not been investigated clearly. A peptide of LEKFD, a part of β-lactoglobulin, was heated at 110 °C for 24h with glucose and the reaction products were analysed by HPLC with ODS, ESI-MS, ESI-MS/MS and HPLC with gel-filtration column and DAD detector. In the HPLC fractions, an imminium ion of LEK*FD, a pyrylium ion or a hydroxymethyl furylium ion of LEK*FD, and KFD and EK were detected by ESI-MS. Therefore, those products may be produced by the Maillard reaction. The molecular orbital of glycated LEKFD at the lysine epsilon-amino residue with Schiff base form was calculated by MOPAC. HPLC with gel-filtration column showed cross-linking and degradation of peptides.
authors.affiliation: Department of Food and Nutrition, Japan Women's University, Bunkyo-ku, Tokyo 112-8681, Japan. Electronic address: yama-k@fc.jwu.ac.jp.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Homma
authors.forename: Yuri
authors.initials: Y
authors.lastname: Nomi
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Otsuka
mesh_terms: D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004151:Dipeptides / Q000032:analysis / Q000737:chemistry; D055664:Electrochemical Techniques; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry*; D006031:Glycosylation; D006358:Hot Temperature; D007782:Lactoglobulins / Q000032:analysis / Q000737:chemistry*; D015416:Maillard Reaction; D008958:Models, Molecular; D009842:Oligopeptides / Q000032:analysis / Q000737:chemistry*; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry*; D011487:Protein Conformation; D055550:Protein Stability; D059748:Proteolysis; D012545:Schiff Bases / Q000032:analysis / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D004151:Dipeptides; D006023:Glycoproteins; D007782:Lactoglobulins; D009842:Oligopeptides; D010446:Peptide Fragments; D012545:Schiff Bases
keywords: Maillard reaction; Modified peptide; β-Lactoglobulin