Formation mechanism of volatile and non-volatile compounds in peptide-xylose Maillard reaction

The mechanism of volatile and non-volatile compounds formed from model reactions of 3 peptides from beef protein hydrolysate, with cysteine, [C-13(5)] xylose/xylose (1:1) and thiamine, heated at 140 degrees C for 90 min, were analyzed respectively with GC-O-MS and ESI Q-TOF MS. The carbohydrate module labeling (CAMOLA) method was used to analyze and identify the formation pathways of volatiles and non-volatiles. Only one nitrogen-containing heterocyclic compounds 1-(2-furanylmethyl)-1H-pyrrole was identified in this study. Analysis of the mass spectra showed that the carbon skeleton furfural, 2-butyl-furan 2,3-dihydrofuran, thiophene, 2-methoxy-5-methyl-thiophene stem from xylose. It was proposed that (Gly-Val-Thr-Val-Phe-Glu-Asp-Leu-Lys) could be capable of splitting in the position of aspartyl and prolyl and then formed cyclic (Leu-Lys). The compounds with high m/z values of 320 were formed by cross-linking peptide and xylose. (C) 2013 Elsevier Ltd. All rights reserved.