Analysis of Furanone, Pyranone, and New Heterocyclic Colored Compounds from Sugar−Glycine Model Maillard Systems

Abstract

Aqueous sugar (xylose or glucose)-glycine model systems were refluxed for 2 h with the pH maintained at 5. Reverse-phase HPLC of the total reaction products gave two resolved peaks (one of which was colored) for the xylose system and five resolved peaks (two of which were colored) for the glucose system. The components responsible for these peaks were isolated from the ethyl acetate extracts by semipreparative HPLC. Using mainly NMR, the colored compound from the xylose system was identified as the new 2-acetyl-6-(hydroxymethyl)-5,6-dihydro-4H-pyridinone. The colored compounds from the glucose system were most likely to be two novel cis/trans ring isomers of the related new compound 2-acetyl-6-hydroxy-7-(hydroxymethyl)-1,5,6,7-tetrahydro-4H-azepinone+ ++. These compounds are the first one-ring structures isolated from sugar-amino acid model systems that are reported to be colored. Two of the colorless components of the glucose system were identified, mainly by NMR experiments, as the related compounds 4-hydroxy-2-(hydroxymethyl)-5-methyl-3(2H)-furanone and 2, 3-dihydro-3,5-dihydroxy-6-methyl-4H-pyranone. The remaining compound from the glucose system and the colorless compound from the xylose system were identified as 5-(hydroxymethyl)furfural and 4-hydroxy-5-methyl-3(2H)-furanone, respectively.

Melanoidins produced by the Maillard reaction: Structure and biological activity

“…1G) or azepinone (Fig. 1H), were also isolated from the acidic xylose-glycine and glucose-glycine systems (refluxing for 2 h at pH 5), respectively (Ames, Bailey et al, 1999). Moreover, Tressl et al (1998) reported an N-substituted pyrrole polymer chromophore with extraordinary polycondensation activity ( Fig.…”

“…Although numerous attempts have been undertaken to isolate and purify melanoidins from foods such as bread crust (Lindenmeier & Hofmann, 2003;Lindenmeier et al, 2002) and coffee (Bekedam et al, 2006;Bekedam, Loots et al, 2008;Bekedam, Roos et al, 2008;Gniechwitz et al, 2008), as well as from sugar-amino acid model systems (Ames, Bailey, & Mann, 1999;Frank & Hofmann, 2000;Hofmann, 1998bHofmann, , 1998cTressl, Wondrak, Kruger, & Rewicki, 1998), little is known about the overall structural properties of melanoidins .…”

Determination of the molecular weight distribution of non-enzymatic browning products formed by roasting of glucose and glycine and studies on their effects on NADPH-cytochrome c-reductase and glutathione-S-transferase in Caco-2 cells

“…Depending on their molecular weight, the coloured components affecting this non-enzymatic browning may be divided into two classes, i. e. the low-molecular weight coloured compounds, consisting of up to 4 linked rings with a molecular weight below 1 000 Da [1][2][3][4][5][6], and the highmolecular melanoidins, which are assumed to be water-soluble, coloured polymers with masses of up to 150 000 daltons.…”

“…In particular, the browing reaction between glucose and glycine has been thoroughly investigated, e. g. by Maillard [13,14], Mc Weeny et al [15], Gomyo et al [16], Motai [17], Motai and Inoue [18], Hayase and Kato [19], Homma et al [20], Hayase et al [21], Kim et al [22], Kim and Park [23], Kato et al [24 -27], Obretenov et al [28], Wedzicha and Vakalis [29], Taguchi and Sampei [30], Feather and Nelson [31], Benzing-Purdie et al [32], Nam and Kim [33], Ames et al [2], Wedzicha and Kaputo [34,35], and recently by Cämmerer and Kroh [36]. In general, the reaction conditions reported in the literature for most of the experiments are not suitable to simulate food processing conditions.…”

Novel approaches to the analysis of the Maillard reaction of proteins

“…Most of the methods developed for studying the Maillard reaction have concentrated on the reaction between small molecules, particularly amino acids and monosaccharides [5][6][7][8]. The few studies of the Maillard reaction with proteins, specifically food proteins, have generally relied upon analysis after an acidic digest, potentially creating artefactual results (e.g., [9,10]).…”