Maillard reaction chromophoric products

An effort has also been made to determine the structure of products providing coloration in the Maillard reaction prior to melanoidin formation. The reaction between D-xylose and isopropylamine in dilute acetic acid produced 2-(2-furfurylidene)-4-hydroxy-5-methyl-3(2/f)-furanone (116). This highly chromophoric product can be produced by the combination of 2-furaldehyde and 4-hydroxy-5-methyl-3(2//)-furanone (111) in an aqueous solution containing isopropylammonium acetate. The reaction between o-xylose and glycine at pH 6, under reflux conditions, also pro-duces " 116. Other chromophoric analogs may be present, including 117,... 

As part of extensive studies lasting over 30 years on the structures of chromophores involved in nonenzymatic browning reactions, two intensely orange, previously unknown, compounds have been identified (2R,8aR)-l and ZS, 8aR)-4-(2-furyl)-7-[(2-furyl)methylidene]-2-hydroxy-2//,7//,8a//-pyrano[2,3-3]pyran-3-one <1998CAR215>. Additional studies on the single Maillard reaction products of these compounds have also been reported <1998JFA3912>. 

The red pigment, obtained from the interaction of amino acids and dehydro-ascorbic acid and shown to have structure 31 (p. 54) by Kurata et al.,194 provides another model chromophore for Maillard reaction products. 

While low molecular weight chromophores arise mainly in systems with free amino acids, the coloured Maillard reaction products with proteins are almost exclusively macromolecular substances. 

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