Formation and Structure of Melanoidins in Food and Model Systems

Abstract

Summary Melanoidins, the final products of the Maillard reaction, are of particular interest in food chemistry. This is due not only to their importance as food components but also to their biological activity. The present study was undertaken to find the connection between the low molecular weight products of thermal degradation of melanoidins, and the structures of the isolated polymers. The main volatile compounds formed by thermal degradation of food melanoidins and those formed in related model systems were identified by GC-MS. Heterocyclic compounds (mainly furans), alkyl phenols and other compounds were found. An attempt was made to elucidate the mechanism of melanoidin formation in L-ascorbic acid—α-amino acid model systems. The primary intermediates were isolated and identified. Heterocyclic compounds and some products of the retro-aldol degradation of the α-dicarbonyl compounds play a significant role. A certain amount of the same low molecular compounds was found both among the degradation products of model systems and food melanoidin (or their intermediates). An hypothesis about their participation in melanoidin structures is proposed.