Novel insights into the maillard catalyzed degradation of maltose

Numerous investigations concerning Maillard degradation of carbohydrates clearly depict the important impact of α-dicarbonyl compounds on changes occurring during preparation of food or physiological processes in vivo. To study the formation of these reactive intermediates during degradation of maltose in the presence of lysine, α-dicarbonyl compounds were isolated, identified and quantified after reaction with o-phenylenediamine to form their stable quinoxaline derivatives. Maltosone and 1,4-dideoxyglucosone were synthesized and incubated independently with lysine to investigate follow-up products and to gain further insights into the complex degradation mechanisms. Glyoxylic acid as a dicarbonyl structure and 5,6-dihydroxy-2,3-dioxohexanal as a 1,2,3-tricarbonyl compound were established as novel Maillard degradation products of maltose. Conducted experiments unequivocally demonstrated that inter- and intramolecular redox reactions are of major importance during degradation of disaccharides. 1,4-Dideoxyglucosone, 1-lysino-1,4-dideoxyglucosone, 5,6-dihydroxy-2,3-dioxohexanal, 3,4-dideoxypentosone and glyoxylic acid were found to be the central intermediates involved in the redox chemistry. With the present study we deliver a comprehensive overview on the mechanisms behind α-dicarbonyl compounds evolving from Maillard degradation of maltose.