1. Effects of divalent cations on the formation of 4(5)-methylimidazole in fructose/ammonium hydroxide caramel model reaction. Author Wu X, Yu D, Kong F, and Yu S Subjects Carbohydrates, Maillard Reaction, Ammonium Hydroxide chemistry, Candy analysis, Cations, Divalent metabolism, Fructose chemistry, Imidazoles chemistry Abstract The objective of the present study was to detail the changes of 4(5)-methylimidazole (4-MI) and its precursors in the presence of divalent cations (Ca(2+), Mg(2+)) in a fructose/ammonium hydroxide caramel model system. The content of 4-MI and its precursor methylglyoxal (MGO) was inhibited by divalent cations (Ca(2+), Mg(2+)). The possible explanation might be that fructose and its Heyns product glucosamine interact with divalent cations to form complexes and inhibit the degradation of glucosamine into MGO. Moreover, the changes of fructose, NH4(+) and brown intensity in the presence of divalent cations indicated that fructose and glucosamine underwent intra-intermolecular polymerisation into melanoidins rather than the degradation reaction into aldehydes and ketones., (Copyright © 2016 Elsevier Ltd. All rights reserved.) Published 2016 Full Text View/download PDF