Characterization of melanoidins from a glucose-glycine model system

The properties of melanoidins prepd. from glucose and glycine (GG) were investigated by a three step purifn. protocol consisting of dialysis, gel filtration at high ionic strength and ion metal affinity chromatog. The high mol. wt. fraction obtained in the GG system is responsible for 80% of the total brown color and its antioxidative ability was about 1/4 of that of Trolox measured by the inhibition of linoleic acid oxidn. GG melanoidins have good affinity towards Cu (II) (32% bound to the resin) while it is much lower towards Pb (II) (10%) and Fe (II) (5%). Capillary zone electrophoresis anal. suggests that GG melanoidins are pos. charged, although no signal was obsd. analyzing melanoidins by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF/MS).