SEPARATION OF MAILLARD REACTION-PRODUCTS FROM XYLOSE-GLYCINE AND GLUCOSE-GLYCINE MODEL SYSTEMS BY CAPILLARY-ELECTROPHORESIS AND COMPARISON TO REVERSE-PHASE HPLC

Capillary electrophoresis (CE) and reverse phase HPLC were used to ana lyse Maillard reaction products (MRPs) formed in refluxed, aqueous xyl ose-glycine and glucose-glycine model systems. CE was shown to resolve many more components than reverse phase HPLC. Ultrafiltration was use d to separate the MRPs into three molecular weight fractions, nominall y > 3000, between 3000 and 1000, and < 1000 daltons. Components of the lowest molecular weight fraction migrated as sharp, well-resolved pea ks by CE, whereas the components of the higher molecular weight fracti ons (melanoidin) migrated as a single broad peak in each case. The mel anoidin and the majority of the low molecular weight compounds migrate as anions in berate buffer at pH 9.3, some of this anionic character being due to complexation with berate. The majority of colour in the s ystems was attributed to the melanoidin, with only two other CE peaks in the xylose-glycine, and one in the glucose-glycine systems having s ignificant absorbancies in the visible region. (C) 1998 Elsevier Scien ce Ltd. All rights reserved