The rating of fructose caramelization as a percentage of the overall brown color intensity of the lysine-containing fructose solution between pH 4.0 and pH 7.0 was found to be between 10 and 36%. These values were lower than those obtained by Buera and others (1987) in an aqueous glycine-fructose model system heated to 55 8C, which were 25% and 43% at pH 4.0 and pH 6.0, respectively. It should be noted, however, that a 4-fold molar excess of fructose with regard to lysine was used in their study and that in addition the reactivity of lysine and glycine may not be the same.