Four model solutions with the Maillard precursors methionine and glucose were reacted at 40 degrees C for up to 15 days. The solutions had a high or low precursor concentration leading to either high or medium water activity (0.96; 0.86). The water activity of the two other solutions was reduced by adding either salt or sucrose. Glucose, methionine and the Amadori compound (Fru-Met) were quantified after 1, 2, 6, 10 and 15 days. The results show that high salt and sucrose levels had a much more pronounced influence on glucose consumption and Fru-Met formation than differences in water activity. Glucose degradation and Fru-Met formation was favoured by high sucrose levels and inhibited by high NaCl levels. (C) 2010 Elsevier Ltd. All rights reserved.