Effect of storage on mutagenicity, absorbance and content of furfural in the ribose-lysine maillard system.

The stability with time of browned mixtures characterized by different water activities (aw 0.98, 0.84 and 0.60) and heating temperatures (100, 120, 140 and 160 degrees C) was analysed using the ribose-lysine model system. The results obtained demonstrated the occurrence, during storage, of changes both in the composition of the browned mixtures and in their mutagenic properties, as detected with the Ames test. Only the browned mixtures obtained at 100 degrees C showed a progressive increase in mutagenicity during storage, matched by an increase in ultraviolet and visible light absorbance and of furfural content. In the browning mixtures characterized by a more advanced stage of the Maillard reaction, in which mutagenic activity had initially been found to be undetectable, such activity became evident during storage.