Kinetics of the sulphite-inhibited browning of fructose: effect of buffer

The rate of loss of S(IV) in mixtures of fructose-glycine-S(IV) and fructose-S(IV) is increased by the presence of acetate buffer. The conversion of fructose into a reaction intermediate is catalysed by the buffer components. In the presence of glycine, catalysis is due to the acetate ion, and the effect of glycine and acetate on the rate of loss of S(IV) may be additive. The pH of the reaction mixture was found to have a small effect on the rate of S(IV) loss; the order with respect to [H+]is c. 0.4.