Kinetic studies and mathematical model for sucrose conversion by Aspergillus niger fructosyl-transferase under high hydrostatic pressure.
The effect of pressure on the kinetically controlled synthesis reaction catalyzed from sucrose by Aspergillus niger fructosyl-transferase was investigated at pH 5.5 and 40 degrees C. The overall reaction was split up into five main reactions that were studied under pressure in initial rate conditions with various substrate concentrations in the absence or in the presence of glucose 50 g/l. A global reaction model was worked out according to the mathematical expression of the initial rates as the products of a polynomial rational function of substrate concentration and a corrective term introducing pressure. Experimental data from sugar concentrations were correctly described by the model during the course of the reaction under pressure. Raising the pressure induced a decrease in fructo-oligosaccharides yield by inhibiting the main transfer reaction without affecting sucrose hydrolysis.