Abstract
Transfructosylation catalyzed by fructooligosaccharide-producing b-fructofuranosidase from Aspergillus niger ATCC 20611 was kinetically studied and a reaction model of transfructosylation was proposed. Kinetic parameters (Vm, Km, and Ki) were determined from experimental data on the transfructosylation rates at various substrate concentrations with and without addition of glucose. Transfructosylation reaction was found to be inhibited non-competitively (Ki=0.12 mol l−1) by glucose. Simulation results in sugar composition due to the action of a β-fructofuranosidase were in good agreement with the experimental data. In order to get higher reaction conversion with a simultaneous removal of glucose, a membrane reactor system was developed using nano-filtration membrane, through which glucose permeated but sucrose and fructooligosaccharides did not permeate. Fructooligosaccharide percentage of the reaction product was increased to above 90%, which was much higher than that of the batch reaction product (55–60%) and comparable to that of the chromatography processed product. The membrane reactor system will be applicable for production of fructooligosaccharides.
