Kinetics of maltooligosaccharide hydrolysis in subcritical water

The kinetics of the hydrolysis of maltooligosaccharides with a degree of polymerization ( DP) of 3- 6 in subcritical water was studied using a tubular reactor at temperatures between 200 and 260 degrees C and at a constant pressure of 10 MPa. The maltooligosaccharide disappearance and product formation at residence times shorter than 50 s could be expressed by first- order kinetics. The rate constants for the hydrolysis of each maltooligosaccharide were evaluated. There was a tendency that the exosite glucosidic bond was hydrolyzed faster than the endo- site one irrespective of the DP of the maltooligosaccharide. The hydrolysis of the maltooligosaccharides was consecutively preceded, and the time dependence of the hydrolysis for maltooligosaccharides with different DPs could be calculated by simultaneously solving the mass balance equations for all the possible saccharides.