A mass transport/kinetic model for the description of inulin hydrolysis by immobilized inulinase

BACKGROUND: Inulin is a polydisperse carbohydrate consisting of (2→1) fructosyl–fructose links; at one end of the molecule,a glucose residue may be present. The enzymatic hydrolysis of inulin by inulinase represents a promising alternative for theproduction of fructose and fructo-oligosaccharides (FOS)However, the studies reported in the literaturedonot take into accountthe variability ofmolecular weight of the inulin, which significantly affects the kinetics of bioconversion.RESULTS: In this paper a mass transport/kinetic model is proposed with the aim of describing inulin enzymatic hydrolysiscatalyzed by immobilized inulinase. The proposed model takes into account both kinetic and mass transfer phenomena andquantified their respective significance through the evaluation of the effectiveness factor. The model was able to predictthe effect of molecular weight and poly-dispersity of inulin on both enzyme intrinsic kinetics and mass transfer. This wasconfirmed by a favourable comparison between a set of experimental results and model predictions, which offered a realisticrepresentation of system behavior over a wide range of operating conditions.CONCLUSION: Although developed with reference to inulin hydrolysis, the proposed approach, due to its versatility andgenerality, can also be applied to model the enzymatic hydrolysis of different types of polysaccharides.