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

BACKGROUNDInulin is a polydisperse carbohydrate consisting of (21) 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 the production of fructose and fructo-oligosaccharides (FOS) However, the studies reported in the literature do not take into account the variability of molecular weight of the inulin, which significantly affects the kinetics of bioconversion. RESULTSIn this paper a mass transport/kinetic model is proposed with the aim of describing inulin enzymatic hydrolysis catalyzed by immobilized inulinase. The proposed model takes into account both kinetic and mass transfer phenomena and quantified their respective significance through the evaluation of the effectiveness factor. The model was able to predict the effect of molecular weight and poly-dispersity of inulin on both enzyme intrinsic kinetics and mass transfer. This was confirmed by a favourable comparison between a set of experimental results and model predictions, which offered a realistic representation of system behavior over a wide range of operating conditions. CONCLUSIONAlthough developed with reference to inulin hydrolysis, the proposed approach, due to its versatility and generality, can also be applied to model the enzymatic hydrolysis of different types of polysaccharides. (c) 2014 Society of Chemical Industry