Immobilization of inulinase on concanavalin A-attached super macroporous cryogel for production of high-fructose syrup

In this study, concanavalin A (Con A)-attached poly(ethylene glycol dimethacrylate) [poly(EGDMA)] cryogels were used for immobilization of Aspergillus niger inulinase. For this purposes, the monolithic cryogel column was prepared by radical cryocopolymerization of EGDMA as a monomer and N,N′-methylene bisacrylamide as a crosslinker. Then, Con A was attached by covalent binding onto amino-activated poly(EGDMA) cryogel via glutaraldehyde activation. Characterization of cryogels was performed by FTIR, EDX, and SEM studies. Poly(EGDMA) cryogels were highly porous and pore size was found to be approximately 50-100 μm. Con A-attached poly(EGDMA) cryogels was used in the adsorption of inulinase from aqueous solutions. Adsorption of inulinase on the Con A-attached poly(EGDMA) cryogel was performed in continuous system and the effects of pH, inulinase concentration, and flow rate on adsorption were investigated. The maximum amount of inulinase adsorption was calculated to be 27.85 mg/g cryogel at 1.0 mg/mL inulinase concentration and in acetate buffer at pH 4.0. Immobilized inulinase was effectively used in continuous preparation of high-fructose syrup. Inulin was converted to fructose in a continuous system and released fructose concentration was found to be 0.23 mg/mL at the end of 5 min of hydrolysis. High-fructose content of the syrup was demonstrated by thin layer chromatography.