Enhanced catalytic performance and reusability of ZnO-immobilized pectinase for continuous product yield in food Bioprocessing using response surface methodology

For improved operational stability and reusability, the enzyme was immobilized on zinc oxide nanoparticles. Optimal immobilization was achieved with 2000 U mg−1 pectinase using 2% glutaraldehyde after 150 min of cross-linking at 30 °C. The immobilized enzyme exhibited greater stability across wider pH and temperature. Kinetic analysis indicated that ZnO based immobilization did not cause major effect on the catalytic efficiency of pectinase (Free: 1.017 mg ml−1 min−1 (Km) and 23800 µmol L−1 min−1 (Vmax); Immobilized: 1.116 mg ml−1 min−1 (Km) and 20600 µmol L−1 min−1 (Vmax)). The free and immobilized pectinase was also compared for continuous degradation of pectin, and their yield was compared using response surface methodology (RSM). The contour and 3D plots showed marked difference in performance and stability of free and immobilized enzyme with product yield of 60 mg ml−1 and 180 mg ml−1 for free and immobilized pectinase respectively. These findings suggest that ZnO immobilized pectinase exhibit greater suitability for scale-up in continuous food bioprocessing applications.