IMMOBILIZATION OF COMMERCIAL PECTINASE (POLYGALACTURONASE) ON CELITE AND ITS APPLICATION IN JUICE CLARIFICATION

摘要

The commercial pectinase (polygalacturonase) was immobilized on celite throughrnadsorption. There was 2.5% concentration of glutaraldehyde used as cross-linkingrnagent and a binding time of 4 h was found to be the best time for its properrnbinding. Binding efficiency of enzyme to the matrix was 43.18%. The immobilizedrnenzyme retained almost 50% of activity after third cycle of reuse. Free enzymernshowed maximum activity with polygalacturonic acid (PGA, 0.9%) as substrate atrn40C temperature, pH 5.5 and incubation time of 20 min while immobilizedrnenzyme showed maximum activity with PGA (0.9%) as substrate at temperaturernof 45C, pH 5.5 and incubation time of 15 min. Both free and immobilized enzymernwere inhibited by metal ions, thiols, phenolics and protein inhibitors. For clarification of 1.0 mL of pineapple juice, 20 mg of immobilized enzyme per mL of juicernat 45C temperature and 1 h of holding time was optimized.