RHIZOPUS-ARRHIZUS LIPASE-CATALYZED INTERESTERIFICATION OF PALM OIL MIDFRACTION IN A GAS-LIFT REACTOR

Celite-immobilized lipase from Rhizopus arrhizus was encapsulated in l ecithin reverse micelles and used to interesterify triacylglycerols of palm oil midfraction with stearic acid in n-hexane. The reaction kine tics were studied in a gas-lift reactor with an internal draft tube. T he equilibrium state was reached more rapidly in the gas-lift reactor (9 h) than in comparative shake-flask studies (12 h). A 2.8-fold incre ase in the productivity of interesterification by Celite-immobilized a nd lecithin-protected lipase was achieved in the gas-lift reactor when compared with shake-flask experiments. The high productivity of the e nzymatic inter esterification was attributed to the combined effects o f enzyme immobilization and reactor design.