Immobilization and biochemical characterization of porcine pancreatic lipase on a magnetic metal-organic framework (mZIF-67) and its application in the synthesis of butyl acetate.

Lipase synthesis of flavor esters is one of the main approaches for their sustainable production. In the present study, porcine pancreatic lipase (PPL) was immobilized on a magnetic zeolite imidazole framework (mZIF-67) to improve its biochemical properties. Techniques such as SEM, EDX, FTIR, TEM, and XRD were used to characterize the PPL@mZIF-67 (the enzyme immobilized on the support). Notably, after 4 h of incubation at 60 °C, PPL@mZIF-67 showed 90 % of its initial activity, while the free enzyme showed only 35 % activity, indicating a 6.5-fold improvement in the thermal stability of the enzyme. PPL@mZIF-67 also maintained 87 % activity at pH 9.0, while this was only 57 % for the free lipase, indicating a 3.3-fold increase in stability at pH 9. The thermal inactivation results showed that the t1/2 of the immobilized lipase was 5.4 and 1.86 times higher than that of free PPL at 30 and 40 °C, respectively. The immobilized lipase showed better resistance to organic solvents and detergents and had a 30 % increase in stability in the presence of isopropanol and dimethylformamide. The conversion efficiency of butyl acetate using PPL@mZIF-67 was 85 % after 48 h of incubation, while the conversion efficiency of the free enzyme was 50 % under the same conditions. These results indicated the high potency of porcine pancreatic lipase in mZIF-67 in the synthesis of flavor esters.