Multi-purpose immobilization of lipase onto modified magnetic nanoparticles: Characterization and enhancement of enzymatic interesterification

Improving catalytic performance represents a highly desirable but challenging objective for the immobilization of biocatalysts. A novel biocatalyst of ANL@Fe 3 O 4 -SiO 2 -APTES was fabricated by immobilizing Aspergillus niger lipase (ANL) onto amino-alkyl group-modified magnetic nanoparticles. This biocatalyst exhibited an enzyme loading of 127.68 mg/g and the specific activity of 1132.26 U/g. The superior activity and recyclability of ANL@Fe 3 O 4 -SiO 2 -APTES was validated. The outstanding performance for the enzymatic interesterification (EIE) of palm stearin (PS) and rice bran oils (RBO) was observed. The significantly decreased the solid fat content (SFC) and enhanced crystallization rate of oils was achieved, as well as the β' type of oils after EIE was obtained. Moreover, molecular dynamics simulations were conducted to elucidate the underlying catalytic mechanism of EIE. This study proposes a highly efficient and sustainable approach for the chemical modification of lipids, thereby promoting its broad application in the food industry.