Enzymes play a pivotal role in catalyzing diverse reactions. However, their instability upon repetitive/prolonged use, as well as their inhibition by high substrates and product concentration, remains an area of concern. In this study, porcine pancreatic ${alpha}$-amylase was immobilized on magnetic $Fe_2O_3$ nanoparticles ($Fe_2O_3$-NPs) in order to hydrolyze starch. The magnetic nanoparticle bound enzymes retained 94% of their initial enzyme activity. X-ray diffraction and atomic force microscopy analyses showed that the prepared matrix had advantageous microenvironment and a large surface area for binding significant amounts of protein. Functional groups present in enzyme and support were monitored by Fourier transform infrared spectroscopy. Immobilized enzyme exhibited lowered pH optimum (pH 6.0) to a greater degree than its soluble counterpart (pH 7.0). Optimum temperature for the immobilized enzyme shifted towards higher temperatures. The immobilized enzyme was significantly more resistant to inactivation caused by various metal ions and chemical denaturants. Immobilized ${alpha}$-amylase hydrolyzed 92% starch in a batch process, after 8 h at $40^{circ}C$; while the free enzyme could hydrolyze only 73% starch under similar experimental conditions. A reusability experiment demonstrated that the immobilized enzyme retained 83% of its original activity even after its $8^{th}$ repeated use.