Partially purified maltase was mixed with equal volume (1:1) of sodium alginate (4.0%) and added drop wise into calcium chloride solution (0.2 M) with constant shaking on ice bath. Immobilized enzyme and control beads were hardened by storing them into fresh 0.2 M calcium chloride solution for 90.0 min at 4 °C. The beads were washed with deionized water and potassium phosphate buffer to remove any unbound enzyme molecules.