Preparation and Characterization of PVA–SA Hydrogel Immobilized β‐Galactosidase With Improved Catalytic Properties

rose from 0.40 to 1.71 U/mg protein. Storage experiments demonstrated improved stability at 4°C, with about 60% of the initial activity retained after 8 weeks, whereas freezing at -20°C accelerated inactivation. The immobilized enzyme retained more than 80% of its catalytic performance after three consecutive uses and still preserved approximately 65% following the fourth cycle. Lactose hydrolysis experiments confirmed efficient and sustained performance, reaching 78% conversion after 180 min.