LACTASE IMMOBILIZATION WITH ENTRAPMENT METHOD USING CALCIUM ALGINATE MATRIX FOR LACTOSE HYDROLYSIS APPLIANCE

People with lactose intolerance are limited to consume milk and milk derived products. Therefore, it is important to develop lactose hydrolysis system by lactase. The focus of this research is to find the best method to stabilize the enzyme and to design a household appliance which can be applicated for lactose hydrolysis. Technically it is very difficult to separate the enzyme from their products and get back the active enzyme at the end of the reaction, so the enzyme immobilization is conducted. Lactase immobilization on alginate performed by entrapment method. The study was conducted to determined best alginate concentration for immobilization and to design a simple appliance for lactose hydrolysis. The best alginate concentration was found to be 2% (w/v) giving immobilization efficiency of 98.31 ± 0.29%. Time required to reduce lactose concentration to ± 1% b/v based on the design of tools made with 90 mg enzymes and 150 ml substrate was 5 hours. Free lactase activity was 0.049 ± 0.001 mol/min and immobilized lactase activity was 0.004 ± 0.0004 mol/min. The Km values of the immobilized lactase was 17.18% and the Vmax value was 0.246% / min. Km values of the free lactase was 3.45% and the Vmax value was 0.292%/min. The activity of the immobilized lactase was decreased in the second cycle by 12% of the initial value