CATALYST FOR SYNTHESIZING LACTULOSE AND METHOD OF SYNTHESIZING LACTULOSE

摘要

PURPOSE: A lactulose synthetic catalyst is provided to cheaply and continuously produce lactulose using whey instead of expensive purified lactose and to improve economic efficiency of processes. CONSTITUTION: A lactulose synthetic catalyst contains glucose isomerase and beta-galactosidase fixed at a carrier. Whey is used as a substrate of the catalyst and contains 9-25 %(w/v) of lactose. The ratio between a beta-galactosidase unit (U) and a glucose isomerase unit (U) is 1:1-1:6. Beta-galactosidase and glucose isomerase are fixed at the carrier by a covalent bond. A method for preparing lactulose comprises the steps of: fixing beta-galactosidase and glucose isomerase at the carrier; and reacting with the substrate including whey. [Reference numerals] (AA) Lactulose concentration; (BB) Lactose conversion rate; (CC) Lactulose concentration(g/L); (DD) Lactose conversion rate(%); (EE) Lactose concentration(%(w/v))