Lactose hydrolysis in milk by immobilized β-galactosidase

The intolerance of a large number of children and adults for the lactose containing products caused a wide spread of investigations of the decrease of this bisaccharide in meals carried out by the application of such enzymes as β-galactosidases. The properties of four different commercial preparations of β-galactosidase originating from bacteria and fungi are described. The native enzymes are compared with their immobilized forms. pH and temperature optimalization and stability curves are presented not only for the immobilized enzymes but also for those which were additionally cross-linked with glutaraldehyde or bis-oxirane. Lactozym 3000 in an immobilized form seems to be the most useful for the delactatic process of commercially available milk.