57] Lactose reduction of milk by fiber-entrapped β-galactosidase. Pilot-plant experiments

Abstract

Milk treated by enzymatic methods retains its original nutritional value because glucose and galactose, the products of lactose hydrolysis, are not removed. Moreover, the enzymatic process is particularly well adapted for immobilized lactase preparations. Because milk is a food, it is of the utmost importance not to transform any of its components, in this case lactose, into harmful substances, nor to add anything to the processed milk, nor to change the properties of milk. Furthermore, because of widespread lactose intolerance a very inexpensive industrial process is needed to increase milk consumption. Otherwise, the low lactose dairy products will be available for only a limited few. Now, the only inexpensive process involves using immobilized enzymes. This chapter discusses problems involved in the utilization of fiber-entrapped lactase for the industrial production of milk having low lactose content. The properties of enzymes from two different sources, E. coli and yeast, were studied and compared; then the behavior of some fiber-entrapped preparations and the problems relating to industrial application were investigated. Finally, pilot-plant experiments were carried out to establish optimal operating conditions.