APPLICABILITY OF ALGINATE ENTRAPPED YEAST CELLS FOR THE PRODUCTION OF LACTOSE-HYDROLYZED MILK

To overcome the problem of enzyme extraction and poor permeability of cell membrane to lactose, permeabilized Kluyveromyces marxianus NCIM 3465 cells as a source of β‐D‐galactosidase were employed for the production of lactose‐hydrolyzed milk. In view of the advantages of an immobilized cell system over a free cell system, the yeast cells were entrapped in alginate gel for their subsequent use in lactose hydrolysis. Different process parameters (alginate concentration, bead size, biomass load, temperature, agitation and incubation time) were monitored to enhance lactose hydrolysis in milk. Maximum lactose hydrolysis (87.9%) was observed with yeast cells immobilized in 2% (w/v) alginate concentration with a bead size of 2.90 mm at 30C under agitation (80 rpm) after 150 min of incubation. The developed system was highly stable and the alginate entrapped yeast cells can be recycled up to the eight cycle without any marked change in their ability to carry out the lactose hydrolysis.