LIPOSOMAL ENCAPSULATION OF BETA-GALACTOSIDASE - EFFECT OF BUFFER MOLARITY, LIPID-COMPOSITION AND STABILITY IN MILK

Beta-Galactosidases from E. coli and Aspergillus flavus were encapsula ted in liposomes using the reverse-phase evaporation method. There was an inverse relationship between buffer molarity and encapsulation eff iciency. The presence of cholesterol and stearylamine or dicetylphosph ate along with phosphatidyl choline increased encapsulation efficiency significantly. Liposomes containing either bacterial or fungal beta-g alactosidase were stable in buffer as well as freshly pasteurized milk for up to 20 days at 4C Lactose hydrolysis was negligible in milk con taining liposomes with bacterial beta-galactosidase, while there was s ignificant (25%) hydrolysis of lactose in milk containing liposomes wi th fungal beta-galactosidase during 20 days of storage at 4C Results o f this study suggest that liposomes containing beta-galactosidase can be prepared and added to milk without affecting the lactose content fo r up to 20 days of refrigeration (4C).