PASTEURIZATION EFFICIENCY OF A HTST SYSTEM FOR HUMAN-MILK

An economical, small scale heat processing device was studied for rapi d and efficient pasteurization of human milk while preserving immunogl obulins A,G and M. Using a continuous flow HTST milk pasteurizer, huma n milk inoculated with E. coli (10(6) CFU/mL) or S. aureus (10(7) CFU/ mL) was heated at 71 degrees C at flow rates of 5.9, 12.3 and 18.9 mL/ min. All conditions completely inactivated both microorganisms and res ulted in negative alkaline phosphatase activity indicating complete pa steurization. Heat processing of bovine milk at 71 degrees C, at 5.9 m L/min resulted in retention of 30% of the gamma-glutamyl transpeptidas e (GGTP) activity. Lower residual activity could therefore indicate ov er pasteurization. Pasteurization at 71 degrees C for 9.0 sec (12.3 mL /min) resulted in retention of 74% of IgA, 75% IgG, and 68% IgM.