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.