Potentialization of the lactoperoxidase system for preservation of raw milk in the tropics.

The antimicrobial ability of the lactoperoxidase system was increased by the addition of larger amounts of the thiocyanate and hydrogen peroxide at levels above those suggested by other authors. Results of laboratory and field trials revealed that the potentialized system was able to preserve poor-quality raw milk for longer periods of time, at "tropical" temperatures, than when used as recommended previously. It was possible to preserve some milks at 20 degrees C for more than one day, without diminishing their overall quality. At 36 degrees C, the milks did not show acidity development for about 10 hours. Tests conducted under real collection and transportation conditions validated these findings. It was therefore proved that the system can be used practically and that its bactericidal/bacteriostatic effect on the spoilage flora of milk can be increased in order to overcome the particularly adverse conditions of milk handling in the tropics.