Abstract
Pulsed electric field (PEF)-treated milk (25.7 kV/cm for 34 mu s after preheating to 55 degrees C and holding for 24 s) was microbiologically stable for 21days at 4 degrees C, and similar to thermally treated milk (63 degrees C for 30 min or 73 degrees C for 15 s). Alkaline phosphatase inactivation was comparable after PEF (preheating followed by PEF) and both thermal treatments. PEF treatment initially reduced xanthine oxidase (30%) and plasmin (7%) activities, but after 21 days of refrigerated storage these activities were similar to the initial untreated milk. During refrigerated storage of PEF (preheating followed by PEF) and thermally treated milk, lipolytic activity increased and pH levels decreased.