Abstract
Bacterial count reduction and enzyme inactivation in bovine whole milk by pulsed electric field (PEF) processing combined with pre-heating and intermediate cooling was compared with that induced by thermal treatments (maximum of 63 degrees C for 30 min and 73 degrees C for 15 s). Milk was pre-heated to 55 degrees C for 24 s and PEF-treated in continuous mode at electric field intensities of 15.9-26.2 kV cm(-1) for 17-101 mu s. PEF treatments reduced the number of inoculated (8.3 log cfu mL(-1)) Escherichia coli and Listeria innocua to less than 2 log cfu mL(-1). PEF treatments at 20.7-26.2 kV cm(-1) reduced the total plate count and indigenous alkaline phosphatase activity to a level similar to that measured following thermal treatments. Treatment at 26.1 kV cm(-1) for 34 ms, combined with pre-heating, reduced the activity of plasmin, xanthine oxidase and lipolysable fat by 12%, 32% and 82%, respectively, compared with raw milk. (C) 2014 Elsevier Ltd. All rights reserved.