Shelf life of whole milk processed by pulsed electric fields in combination with PEF-generated heat

摘要

Application of pulsed electric fields (PEF) in combination with mild thermal treatment was studied to extend the shelf life of whole milk. Five pulses with peak electric field strength of 35 kV/cm and pulse width of around 2.3 Vs were applied to milk at 65 degrees C and sustained for less than 10s. Shelf life of the milk was extended by a minimum of 24 days. A synergistic interaction between PEF and mild thermal treatment was found. Neither the severe PEF treatment applied at lower temperatures, nor the mild thermal treatment equivalent, including longer treatment times than used in this study, could significantly extend the shelf life of milk. However, the combination of both PEF and mild temperature extended milk's shelf life adequately. The useof a thermal regeneration system improved the energy efficiency of the studied preservation process making it highly competitive with pasteurization. (c) 2008 Published by Elsevier Ltd on behalf of Swiss Society of Food Science and Technology.