Food processing by pulsed electric fields. I. Physical aspects

Abstract High voltage (10–50 kV·cm−1) and very short (< 10 μs) electric pulses can be used to pasteurize fluid foods at low or moderate temperatures apparently without significant sensorial quality changes. The main components of a pulsed electric field system are the high voltage‐high current switches, and the static or continuous treatment chambers with plate or coaxial parallel electrodes. The respective energy and other characteristics of pulses with constant polarity (exponential decay or square wave) or pulses with reversing polarity are discussed. The few existing industrial or research systems which are commercially available are indicated. The main independent process parameters are: voltage across the capacitors; number of capacitors; in‐terelectrode gap; number and frequency of pulses; food resistivity; food flow rate in the treatment chamber. Variations of these parameters influence the electric field, the width, and the energy of each pulse and the rate of ohmic heating of the food. The usual...