Influence of electric current density on the bactericidal effectiveness of pulsed electric field treatments

A procedure applying equivalent pulsed electric field (PEF) treatments of similar peak electric field intensity, total treatment time, and treatment temperature, while delivering different amounts of electric current, was successfully developed in this study. Listeria innocua suspended in McIllvaine buffer was subjected to five PEF treatments, each with a peak electric field intensity of 28.85 kV/cm applied for 60 μs at 44.3 °C, with peak electric currents of 1.94, 2.20, 2.76, 3.51, and 4.21 kA, respectively. To apply the described treatments, the charge voltage, pulsing frequency, and initial temperature and electrical conductivity of the treated media were adjusted, based on calculations made using pertinent fundamental mathematical models. Neither the amount of electric current flowing through the treated product, nor the amount of delivered electric energy or the electric conductivity of the studied media showed any influence on the bactericidal effectiveness of the applied treatments within the studied range.