Inactivation of microorganisms with pulsed electric fields: Potential for food preservation

High voltage pulsed electric field (PEF) treatment is a potential non-thermal food decontamination technique to replace or partially substitute thermal processes. Microorganisms in foods can be inactivated with pulsed electric fields at ambient or refrigerated temperatures for a short treatment time of less than a second and the fresh-like quality of food is preserved. During the PEF process, lysis of microorganisms is caused by irreversible structural changes in the membrane, leading to pore formation and destruction of the semipermeable barrier of the membrane. There is convincing evidence that the temperature increase brought about by PEF is not the only factor in microbial inactivation. The bactericidal effect of PEF is related to the electric field strength and treatment time, number of pulses and pulse width. Furthermore, the PEF inactivation is a function of the type of microorganism and the microbial growth stage, initial inoculum size, preculture condition, ionic concentration, and conductivity of the suspension fluid.