Pulsed electric field processing of high acid liquid foods: A review

Abstract

Publisher Summary Pulsed electric field (PEF) is a nonthermal food preservation method using high voltage electric field to kill spoilage microorganisms in foods. PEF treatment maintains flavor, color, taste and nutritional value of foods while destroying microorganisms. PEF is useful in processing liquid foods where the food can flow between two electrodes. The generation of PEF processing requires a pulsed power supply, a series of treatment chambers and a temperature regulating system. Therefore, a PEF system usually consists of a high voltage pulse generator, a treatment chamber and a fluid handling system. To process a product using PEF in a continuous system, the product flows through a series of PEF treatment chambers where it is exposed to the desired electric field strength for a desired amount of time. The pulse generator is capable of converting low voltage electricity into high voltage energy to be stored in capacitors until discharged. Three different shapes of high voltage waveforms can be generated and applied to foods. The three waveforms are square wave, exponential decay and under-damped RCL (resistive capacitive and inductive discharge circuit). High voltage electricity is transferred into the food product in the treatment chambers, which may be designed for either static (batch) or continuous processing.