Chapter 1 - Fundamentals of High-Intensity Pulsed Electric Fields (PEF)

Abstract

This chapter reviews the key aspects of pulsed electric field (PEF) technology as a suitable means to pasteurize food products, and finds it a significant innovation that may be implemented in the near future for the purpose of food preservation. It involves the application of a short burst of high voltage to a food placed between two electrodes, which destroys the bacterial cell membrane by mechanical effects with no significant heating of the food. PEF technology has the potential to economically and efficiently improve energy usage, as well as provide consumers with microbiologically safe, minimally processed, nutritious, and fresh-like foods. This chapter discusses the action mechanisms of the technology by describing the important components of the PEF system and how the energy from a high-voltage power supply is stored in a capacitor and discharged through a food material contained, or flowing through a treatment chamber. A technical drawback in PEF processing—of particular relevance—is the dielectric breakdown of foods, which is characterized by a spark and evolution of gas bubbles. This makes the technology unsuitable for the pasteurization of liquid foods containing particles.