Pulsed electric fields for food industry: Historical overview

Abstract

The current chapter gives an historical overview on the research works and applications of electricity and specifically pulsed electric fields in food processing. The practical applications of the continuous (DC) or alternating (AC) electric currents for heating of the foods and for killing of microbes in liquid foods have more than one hundred years history. The initial efforts had shown promising possibilities of application of electricity (electrical discharges, rapidly oscillating currents, DC and AC currents) for cooking, ohmic heating, canning, stimulation or killing of bacteria, and sterilization. In the middle of twentieth century the pulsed electric field (PEF) assisted processing of food has also attracted research interests. This interest was warmed up by discovery the phenomenon of electroporation in 1950s-1960s. Practically at the same time the different groups in Germany, Ukraine, and Moldova started their activity on AC/DC and PEF-assisted processing of food products. Two to three decades ago, applications of pulsed electric fields (PEF) for treatment of liquid and solid foods became more and more popular. Many important effects and mechanisms related with impact of PEF on bio, food, or agricultural products were discovered and elucidated for this period. At the same time concept of electroporation was continuously developing. The positive effects of PEE-assisted processing for inactivation of microorganisms, extraction, pressing, osmotic dehydration, drying, and freezing were observed. The final section in chapter covers a brief discussion on the recent advances with special emphasis on the producers of food-oriented commercial PEF-treatment apparatuses with different characteristics, power, and particular protocols.