Application of High Voltage Technology to Food Engineering

Abstract

This paper introduces the findings obtained from the development of pasteurization technologies using high voltage pulse electric field (PEF) technology and atmospheric non-equilibrium plasma technology, as engineering applications of high-voltage technology in the food field. In the pasteurization of liquid foods using PEF, we developed and examined the characteristics of a device that incorporates carbon electrodes to prevent metal elution from the electrodes, a membrane structure to prevent the treatment solution from contacting the high-voltage electrodes, and a cooling system for the treatment solution. Using this device, we achieved low-temperature sterilization of sake yeast and Lactobacillus homohiochii in sake. Additionally, we investigated the sensitivity of microorganisms to PEF, the stress responses induced by PEF, and factors affecting sublethally injured cells. In the pasteurization of solid foods using atmospheric non-equilibrium plasma, we demonstrated that contact with plasma and the humidification of the treatment atmosphere to promote the generation of hydroxyl radicals are crucial for improving microbial inactivation efficiency. Furthermore, analysis of plasma-sterilized pepper indicated the potential for high-quality dried solid foods through plasma pasteurization.