Development of Nonthermal Sterilization Treatment System without Impacting to Enzyme in Vegetable Drink by Pulsed Electric Field

For the sterilization of food, heat sterilization, chemical sterilization, and similar methods are available. However, they cause the change of the quality and flavor of the food. As the solution, the intense pulsed high electric field (IPEF) sterilization method has been studied. IPEF sterilization is used for the nonthermal sterilization of the foods because it destroys the cell membrane of bacteria physically. In this study, we have attempted to apply the IPEF sterilization for green juice. The development of a circulation sterilization system for a practical test was carried out. It was confirmed that enzyme included in the green juice was not deactivated when IPEF was applied. As a result, at applying 20-min pulse electric field in 30 kV/cm and 40 kV/cm, survival ratios of viable bacteria in the green juice were reduced to about 40% and 12%, respectively. Also, deactivation of superoxide dismutase did not occur when the bacteria were sterilized. (C) 2018 Wiley Periodicals, Inc.