Design and optimization of pulsed electric field sterilization system for high flow rate applications

Pulsed electric field (PEF) sterilization is a new non-thermal sterilization technology with high sterilization efficiency, gentle treatment and wide application prospects. However, the exiting pulsed electric field sterilization device has some drawbacks, such as lower processing capacity and weak continuous processing capability, which impede its industrial application progress. In this paper, therefore, multiple groups of co-field type PEF processors were connected in series to treat the bacterial suspensions inoculated with S. aureus and E. coli at an experimental flow rate of 60L/h to obtain sterilization kinetic characteristics. It was discussed that the influence of the initial concentration of bacteria on the sterilization effect. The results shown that, at a flow rate of 60L/h, the PEF system can achieve ideal sterilization effect of 99.99% for both bacteria. With the initial concentration of bacteria gradually decreases, the sterilization efficiency decreases slightly, but remains above 99%. On the basis of this, the freshly squeezed grapefruit juice was further treated to obtain the sterilization effect and quality change law. The grapefruit juice after treated with PEF met the relevant national standards in microorganisms and nutrients. The results are helpful to improve the performance of the PEF system and lay foundation for its applications.