Electric field Analysis of Water Electrodes for Noninvasive Pulsed Electric field Applications

Abstract

Electroporation is an effective phenomenon of inactivating viable pathogens present in the liquid food for pulsed electric field (PEF) applications. It is a technique which depends on applied electric field strength for causing pores on cell plasma membrane. The various parameters which affect the electroporation efficacy are, the electric field intensity, pulse width, number of pulses, pulse interval and the electrode. The electrode provides a contact between the high voltage pulse generator and the liquid food, and it plays an important role in getting the required inactivation outcome. The electric field distribution varies based on electrode designs. Parallel plate electrodes are generally used due to the uniform electric field it delivers in the inactivation area, where high possibility of microbial inactivation will occur. This paper analyses the effectiveness of round edged parallel plate electrodes immersed in water which provides uniform electric field distribution in the inactivation area. Analyses have been performed on electric field distribution through four kinds of materials such as glass, alumina, quartz and plexiglass, which contains these electrodes in the center filled with sterile water. The electrodes are circular, and edge smoothened and hence the field distribution is also analyzed on electrode edges. The distance between the electrodes including the surface material is kept at 5 mm. The diameter of the electrodes are 40 mm and the electric field simulations are implemented in ANSYS MAXWELL v 15.0. Based on results it is reported that alumina required less peak voltage for generating 20 kV/cm field strength (nominal field required for bacterial inactivation) when compared with other materials. Also alumina exhibited less reduction of field travelling through it, and resulted in 82% of field application in the inactivation area which is comparatively higher than other materials. The results indicate that alumina is highly recommended for future noninvasive pulsed electric field applications.