Pulsed Electric Fields PEF

High temperatures also increase the electrical conductivity of the product, lowering the maximnm electric field strength viable in the treatment chamber before undergoing a dielectric breakdown of the system, evidenced by an electric spark. In addition, air bubbles or suspended particles may also produce dielectric breakdown (Wouters et al., 2001a Gongora-Nieto et al., 2002, 2003). 

Several pilot plant-scale PEF systems have been developed and a great number of bench-scale eqnipment is spread aronnd the world in different research groups. The use of 

---

In the interdisciplinary field of biophysics and biotechnology, the bioeffects of electric field have received considerable interest for both fundamental studies on these interaction mechanisms and potential application. However, the effects of pulsed electric field (PEF) on secondary metabolism in plant cell cultures and fermentation processes have been unknown. Therefore, it would be very interesting to find out whether PEF could be used as a new tool for stimulating secondary metabolism in plant cell cultures for potential application to the value-added plant-specific secondary metabolite production. Furthermore, if the PEF permeabilization and elicitation are discovered in a cell culture system, the combination of... 

Non-thermal processes other than ionizing irradiation are processes such as ultrasound, high hydrostatic pressure (HHP) and pulsed electric fields (PEFs) (Raso and Barbosa-Canovas, 2003 Ross el al., 2003). 

High hydrostatic pressure (HHP) and pulsed electric fields (PEFs) are rather novel technologies where relatively little research has been carried out. These methods have mostly been tested in combination with other decontamination methods and also mostly on either microorganisms in vitro or on foods of animal origin (e.g. milk, eggs and meat) (Raso and Barbosa-Canovas, 2003 Ross et al., 2003). More research is needed in order to find out if such methods are applicable to the fresh produce industry. 

In order to avoid chemical compounds at all, it is also possible to apply a high voltage to kill microbes on surfaces. It was found that a direct current kills E. coli cells, probably by heat or by hydrogen peroxide formation [84], Microbial cells can be effectively killed by using pulsed electric fields (PEF), probably by frequently disturbing the cell membrane potential [85], PEF that was found to lower microbial cell numbers in food and drinks was also shown to effectively kill E. coli and Listeria innocua cells attached to polystyrene beads [86], This demonstrates the potential of applying this purely physical method to surfaces as well. 

Fleischman, G.J., Ravishankar, S., and Balasubramaniam, V.M. 2004. The inactivation of Listeria monocytogenes by pulsed electric field (PEF) treatment in static chamber. Food Microbiology 21 91-95. 

Cell disruption methods can be roughly divided into two categories mechanical ones, e.g., bead mill, homogenizers, and ultrasound and nonmechanicals like organic solvents, osmotic shock, supersonic fluid feed (SFF) and pulsed electric field (PEF). For extracting microalgal components, several methods were applied (Table 2.6). 

Zbinden MDA, Sturm BSM, Nord RD, Carey WJ, Moore D, Shinogle H, et al. Pulsed electric field (PEF) as an intensification pretreatment for greener solvent lipid extraction from microalgae. Biotechnol Bioeng 2013 110 1065. 

Pulsed electric field (PEF) employs a high-energy pulsed electric field, usually 2-80 kV/cm, on a material between two electrodes. When PEF is applied, membrane semipermeability decreases, cells break... 

The application of an external pulsed electric field (PEF), the induced local structural changes of the cell membrane, and also the increase in permeability due to the appearance of permanent membrane pores were found to positively affect any subsequent drying processes of porous plant materials. PEF provides an alternative to the mechanical, thermal or enzymatic cell disintegration of plant tissue, providing a short-term (milliseconds), low-energy pretreatment (<10kJkg-Y... 

Pulsed Electric Field (PEF) Application as a Pretreatment 121S... 

---