Modeling of electrochemical reactions during pulsed electric field treatment

Abstract

In pulsed electric field (PEF) treatment, a biological material (cell suspension, plant, animal, or human tissue) is placed between two electrodes of a treatment chamber and here exposed to short (from several nanoseconds to several milliseconds) high intense electric field (0.5-80 kV/cm) pulses, with the final aim to induce the physical electropermeabilization of the cell membranes. However, when typical conditions for PEF processing are applied, undesired electrochemical reactions, especially those involving metal release from the electrodes, unavoidably occur at the electrode-electrolyte interface of a PEF treatment chamber. The occurrence of these electrode reactions is a very complex phenomenon, which is affected by several factors, such as PEF chamber design and electrode material, PEF electrical parameters, as well as composition and chemical-physical properties of the treated biological material. In this chapter, the basic concepts of electrochemistry are reported, and a detailed description of the electrochemical phenomena occurring at the electrode-electrolyte interface of a PEF chamber is given with a special emphasis to the case of PEF application for food pasteurization. Finally, particular attention is devoted to metal release from electrodes in a PEF treatment chamber, and a possible methodological approach to develop a mathematical model describing the phenomena of the migration of the electrode material into the treated biomaterial is also presented.