Effects of pulsed electric fields on cell membranes in real food systems

• Published in: Innovative food science & emerging technologies 2000-06, Vol.1 (2), p.135-149
• Main Authors: Angersbach, Alexander, Heinz, Volker, Knorr, Dietrich
• Format: Article
• Language: English
• Subjects: Cell membrane; Electropermeabilization; Pulsed electric fields
• ISSN: 1466-8564; 1878-5522
• DOI: 10.1016/S1466-8564(00)00010-2

High frequency current and voltage measurements were used to determine passive electrical properties, such as the polarization effect at intact membrane interfaces and field-induced electropermeability changes in the cellular materials during direct current pulses. The time sequence of the electropermeabilization at the level of the cell membrane showed a similarity to the breakdown phenomena observed in cell systems (potato, apple and fish tissues, as well as plant cell suspension cultures) when a single pulse with critical or supercritical field amplitude is applied. A slight membrane breakdown phenomenon occurred in the first few microseconds after the initiation of the pulse at a critical electric field strength of 150–200 V/cm. Significant membrane breakdown was observed when the field strength of the electric pulses applied directly on the cell systems was in the range of 400–800 V/cm. At various field intensities, the electrical potential across a cell membrane reached a critical value of approximately 0.7–2.2 V. The initiation of conductive channels across the membrane occurred within nanoseconds during the charging process of the membrane, whereas the formation of a high-conductance membrane due to pore expansion took place within a few microseconds. The application of a single pulse, even with supercritical field amplitude, does not necessarily cause an irreversible membrane rupture. The insulating properties of the cell membrane can be completely recovered within several seconds after the termination of the pulse. The biological and engineering aspects of the membrane permeabilization are discussed in this paper. These data are utilized as the basis for the design and optimization of high-intensity pulsed electric field applications in the areas of food science and biotechnology.