Investigation of optimum frequency for non-heating sterilization by high intensity pulsed electric field for long-term preservation of fresh foods

Currently, foods have been mainly sterilized using chemicals, heating and ultraviolet rays. However, these methods have some problems, for example, the change of the taste and constituent, the risk of the residual chemicals and low efficiency. To solve these problems, the sterilization by the pulsed electric field has been proposed. Cells can be written as equivalent circuits by capacitors and resistors. Therefore, when the pulsed electric field is applied to the cells, parts of the cell which the voltage is applied on are different at frequency components of the pulsed electric field. For example, when the low frequency electric field is applied to the cell, the voltage concentrates to the cell membrane. If the cell membrane has over IV of the voltage, breakdown occurs in the cell membrane. Thereby a pore is made on the cell membrane. When the high frequency electric field is applied to the cell, the voltage concentrates to the cytoplasm and the nucleoplsm. In this case, the electric field affects intranuclear inclusion body directly, such as DNA.