In the following design, a pulsating high voltage output is generated instead of a continuous output, so power consumption is limited. The energy is first transferred to a capacitor, where it builds up over time as if we are slowly filling a bucket. When the bucket is full enough, we suddenly empty it, in a very short time, into the output. So with limited power (low voltage and low current), we are able to build up enough energy to generate a high voltage spike of tens of kilovolts. After the bucket is emptied, it is slowly filled again and the process repeats itself.
In case of PEF treatment of liquid food, the required design parameters of the pulse power generator are highly correlated with the geometry of treatment chamber and the flow rate of the sample food in the treatment chamber.
The circuit proposed by Mohammad Soroosh can't be acceptable for PEF treatment due to large pulse width.