Development of a Pilot-scale Pulse Electric Field system for Processing Liquid Foods

Abstract

Pulse-Electric Field (PEF) System can be described as a system that utilises high voltages applied at a specific interval and with a particular wave shape in treatment (inactivation and destruction of micro-organism cells) of liquid or solid food. Pulse-Electric Field food processing system reduces the drawbacks (such as deterioration in sensory values, energy contents, and freshness) of other methods significantly. To generate the high voltage needed for the treatment, a series of capacitors and diodes connected were used. Generation of the desired pulse shape, which is the square wave is achieved through ATmega-328 microcontroller. The pulse control system is made up of a button to vary the treatment time, the power switch and a 16x2 alphanumeric Liquid Crystal Display (LCD) which serves as visual feedback. For the evaluation of the fabricated system, bacteria were cultured using MacConkey agar solution and then diluted in orange juice which serves as samples of liquid food. From the samples prepared, the bacteria count is in order of 1.61x10 5 CFU/mL before treatment, after treatment the count reduced to 1.01 x10 5 CFU/mL and 2.10 x10 4 CFU/mL concerning 1kHz and 2kHz pulse frequency used for the two samples treated.