Application of Pulsed Electric Field for Milk Pasteurization

Abstract

Abstract

In this study, pasteurization of milk using pulsed electrical field (PEF) was applied and presented. A laboratory-scale milk pasteurization system using pulsed electric field technique was developed and consisted of a DC pulsed high voltage power supply, a treatment chamber and a fluid flow system. Milk was transported from the milk tank into the treatment chamber at a flow rate of 2 L/min. In the chamber, a DC pulsed high voltage was applied to the electrodes of about 30 kV with frequency of about 30 kHz, therefore, the high electric field strength was found 5.53 x 103 kV/m. In this study, the developed system was preliminary tested with a low-fat and sterilized milk mixed with an E.coli. It was found from the preliminary test that the E.coli was reduced from about 3.28 x 105 cells/ml to 1.09 x 104 cells/ml with the residence time of about 30 min. The milk temperature was increased after the chamber of about 2 - 3°C from the room temperature. The energy of the system was equivalent to about 2.73 x 103 J/kg.

Keywords : Liquid Foods; Pasteurization; Pulsed Electric Field; igh Voltage