Minimum intensity of pulsed electric field for deactivation of Staphylococcus aureus, Salmonella sp. and Escherichia coli bacteria

Electric fields with high-intensity pulses can cause cell death in human organs. This study aimed to investigate the minimum intensity of pulsed electric fields that can still be used for bacterial deactivation, bacterial size effects on cell membrane permeability thresholds and effects of treatment to electric fields on protein and fat content. The study was conducted on a laboratory scale with samples of Staphylococcus aureus, Salmonella sp. and Escherichia coli bacteria grown in milk. The results showed that Escherichia coli bacteria needed an electric field with a minimum intensity of 3.5 kV/cm, while Staphylococcus aureus and Salmonella sp. required a minimum intensity of 4.0 kV/cm with a treatment time of about 25 minutes. The finding in this study was that larger size bacteria have a lower permeability threshold than small bacteria. The treatment by electric fields with minimum intensity did not reduce the protein content but decreased the fat content in milk. Decreased protein and fat content in milk was influenced by the intensity of the electric field used. The treatment of using pulsed electric fields has the potential to be used to process food products into low-fat foods