Eradication of Enterobaracter aerogenes, Escherichia coli, Listeria monocytogene, Staphylococcus aurous, and Acetobacter by High Voltage Pulsed Electric Field in Water and Milk Samples

ABSTRACT: Ensuring food and water safety has always been a health challenge globally. The present papers underscores HV-PEF (High Voltage Pulsed Electric Field), a novel approach to eliminate five kinds of microbes prevalent in milk and water in fractions of a second. These microorganisms are Enterobaracter aerogenes, Escherichia coli, Listeria monocytogene, Staphylococcus aurous, and Acetobacter. Objective was to find out the impact of HV-PEF on survival of selected species of bacteria, which are often considered as a concern for water and milk safety. A laboratory experimental setup was designed for producing HV-PEF, which was applied on sample of water and milk. The water sample was obtained from tap, and the milk sample was obtained from Bubalus bubalis. The microbial count was measured by plate method for both samples pre and post exposure to the HV-PEF. The effect was measured with combinations of varying field intensity and number of pulses, the intensity of the field having the highest value of 180 kV/cm (kilovolt-per-centimeter), and the pulse count varied between one to one hundred. Results showed, the endurance of few species was extremely low, at 40 kV filed intensity and 40 pulses. Other microbes also demonstrated low survival ratio (SR) at more than 40kV with pulses-count above 40. Complete inactivation of E. coli was achieved at around 80kV. The inactivation of microbe by HV-PEF varies with morphology and shape of the microorganisms. The annihilation of microorganisms is due to the rupturing of cell wall of microbe by the effect of HV-PEF, instead of ohmic heating (resistance induced).