Impact of low-concentrated acidic electrolysed water obtained by membrane electrolysis on the decontamination of meat microbiota

The influence of acidic electrolysed water (AEW) treatment on inactivation of pure bacterial cultures inoculated onto the surface of agarised media and surface microbiota of pork meat were examined. Low-concentrated AEW (low concentration of sodium chloride and low current electrolysis) was generated by electrolysis (5 or 10 min) of 0.001% or 0.01% NaCl solution. The number of viable microorganisms was determined using a plate count method. The effect of AEW on bacterial cell morphology were investigated using scanning electron microscopy (SEM). After treatment with AEW, a significant, about 3.00 log reduction of Pseudomonas fluorescens, Yersinia enterocolitica, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, and Micrococcus luteus populations was observed. In the AEW treatment of pork, the highest reduction of total number of microorganisms (2.1 log reduction), yeast and moulds (2.5-2.6 log reduction), and psychrotrophs (more than 1 log reduction) was observed after spraying with 0.001% NaCl subjected to 10 min electrolysis. SEM revealed disruption and lysis of E. coli and S. aureus cells treated with AEW, suggesting a bactericidal effect. Higher available chlorine concentration (0.37-8.45 mg/L), redox potential (863.1-1049.8 mV), and lower pH (2.73-3.70) had an influence on the shape of bacteria and the number of breaks in the bacterial membrane.