Bactericidal efficiency of electrolyzed oxidizing water for salmonella pullorum and contaminated eggs

Salmonella related to poultry products is the main potential source of human Salmonella infection. The risk of a salmonellosis outbreak from consuming contaminated eggs is a societal and governmental concern. The bactericidal efficiency of electrolyzed oxidizing (EO) water for inactivating Salmonella pullorum (S. pullorum) and artificially inoculated shell eggs were examined in this study. The effects of available chlorine concentrations (0.1-2.0 mg/l) and pH values (2.5, 3.5, 4.6. 5.7 and 6.5) on the bactericidal activity ofEO water were evaluated by using pure cultures (7.60 logio cju/ml) ofS. pullorum strains. The bactericidal activity increased with increasing available chlorine concentration and with decreasing pH value of EO water. The bacteria were completely inactivated when the available chlorine concentration of EO water was higher than 1.0 mg/l. At a sufficient available chlorine concentration (greater than 3.0 mg/l), the complete inactivation ofS. pullorum can be achieved with pH values ranging from 2.5 to 6.5. For the in vitro experiments, shell eggs were sterilized with four different treatments, spraying EO water, soaked in EO water, soaked in alkaline electrolyzed water followed by soaked in EO water (combination), and soaked in NaCIO solution, respectively. Treated eggs showed a reduction in bacterial population greater than 3.6 logl0 cfu/ml. The four treatments resulted in 100% inactivation ofS. pullorum on the surface of shell egg samples at an available chlorine concentration of 5 mg/l. Results indicated that EO water may be a promising disinfectant agent for the shell egg washing process without environmental pollution.