Spraying efficiency of slightly acidic electrolyzed water for reducing foodborne pathogens and natural microflora on shell eggs

Abstract

Abstract. The efficacy of slightly acidic electrolyzed water (SAEW) to inactivate foodborne pathogens and indigenous microbiota on shell eggs were evaluated and compared to that of chlorine dioxide (ClO 2 ) solution. The eggs were artificially inoculated with S.enteritidis, E.coli O157:H7 and S.aureus and sprayed with SAEW, alkaline electrolyzed water (AlEW) followed by SAEW (AlEW+SAEW) and ClO 2 solution at available chlorine concentrations (ACC) of 60, 80 and 100 mg L -1 , respectively, and with alkaline electrolyzed water and deionized water as control. SAEW, AlEW+SAEW, and ClO 2 solution treatments significantly reduced the population of S.enteritidis by 1.52 to 2.36 log 10 CFU g -1 , E.coli O157:H7 by 1.69 to 3.68 log 10 CFU g -1 , and S.aureus by 1.16 to 2.82 log 10 CFU g -1 , respectively relative to control. The effect of SAEW on the natural microbiota of fresh egg shells was also studied. Spraying shell eggs with SAEW and ClO 2 solution at the ACC of 60 mg L -1 had no significant bactericidal difference for foodborne pathogens and indigenous microbiota on shell eggs, whereas the bactericidal activity of SAEW for E.coli O157:H7, S.aureus, total aerobic bacteria and moulds and yeasts was significantly higher than that of ClO 2 solution at ACCs of 80 and 100 mg L -1 . Microbial counts decreased with the increasing SAEW concentrations, SAEW was found to be more effective when used in conjunction with AIEW. Results indicate that the disinfectant efficacy of SAEW is equivalent to or higher than that of ClO 2 solution, and therefore SAEW shows the potential to be used for sanitization of egg shells as an environmentally friendly disinfection agent.