Enhanced bactericidal action of acidified sodium chlorite caused by the saturation of reactants

AIMS: Factors affecting the antibacterial action of acidified sodium chlorite (ASC), a widely used disinfectant, have not been determined. This study investigated the significant factors suggesting efficient production method to maximize bactericidal action of ASC. METHODS AND RESULTS: The effects of (i) preparation procedures (total three methods); (ii) initial concentrations of reactants: sodium chlorite (SC) and citric acid (CTA) (up to maximum solubility of each reactant) and (iii) final pH values (3·0 and 2·5) to the bactericidal action of ASC were investigated with a fixed final concentration of SC (10 ppm) using various foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Staphylococcus aureus). The antimicrobial compounds produced and the bactericidal effects depended on the preparation procedure and the initial concentrations of the reactants. The ASC prepared by premixing highly concentrated reactants (in particular > 40%) followed by dilution (dilution after reaction, DAR) was more effective in inactivating foodborne pathogens, and it produced higher antimicrobial compound (Cl₂and ClO₂) yields than the other procedures. A 5‐min treatment with ASC, produced using the other procedures, resulted in a reduction of