title: Enhanced bactericidal action of acidified sodium chlorite caused by the saturation of reactants.
abstract: OBJECTIVE
  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.
  
  
  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 (Cl(2) and ClO(2)) yields than the other procedures. A 5-min treatment with ASC, produced using the other procedures, resulted in a reduction of < 3·5 log CFU ml(-1) (Gram positive = 0·18-0·78; Gram negative = 0·03-3·49 log CFU ml(-1)), whereas ASC produced with the DAR procedure using the saturated reactants completely inactivated all of the test pathogens within 5 min without recovery (initial concentration = 6·94-7·08 log CFU ml(-1)).
  
  
  CONCLUSIONS
  The ASC production with the DAR procedure using the saturated reactants maximizes both the antimicrobial compound yields and bactericidal effects of the ASC solutions.
  
  
  CONCLUSIONS
  This study will contribute to increase the efficiency of ASC treatments for disinfections reducing the effective SC concentrations for industrial use.
authors.affiliation: Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
authors.forename: N H
authors.initials: NH
authors.lastname: Kim
authors.forename: T H
authors.initials: TH
authors.lastname: Park
authors.forename: M S
authors.initials: MS
authors.lastname: Rhee
mesh_terms: D002712:Chlorides / Q000737:chemistry / Q000494:pharmacology*; D019343:Citric Acid / Q000737:chemistry; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D019453:Escherichia coli O157 / Q000187:drug effects; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D008089:Listeria monocytogenes / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D002712:Chlorides; D004202:Disinfectants; D019343:Citric Acid; C001599:chlorite
keywords: acidified sodium chlorite; bactericidal action; foodborne pathogen; initial concentration of reactants; preparation procedure