Effect of slightly acidic electrolyzed water for inactivating Escherichia coli O157:H7 and Staphylococcus aureus analyzed by transmission electron microscopy

J Food Prot. 2010 Dec;73(12):2211-6. doi: 10.4315/0362-028x-73.12.2211.

Abstract

The use of different available chlorine concentrations (ACCs) of slightly acidic electrolyzed water (SAEW; 0.5 to 30 mg/liter), different treatment times, and different temperatures for inactivating Escherichia coli O157:H7 and Staphylococcus aureus was evaluated. The morphology of both pathogens also was analyzed with transmission electron microscopy. A 3-min treatment with SAEW (pH 6.0 to 6.5) at ACCs of 2 mg/liter for E. coli O157:H7 and 8 mg/liter for S. aureus resulted in 100% inactivation of two cultures (7.92- to 8.75-log reduction) at 25°C. The bactericidal activity of SAEW was independent of the treatment time and temperature at a higher ACC (P > 0.05). E. coli O157:H7 was much more sensitive than S. aureus to SAEW. The morphological damage to E. coli O157:H7 cells by SAEW was significantly greater than that to S. aureus cells. At an ACC as high as 30 mg/liter, E. coli O157:H7 cells were damaged, but S. aureus cells retained their structure and no cell wall damage or shrinkage was observed. SAEW with a near neutral pH may be a promising disinfectant for inactivation of foodborne pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Consumer Product Safety
  • Disinfectants / pharmacology*
  • Dose-Response Relationship, Drug
  • Escherichia coli O157 / drug effects*
  • Escherichia coli O157 / ultrastructure
  • Food Contamination / analysis
  • Food Contamination / prevention & control
  • Hydrogen Peroxide / pharmacology*
  • Microscopy, Electron, Transmission
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / ultrastructure
  • Temperature
  • Time Factors

Substances

  • Disinfectants
  • superoxidized water
  • Hydrogen Peroxide