Inactivation of Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus on stainless steel and glass surfaces by neutral electrolysed water.
OBJECTIVE
To ascertain the efficacy of neutral electrolysed water (NEW) in reducing Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes on glass and stainless steel surfaces. Its effectiveness for that purpose is compared with that of a sodium hypochlorite (NaClO) solution with similar pH, oxidation-reduction potential (ORP) and active chlorine content.


RESULTS
First, the bactericidal activity of NEW was evaluated over pure cultures (8.5 log CFU ml-1) of the abovementioned strains: all of them were reduced by more than 7 log CFU ml-1 within 5 min of exposure either to NEW (63 mg l-1 active chlorine) or to NaClO solution (62 mg l-1 active chlorine). Then, stainless steel and glass surfaces were inoculated with the same strains and rinsed for 1 min in either NEW, NaClO solution or deionized water (control). In the first two cases, the populations of all the strains decreased by more than 6 log CFU 50 cm-2. No significant difference (P<or=0.05) was found between the final populations of each strain with regard to the treatment solutions (NEW or NaClO solution) or to the type of surface.


CONCLUSIONS
NEW was revealed to be as effective as NaClO at significantly reducing the presence of pathogenic and spoilage bacteria (in this study, E. coli, L. monocytogenes, P. aeruginosa and S. aureus) on stainless steel and glass surfaces.


CONCLUSIONS
NEW has the advantage of being safer than NaClO and easier to handle. Hence, it represents an advantageous alternative for the disinfection of surfaces in the food industry.
Deza
M A
MA
Institute of Food Research and Analysis, University of Santiago de Compostela, Santiago de Compostela, Spain. madeza@usc.es
Araujo
M
M
Garrido
M J
MJ
D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods; D004572:Electrolysis; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D005898:Glass; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000302:isolation & purification; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D013193:Stainless Steel; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D014867:Water / Q000737:chemistry / Q000494:pharmacology*
D014867:Water; D013193:Stainless Steel