Effect of Electrolyzed Water for Reduction of Foodborne Pathogens on Lettuce and Spinach

• Published in: Journal of food science 2008-08, Vol.73 (6), p.M268-M272
• Main Authors: Park, E.-J, Alexander, E, Taylor, G.A, Costa, R, Kang, D.-H
• Format: Article
• Language: English
• Subjects: acidity; alkalinity; bacterial contamination; Biological and medical sciences; Colony Count, Microbial; Consumer Product Safety; deionized water; detection limit; disinfection; Disinfection - methods; E coli; Electrolysis; electrolyzed water; Escherichia coli; Escherichia coli O157 - growth & development; Escherichia coli O157:H7; food contamination; Food industries; Food Microbiology; food pathogens; Food science; foodborne illness; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Humans; Hydrogen-Ion Concentration; Lactuca - microbiology; Lettuce; Listeria monocytogenes; Listeria monocytogenes - growth & development; Oxidation-Reduction; plate count; Salmonella; Salmonella typhimurium; Salmonella typhimurium - growth & development; spinach; Spinacia oleracea; Spinacia oleracea - microbiology; Time Factors; Water; water treatment
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2008.00809.x

The ability of electrolyzed water (EW) to inactivate foodborne pathogens on the surfaces of lettuce and spinach was investigated. Lettuce and spinach leaves were inoculated with a cocktail of 3 strains each of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and treated with acidic electrolyzed water (AC-EW), alkaline electrolyzed water (AK-EW), alkaline electrolyzed water followed by acidic electrolyzed water (sequential treatment, AK-EW + AC-EW), deionized water followed by acidic electrolyzed water (sequential treatment, DW + AC-EW), and deionized water (control, DW) for 15, 30 s, and 1, 3, and 5 min at room temperature (22 ± 2 °C). For all 3 pathogens, the same pattern of microbial reduction on lettuce and spinach were apparent. The relative efficacy of reduction was AC-EW > DW + AC-EW [almost equal to] AK-EW + AC-EW > AK-EW > control. After a 3-min treatment of AC-EW, the 3 tested pathogens were reduced below the detection limit (0.7 log). DW + AC-EW and AK-EW + AC-EW produced the same levels of reduction after 5 min when compared to the control. AK-EW did not reduce levels of pathogens even after a 5-min treatment on lettuce and spinach. Results suggest that AC-EW treatment was able to significantly reduce populations of the 3 tested pathogens from the surfaces of lettuce and spinach with increasing time of exposure.