Efficacy of neutral electrolyzed water to inactivate Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus on plastic and wooden kitchen cutting boards

This study evaluated the efficacy of neutral electrolyzed water (NEW; 64.1 mg/liter of active chlorine) to reduce populations of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Listeria monocytogenes on plastic and wooden kitchen cutting boards. Its effectiveness was compared with that of a sodium hypochlorite solution (NaClO; 62.3 mg/ liter of active chlorine). Inoculated portions of cutting boards were rinsed in either NEW or NaClO solutions, or deionized water (control). Plastic boards were rinsed for I min and wooden boards for I and 5 min. After each treatment, the surviving population of each strain was determined on the surface and in the soaking water. No significant difference (P >= 0.05) was found between the final populations of each strain with regard to the treatment solutions (NEW or NaClO). However, a significant difference (P <= 0.05) was revealed between surface materials after I min of washing. Whereas in plastic boards the initial bacterial populations were reduced by 5 log CFU/50 cm(2), in wooden cutting boards they underwent a reduction of < 3 log CFU/50 cm(2). A 5-min exposure time yielded reductions of about 4 log CFU/50 cm(2). The surviving populations of all bacteria in NEW and NaClO washing solutions were < 1 log CFU/ml after soaking both surfaces. This study revealed that NEW treatment is an effective method for reducing microbial contamination on plastic and wooden cutting boards. NEW efficacy was comparable to that of NaClO, with the advantage of having a larger storage time.