Effect of spraying on chemical properties and bactericidal efficacy of electrolysed oxidizing water

Abstract

Summary A three‐factor, three‐by‐three‐by‐two‐level factorial designs were used for studying the effects of air pressure, sprayer orifice size and electrostatic charge of a spray gun on pH, oxidation‐reduction potential (ORP), electric conductivity and residual chlorine of electrolysed oxidizing (EO) waters with either low (9 mg L−1) or high concentration (88 mg L−1) of chlorine. Results indicated that a smaller orifice produced higher reduction in ORP and chlorine concentration than larger orifices. Electrostatic charge, in general, did not cause a significant reduction in chlorine concentration. High air pressure spray retained more chlorine and gave a higher ORP than low air pressure. EO water with high initial chlorine concentration achieved at least a 3–4 log10 CFU mL−1 reduction in Listeria monocytogenes populations when sprayed with the spray gun, while spraying with a commercial backpack sprayer or a poly‐tank sprayer eliminated Listeria population (9.4 log10 CFU mL−1 reductions) completely. These results demonstrated that although spraying reduced the chlorine in EO water by 20–97%, application of EO water through spraying has potential for reducing bacteria in food‐processing operations.

Applying the Membrane-Less Electrolyzed Water Spraying for Inactivating Bioaerosols

“…8 nozzle. In Hsu et al (2004) study, the smaller sprayer orifice size produced higher reduction (spraying with orifice size 1.016 mm result in 86% chlorine reduction and 0.508 mm result in 95% chlorine reduction) in chlorine concentration than larger orifices size (1.499 mm result in 81% chlorine reduction) under the same pumping pressure (all under 103 KPa pumping) was found. And the larger droplet size would be generated from the larger orifices size.…”

Inactivation efficiency to Bacillus subtilis and Escherichia coli bacterial aerosols of spraying neutral electrolyzed water

“…The capacity of NEW as an effective microbial sanitizer in food and agricultural industries has been widely tested in previous studies (Monnin, Lee, and Pascall, 2012;Guentzel et al, 2010;Park et al, 2009;Cao et al, 2009;Arevalos-Sánchez et al, 2012;Deza, Araujo, and Garrido, 2003;Huang et al, 2008;Koseki et al, 2001;Koseki, Isobe, and Itoh, 2004). Because NaCl is frequently used as an industrial raw material, the NEW has the advantage of being economic, convenient, and safe for in situ production in the facilities.…”

“…Park et al (2007) reported that approximately 70% of FAC concentration was lost and there was an increase of 1.3 AE 0.11 pH units while delivering hypochlorous acid solution with a dynamic fogger to steel and ceramic surfaces. Hsu et al (2004) demonstrated that a smaller sprayer orifice size produced higher reduction in chlorine concentration than larger orifices size during spray electrolyzed oxidizing water. In the study of Hsu et al (2004), spraying electrolyzed oxidizing water with orifice size 1.016 mm resulted in 86% chlorine reduction, 0.508 mm resulted in 95% chlorine reduction, and 1.499 mm resulted in 81% chlorine reduction, all under 103 kPa air pressure pumping.…”

“…Hsu et al (2004) demonstrated that a smaller sprayer orifice size produced higher reduction in chlorine concentration than larger orifices size during spray electrolyzed oxidizing water. In the study of Hsu et al (2004), spraying electrolyzed oxidizing water with orifice size 1.016 mm resulted in 86% chlorine reduction, 0.508 mm resulted in 95% chlorine reduction, and 1.499 mm resulted in 81% chlorine reduction, all under 103 kPa air pressure pumping. In our study, the lower inactivation efficiency while using the smaller no.…”

“…Electrolyzed water is generated by electrolysis of saline brine in a cell within anodic and cathodic electrodes with or without ion-selective permeating membrane. The electrolyzed water contains high oxidation-reduction potential (ORP) and free available chlorine (FAC) compounds (hypochlorous acid HOCl, chlorine gas Cl 2 , and hypochlorite ion OCl À ), resulting in strong antimicrobial activity (Huang et al, 2008). Studies on disinfecting mechanisms found that electrolyzed water performs dehydrogenase activities on E. coli and S. aureus to inactivate their viability.…”