Purpose: The purpose of this study was to develop a portable and affordable sanitizing unit that can effectively control foodborne pathogens including Escherichia coli O157:H7 and Listeria monocytogenes.
Methods: Oxidation–reduction potential (ORP) and pH of generated electrolyzed water were assayed by meters. Free available chlorine (FAC) was determined by a liquid kit. Partial catholyte solution was reintroduced to electrolysis for modifying the output electrolysis water to be pH neutral. A mathematical modeling was proposed to describe the input-output and optimization of the FAC production of this electrolysis system. Sanitizing effects of generated sanitizers from this unit on E. coli O157:H7 C7927 and L. monocytogenes BAA-839 were compared with electrolyzed water generated from a commercial large unit.
Results: A RuO2-IrO2/TiO2 PTFE electrode with dimension 10 cm × 5 cm × 1 cm was found very effective. Optimization equations were generated for FRC, pH and ORP, respectively. For a starting concentration of 8.29 ± 0.07 log CFU/ml of E. coli O157:H7, 4 mg/L of the two solutions generated from developed unit and a commercial large unit resulted in 5.70 ± 0.09 and 5.75 ± 0.23 log CFU/ml, respectively. Similar results were found for L. monocytogenes. The developed sanitizer was pH neutral (7.08 ± 0.08) compared to the commercial one (3.77 ± 0.18). Moreover, the developed sanitizer had similar sanitizing effect on both E. coli O157:H7 and L. monocytogenes commercial sanitizer generated from large unit. At 40 mg/L, both sanitizers achieved ≥6 log CFU reductions (P>0.05).
Significance: The results suggest that the developed prototype unit is promising as a sanitizing unit for consumers to control foodborne pathogens.