Effectiveness of low concentration electrolyzed water to inactivate foodborne pathogens under different environmental conditions.
Strong acid electrolyzed water (SAEW) has a very limited application due to its low pH value (<2.7) and corrosive characteristics. Thus, we developed new low concentration electrolyzed water (LcEW). The efficacy of LcEW under various treatment conditions for the inactivation of different foodborne pathogens in pure culture was evaluated and compared with SAEW. The efficiency of LcEW and SAEW for the inactivation of predominant foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Salmonella Typhimurium) with different dipping times (1, 3, 5, 7 and 10 min), pH values (2.5, 4.0, 5.0, 6.0 and 9.0) and temperatures (4, 15, 23, 35 and 50 degrees C) were determined. Reductions of bacterial populations of 1.7 to 6.6 log(10) CFU/mL in various treated conditions in cell suspensions were observed after treatment with LcEW and SAEW, compared to the untreated control. Dip washing (1 min at 35 degrees C) of lettuce leaves in both electrolyzed water resulted in 2.5 to 4.0 log(10) CFU/g compared to the unwashed control. Strong inactivation effects were observed in LcEW, and no significant difference (p>0.05) was observed between LcEW and SAEW. The effective form of chlorine compounds in LcEW was almost exclusively hypochlorous acid (HOCl), which has strong antimicrobial activity and leaves no residuals due to the low concentration of residual chlorine. Thus, LcEW could be widely applied as a new sanitizer in the food industry.
Rahman
S M E
SM
Department of Food Science and Biotechnology and Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Gangwon 200-701, Republic of Korea.
Ding
Tian
T
Oh
Deog-Hwan
DH
D001419:Bacteria / Q000187:drug effects*; D017606:Chlorine Compounds / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology*; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D018545:Lactuca / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors
D017606:Chlorine Compounds; D004202:Disinfectants; C118085:superoxidized water; D006861:Hydrogen Peroxide