Summary
Abstract
Raw fish is prone to the risk of microbial outbreaks due to contamination by pathogenic microorganisms, such as Escherichia coli O157:H7 and Listeria monocytogenes. Therefore, it is essential to treat raw fish to inactivate pathogenic microorganisms. Electrolyzed Oxidizing Water (EO) is a novel antimicrobial agent containing acidic solution with a pH of 2.6, Oxidation Reduction Potential (ORP) of 1150 mV, and 70 90 ppm free chlorine, and alkaline solution with a pH of 11.4 and ORP of 795 mV. This study was undertaken to evaluate the efficacy of acidic EO water treatment and alkaline EO water treatment followed by acidic EO water treatment at various temperatures for the inactivation of E. coli O157:H7 and L. monocytogenes Scott A on the muscle and skin surfaces of inoculated salmon fillets. Inoculated salmon fillets were treated with acidic EO water at 22 and 35 C and 90 ppm free-chlorine solution as control at 22 C for 2, 4, 8, 16, 32, and 64 min. The acidic EO water treatments resulted in a reduction of L. monocytogenes Scott A population in the range of 0.40 log10 CFU/g (60%) at 22 C to 1.12 log10 CFU/g (92.3%) at 35 C. Treatment of inoculated salmon fillets with acidic EO water reduced E. coli O157:H7 populations by 0.49 log10 CFU/g (67%) at 22 C and 1.07 log10 CFU/g (91.1%) at 35 C. The maximum reduction with chlorine solution (control) was 1.46 log10 CFU/g (96.3%) for E. coli O157:H7 and 1.3 log10 CFU/g (95.3%) for L. monocytogenes Scott A at 64 min. A response surface model was developed for alkaline treatment followed by acidic EO water treatment to predict treatment times in the range of 5 30 min and temperatures in the range of 22 35 C for effective treatment with alkaline EO water followed by acidic water, alkaline and acidic water treatments. Response surface analysis demonstrated maximum log reductions of 1.33 log10 CFU/g (95.3%) for E. coli O157:H7 and 1.09 log10 CFU/g (91.9%) for L. monocytogenes Scott A. Data collected from the treatments was used to develop empirical models as a function of treatment times and temperature for prediction of population of E. coli O157:H7 and L. monocytogenes Scott A. Correlations (R2) of 0.52 and 0.77 were obtained between model predicted and experimental log10 reduction for E. coli O157:H7 and L. monocytogenes Scott A reductions, respectively. These results clearly indicated that EO water has a potential to be used for decontamination of raw fish.
Study details
- Published in: Journal of Food Engineering 72.3 (2006): 234-241
- Microbes studied: Escherichia coli O157: H7, Listeria monocytogenes
Source
Source: Journal of Food Engineering 72.3 (2006): 234-241
Conditions tested
| Parameter | Value |
|---|---|
| Organisms | Escherichia coli, Listeria monocytogenes |
| Relevant sectors | Food Processing, Seafood |
| Publication | Journal of Food Engineering, 2006 |
Reading this responsibly
Published figures are obtained under controlled conditions, usually on clean surfaces or in defined matrices. Organic load, surface condition, temperature and application coverage all affect real-world performance. Use these numbers to design a protocol, then validate it on your own site with environmental swabbing.
Applying it
Concentrations in this range are within the adjustable output of every EcoloxTech commercial system, so implementing this protocol is a settings question rather than a procurement one. Where the claim needs to sit on a registered label, see HOCl-AS200, EPA Reg. No. 101112-1.