Treatment of Escherichia coli O157:H7 with lactic acid, neutralized electrolyzed oxidizing water and chlorine dioxide followed by growth under sub-optimal conditions of temperature, pH and modified atmosphere

• Published in: Food microbiology 2009-09, Vol.26 (6), p.629-637
• Main Authors: Smigic, Nada, Rajkovic, Andreja, Antal, Eszter, Medic, Helga, Lipnicka, Barbara, Uyttendaele, Mieke, Devlieghere, Frank
• Format: Article
• Language: English
• Subjects: aerobic conditions; air; bacterial contamination; Biological and medical sciences; carbon dioxide; Carbon Dioxide - metabolism; Chlorine Compounds - pharmacology; Chlorine dioxide; Colony Count, Microbial; Consumer Product Safety; decontamination; electrolytes; Escherichia coli; Escherichia coli O157 - drug effects; Escherichia coli O157 - growth & development; Escherichia coli O157:H7; Food Contamination - prevention & control; Food Handling - methods; Food industries; food industry; Food microbiology; food packaging; Food Packaging - methods; food pathogens; Food Preservation - methods; food storage; fresh-cut foods; Fundamental and applied biological sciences. Psychology; General aspects; Handling, storage, packaging, transport; Hydrogen-Ion Concentration; Lactic acid; Lactic Acid - pharmacology; Modified atmosphere packaging; Neutral electrolyzed oxidizing water; nitrogen; Nitrogen - metabolism; Oxides - pharmacology; oxygen; Oxygen - metabolism; plate count; sanitizing; shelf life; storage temperature; Sub-lethal injury; sublethal effects; Temperature; Water - pharmacology
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2009.04.010

The utilization of sub-lethal decontamination treatments gains more and more interest due to the increased consumers' demand for fresh, minimally processed and convenient food products. These products rely on cold chain and hurdle (combination) technology to provide microbiological safety and quality during their shelf life. To investigate the ability of surviving cells to resuscitate and grow in a food simulating environment, sub-lethal decontamination treatments were coupled with subsequent storage under sub-optimal growth conditions. For this purpose chlorine dioxide (ClO 2) and neutralized electrolyzed oxidizing water (NEW)-treated cultures of Escherichia coli O157:H7 were inoculated in TSB-YE of pH 5.8 and a w 0.99, and stored at 10 °C, 12.5 °C and 15 °C, under four different atmospheres (0%, 30% and 60% CO 2 balanced with N 2, and air). Due to the severity of injury, lactic acid-treated cells were inoculated in TSB-YE pH 7.0. Data obtained reveal that the fraction of sub-lethally injured E. coli O157:H7 undergoes an additional inhibitory effect during the storage period under of sub-optimal conditions. Observed extension in the lag growth phase was a direct consequence prior sub-lethal injury. The effects of liquid ClO 2 and NEW were less pronounced in comparison to lactic acid. The current study signifies the potential utilization of appropriate combination of different extrinsic and intrinsic factors in the elimination or growth inhibition of food-borne pathogens.