Comparison of the Chlorine Inactivation of Yersinia enterocolitica in Chlorine Demand and Demand-Free Systems

Abstract

Inactivation of Yersinia enterocolitica by chlorine (0.6 to 20 ppm) was investigated in distilled water and in tryptic soy broth (TSB, 0.015%) at different temperatures (4, 20, and 40 degrees C). In distilled water, chlorine inactivation of Y. enterocolitica was enhanced by increasing the temperature from 4 to 20 degrees C, and survival curves were described by a model that assumed first-order kinetics followed by tailing in which the microbial concentration remained constant. The presence of TSB increased chlorine resistance of Y. enterocolitica, and survival curves were concave downward. These survival curves were described by a model based on the Weibull distribution. Chlorine decay in distilled water was independent of temperature and of the initial concentration of available chlorine and was modeled by first-order reaction kinetics. Chlorine decay in TSB was independent of the initial chlorine concentration but depended on the treatment temperature and was modeled by the addition of two first-order decay equations. The increased resistance of Y. enterocolitica to chlorine in TSB was not due only to the chlorine demand by the TSB components. These components protected Y. enterocolitica cells from the antimicrobial effect of chlorine.

Colonisation of lettuce by Listeria Monocytogenes

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Microbial Contamination in Peeled Chestnuts and the Efficacy of Postprocessing Treatments for Microbial Spoilage Management

“…; Vitro et al . ). New technologies, including food irradiation has been reported to achieve greater than a 5‐log reduction of pathogens and other microorganisms (pasteurization treatments), having the potential to greatly improve the microbiological quality and safety of produce (Niemira ).…”

Effect of X‐ray treatments on Escherichia coli O157:H7, Listeria monocytogenes , Shigella flexneri , Salmonella enterica and inherent microbiota on whole mangoes

“…Chlorinated water is widely used to wash and decontaminate produce; however, its effectiveness is limited to 1–2 log CFU reduction for most pathogenic and spoilage bacteria (Virto et al . ). Therefore, the food industry is interested in utilizing new effective sanitation technologies in order to meet consumer demands and produce safer raw fruit and vegetables (Allende et al .…”

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