Feasibility and efficacy of using gaseous chlorine dioxide generated by sodium chlorite-acid reaction for pilot-scale decontamination of foodborne pathogens on produce

Authors: CHAI, HUI ERH - National Taiwan University; Hwang, Cheng An; Huang, Lihan; Wu, Vivian; SHEEN, LEE YAN - National Taiwan University

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2019
Publication Date: 8/22/2019
Citation: Chai, H., Hwang, C., Huang, L., Wu, V.C., Sheen, L. 2019. Feasibility and efficacy of using gaseous chlorine dioxide generated by sodium chlorite-acid reaction for pilot-scale decontamination of foodborne pathogens on produce. Food Control. 108:106839. https://doi.org/10.1016/j.foodcont.2019.106839.
DOI: https://doi.org/10.1016/j.foodcont.2019.106839

Interpretive Summary: Chlorine dioxide (ClO2) gas is a potent disinfectant and its use reduces water usage and waste water comparing to aquesous disinfectants. This study evaluated two ClO2 gas generation methods for decontamination of foodborne pathogens on tomatoes, blueberries, and baby-cut carrots. Both methods are feasible for pilot-scale generation of ClO2 gas for decontamination of produce. Cumulative ClO2 exposures of 300, 1300, and 1600 ppm-h achieved >4.0 log CFU/g reductions of pathogenic Escherichia coli, Salmonella, and L. monocytogenes. Results from this study can be used for decontamination of tomatoes, blueberries, and baby-cut carrots at scale similar to this study or for evaluating ClO2 decontamination applications in commercial-scale trials.

Technical Abstract: The objective of this study was to evaluate the feasibility and efficacy of using chlorine dioxide (ClO2) gas generated by dry media (sodium chlorite and ferric chloride) and sodium chlorite-hydrogen chloride dosing methods for decontamination of foodborne pathogens on produce. Tomatoes, blueberries, and baby-cut carrots inoculated with Shiga toxin-producing Escherichia coli (STEC), Salmonella, and Listeria monocytogenes were treated with ClO2 gas in a decontamination process. The effects of cumulative ClO2 exposure, or ClO2 concentrations (ppm) × treatment time (h) (ppm-h), on the reduction of inoculated pathogens were determined. The increase of cumulative ClO2 exposure between 300-1900 ppm-h increased the log reductions of pathogens on produce, whereas no significant increase in log reductions was observed after 1900 ppm-h. The Cumulative ClO2 exposures of 300, 1300, and 1600 ppm-h caused >4.0-log CFU/g reductions of the pathogens on baby-cut carrots, tomatoes, and blueberries, respectively. The treatment was most effective against the pathogens on baby-cut carrots, likely due to the moisture on the surface of the peeled carrots. This study showed that both ClO2 generation methods are suitable and effective for decontamination of produce. The correlation between the cumulative ppm-h and pathogen reduction was independent of the quantity of products and other factors that may affected the consumption rate of ClO2. Therefore, the treatment parameters obtained from this study can be used for similar scales of decontamination applications or as references for evaluating using ClO2 gas for decontamination of tomatoes, blueberries, and baby-cut carrots in commercial-scale trials.