|TAN, JING - National Taiwan Ocean University|
|Hwang, Cheng An|
|HSIAO, HSIN I - National Taiwan Ocean University|
Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2021
Publication Date: 10/3/2021
Citation: Tan, J.N., Hwang, C., Huang, L., Wu, V.C., Hsiao, H. 2021. A pilot-scale evaluation of using gaseous chlorine dioxide for decontamination of foodborne pathogens on produce and low-moisture foods. Journal of Food Safety. http://doi.org/10.1111/jfs.12937.
Interpretive Summary: Produce, nuts, and spices contaminated with foodborne pathogens have been implicated in outbreaks of foodborne illnesses. This study investigated the use of chlorine dioxide gas for microbial decontamination of tomatoes, blueberries, carrots, almonds, and peppercorns. The gas concentrations and treatment times, temperatures, and humidity that effectively reduced the pathogen contamination on these products were identified. The decontamination method can be used by the food processors to reduce the microbial contamination on their products to improve microbial food safety.
Technical Abstract: Small-scale studies have shown that chlorine dioxide gas, ClO2(g), was effective for decontamination of produce, nuts, and spices. This study conducted a pilot-scale evaluation to identify effective ClO2(g) treatment parameters for commercial-scale applications. The gas was produced by a generator utilizing chlorite and chlorine gas for decontamination of Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, and Salmonella inoculated on tomatoes, blueberries, baby-cut carrots, almonds, and peppercorns. Inoculated samples and 45 kg tomatoes in a 1246-L treatment chamber were exposed to ClO2(g) at 70-95% RH to determine the treatment effects on the pathogen reductions. Results showed that ClO2(g) caused higher reductions on produce. The treatment of 1 mg/L-3 h at 70% RH reduced 4.9-6.8, 5.1-5.6, and 4.2-6.3 log CFU/g of STEC, L. monocytogenes, and Salmonella, respectively, on produce, with the highest reductions on baby-cut carrots. For almonds and peppercorns, ClO2(g) treatments under higher RH caused higher reductions. The treatment of 2 mg/L-9 h or 3 mg/L-4 h at 95% RH reduced >4.0 log of STEC and Salmonella on almonds, and 1 mg/L-5 h at 85% RH achieved >5.0 log reductions on peppercorns. Applying moisture to the surfaces of almonds caused >4.0 log reductions using 1 mg/L ClO2(g) for 5 h at 95% RH. This study identified ClO2(g) treatment parameters for achieving >4.0-log reductions of common pathogens and showed ClO2(g) generator is suitable for large-scale decontamination. These findings can be used for pilot-scale ClO2(g) decontamination of these products and for testing using ClO2(g) for commercial-scale decontamination trials.