Microbicidal effectiveness of irradiation from Gamma and X-ray sources at different dose rates against the foodborne illness pathogens Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes in rice. (October 2020)

• Record Type: Journal Article
• Authors: Begum, Tofa; Follett, Peter A.; Hossain, Farah; Christopher, Larry; Salmieri, Stephane; Lacroix, Monique
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 132(2020)
• Publication Date: 2020-10
• Subjects: Microbial control -- Irradiation -- Dose rate -- Essential oil -- Radiosensitization; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2020.109841
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The radiation response of three foodborne illness pathogens was examined for irradiation with cobalt-60 Gamma and low-energy (125 keV) X-ray at different dose rates. Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes were inoculated into rice and irradiated at target doses of 0 (control), 250, 500, 750, 1000, and 1500 Gy with either Gamma radiation (dose rates of 9.1, 3.9 or 0.22 kGy/h) or X-ray radiation (dose rate of 0.76 kGy/h). Doses were measured with traceability to national standards. The dose rate did not significantly affect D10 values (microbicidal effectiveness) for any of the Gamma-irradiated pathogens. Low energy X-ray irradiated pathogens had significantly higher D10 values (lower microbicidal effectiveness) for all pathogens compared to Gamma-irradiated pathogens. The combination of Gamma or X-ray irradiation with a mixture of oregano/thyme essential oil (EO) fumigation generally increased the microbicidal effectiveness compared to irradiation alone. Gamma or low energy X-ray irradiation and plant essential oils such as oregano/thyme, applied alone or in combination, are effective antimicrobial treatments. Highlights: Pathogens were treated with Gamma and X-ray irradiation at different dose rates. Dose rate did not significantly affect D10 values for the pathogens in rice. X-ray irradiated pathogens had higher D10 values than Gamma-irradiated pathogens. Irradiation with oregano/thyme essential oil increased the microbicidal effectiveness.