|CHEN, HAIQIANG - University Of Delaware|
|LI, XINHUI - University Of Delaware|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/3/2014
Publication Date: 6/21/2014
Citation: Lacombe, A.C., Niemira, B.A., Gurtler, J., Boyd, G., Sites, J.E., Chen, H., Li, X. 2014. Nonthermal inactivation of the norovirus surrogate tulane virus on blueberries using atmospheric cold plasma. Meeting Abstract., IFT Annual Meeting., New Orleans, LA., June 21-24, 2014., Volume 1, Page 1.
Technical Abstract: Viruses are currently the leading cause of foodborne outbreaks, most of which are associated with foods consumed raw. Cold plasma (CP) is an emerging novel nonthermal technology that can be used for the surface decontamination of foods. This study investigated CP technology for the nonthermal inactivation of the human norovirus surrogate, Tulane virus (TV), on the surface of blueberries. Blueberries (5g) were weighed into sterile 4 oz. glass jars and inoculated with 500 ul of TV (5 log PFU/g). Samples were treated with atmospheric CP for 0, 15, 30, 45, and 60s at a working distance of 7.5 cm with 4 cubic feet/minute (cfm) of CP jet. Temperature readings were taken with an infrared camera prior to and following CP treatments. In order to establish the impact of air flow during CP treatment (4 cfm), an additional 7 cfm jet of room temperature air was introduced from a separate nozzle. The experiment was then repeated with 90 and 120 seconds as additional time points. Viral titers were measured immediately after each treatment with a plaque assay using LLC-MK2 cells. CP alone significantly (P less than 0.05) reduced TV by 2 log PFU/g TV after a treatment of 60s. However, this level of treatment also created thermal conditions (berry surface temperature greater than 56C) after 30s. In contrast, berries treated with the mixture of CP and normal air remained under 50C for up to 120s. This mixture also retained much of the antiviral efficacy of CP alone, with a significant reduction of 1.6 log PFU/g after 45s. These results demonstrate that CP viral inactivation does not rely on thermal inactivation, and is therefore nonthermal in nature. Therefore, with further optimization, CP may be used by food processors as a means of nonthermal inactivation of foodborne viruses.