Submitted to: Food and Environmental Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2019
Publication Date: 4/4/2019
Citation: Kingsley, D.H., Annous, B.A. 2019. Evaluation of steady state gaseous chlorine dioxide treatment for the inactivation of tulane virus on berry fruits. Food and Environmental Virology. https://doi.org/10.1007/s12560-019-09382-4.
Interpretive Summary: Pathogenic human viruses are a substantial problem for the fresh and frozen berry industry principally because they are environmentally prevalent and very difficult to inactivate. We demonstrate that treatment with constant low levels of gaseous chlorine dioxide can inactivate a human norovirus surrogate on the surface of strawberries, blueberries, blackberries and raspberries. Use of direct constant level chlorine dioxide as opposed to bolus type sachet treatments circumvent issues regarding oxidative burden of different produce products permitting equal treatments regardless of the lot size being treated. This work should serve as a guideline for the industry regarding treatment of berries with chlorine dioxide gas.
Technical Abstract: The effectiveness of steady state levels of gaseous chlorine dioxide (ClO2) against Tulane virus (TV), a human norovirus surrogate, on berries was determined. The generated ClO2 was maintained at 1 mg/L inside a 269 liter glove box to treat two 50g batches of blueberries, raspberries, and blackberries, and two 100 g batches of strawberries that were immersion coated with TV. The normalized treatment concentrations of ClO2 ranging from 0.63 to 4.40 ppm-h/g berry were evaluated. When compared to untreated TV-contaminated berries, log reductions of TV were >2.9 for all berry types and conditions tested indicating the gaseous ClO2 was highly effective. The effect of ClO2 concentrations used on log reductions of TV on all berry were not significantly different (p < 0.05). The average log reduction with strawberries, raspberries, blueberries and blackberries, treated with 0.63 ppm-h/g, the lowest concentration tested, were 2.98, 3.40, 3.82, and 4.17 respectively. Overall results suggest that constant levels of ClO2 are quite effective against foodborne viruses.