Location: Produce Safety and Microbiology ResearchTitle: Scale-up model of forced air integrated gaseous chlorine dioxide for the decontamination of lowbush blueberries
Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2020
Publication Date: 3/15/2020
Citation: Lacombe, A.C., Antosch, J.G., Wu, V.C.H. 2020. Scale-up model of forced air integrated gaseous chlorine dioxide for the decontamination of lowbush blueberries. Journal of Food Safety: e12.
Interpretive Summary: A recent recall on frozen berries suspected to be contaminated with hepatitis A virus has caused concerns about produce safety. There is a need for post-harvest sanitization of berries. We investigated a gas form of chlorine dioxide (ClO2) that could aid in the removal of microorganisms from frozen foods. A pallet containing 110 pounds of frozen blueberries was fumigated with gaseous chlorine dioxide and kept in the treatment condition for 10 hours. The results demonstrated a 90% reduction in possible fecal contaminants. This experiment was unique because of the scale of the fumigation chamber and number of blueberries treated. These findings support the use of gaseous chlorine dioxide in improving produce safety.
Technical Abstract: Recent outbreak in frozen berries has spurred concerns about post-harvest contamination of blueberries. Gaseous chlorine dioxide is a promising sanitizer for frozen products because of its efficacy under nonthermal conditions. However, a major knowledge gap exists between laboratory efficacy trials and effectiveness at the industrial scale. To address this, a pallet sized fumigation container (60 harvest totes) was designed for a pilot trial of gaseous ClO2 treatment on 50 kg of lowbush blueberries with an initial dose of 57.46 mg/L. Reduction of all viable cells, coliforms, yeasts, and molds were measured by plating treated samples on Tryptic Soy Agar (TSA), Violet Red Bile Agar (VRB), and Dichloran Rose Bengal chloramphenicol agar (DRBC) and compared to untreated controls. The results demonstrate that a significant reduction of 1.5 log CFU/g can be achieved against coliforms after 10 hours of ClO2 exposure representing a treatment of 2.35 mg/g of blueberries. Our findings demonstrate a cost-effective procedure that could be adapted to commercial processing.