Chlorine dioxide (ClO2) is a promising antimicrobial with various food applications, one of those being inclusion in packaging. The purpose of this study was to evaluate a novel ClO2-based antimicrobial packaging system (InvisiShield™) for its efficacy against human norovirus (hNoV) and hepatitis A virus (HAV) in refrigerated fresh produce.
Grape tomatoes or blueberries were placed in polypropylene trays and selectively inoculated with 6.0 log10 hNoV Genome Equivalent Copies (GEC; 20% stool suspension) or 6.2 log10 HAV GEC (cell culture lysate). Trays were heat sealed with a three-phase polymer film consisting of a base, channeling agent, and the ClO2 active (treatment); or control (no active) film and stored at 7°C for 24, 48 h, and 7 days. At each timepoint, the product was collected and processed for virus concentration using the sequential steps of elution and polyethylene glycol precipitation. Viruses in extracts were quantified using RNase-RT-qPCR.
Log10 reductions (LR) in hNoV GEC for tomatoes were 2.2 ± 1.3, 2.9 ± 0.7, and 3.6 ± 0.3, after 24, 48 h and 7 days, respectively. For blueberries, hNoV LR were 1.4 ± 0.7, 1.7 ± 0.5, and 2.7 ± 0.2 GEC, respectively. Hepatitis A virus GEC LR were 0.4 ± 0.2, 1.0 ± 0.1, and 2.1 ± 0.7 for tomatoes, and 0.1 ± 0.2, 1.2 ± 0.4, and 3.2 ± 0.2 for blueberries, after 24, 48 h and 7 days, respectively. Position of the fruit in the tray did not affect inactivation (