Development of antiviral edible films against Tulane virus, a human norovirus surrogate, for use on strawberries

Abstract

This study developed and evaluated the antiviral properties of edible films against Tulane virus, a human norovirus surrogate. The antiviral properties of carvacrol, grape seed extract (GSE), and green tea extract (GTE) edible films were first assessed through a 24 h film immersion method. Edible films at concentrations of 5%, 10%, and 15% GTE showed promising antiviral activities as they decreased the viral titer to undetectable levels (>4.0-4.1 log). Due to these results, GTE edible films were used for the remainder of the experiments. Evaluated through spot inoculation with 24 h incubation, 5%, 10%, and 15%-GTE edible films achieved significantly higher reductions of Tulane virus compared to the control film (1.8-2.4 log). When the 5%, 10%, and 15%-GTE edible films were tested on quartered strawberries, the 10%-GTE film caused a significant decrease in the titer of Tulane virus (0.8 log); however, none of the tested films were able to achieve >1-log reduction. Results from this study suggest that although GTE films had shown strong antiviral capabilities in the full immersion and spot inoculation experiments, further research is still needed to develop edible films that can be applied on food products to control foodborne viruses.