In vitro virucidal activity of active food packaging based on monoglycerides against a Human Coronavirus and other viruses

INTRODUCTION The ongoing pandemic by SARS-CoV-2 has generated an increased demand for materials with virucidal properties, also in the field of food packaging. A solid body of evidence documents the microbicidal activity of lipids, such as fatty acids and monoglycerides, on a large spectrum of microorganisms. In this work, virucidal activity of four different formulations based on monolaurin and monocaprine, were tested on betacoronavirus HCoV OC43, Herpesvirus HSV-1 and the Adenovirus AdV-5. The first aim was to assess the most active formulation against these viruses. In a next step, the best performing formulation was used as antimicrobial agent to develop a film as active food packaging. MATERIALS AND METHODS Each of the 4 lipid formulations was tested at different concentrations and times of contact by incubating the virus suspensions with each formulation for 10 and 20 minutes followed by titration with end point dilution. In a second phase the most active formulation was used to prepare a packaging film which was tested for its ability in inactivating HCoV OC43 and HSV-1 but not AdV which resulted not invactivated by any of the 4 formulations. The virucidal activity of this active packaging was tested at different concentrations and time of contact, up to 24 hour. Briefly, the films were contaminated with the viruses under study and at different time points the film samples were soaked in 1ml of cell growth medium and vortexed for 1’ to eluate the survived virus. Viral loads of these suspensions were titrated by end point dilution on cell cultures. RESULTS All the four formulations tested were found active on HCoV OC43 and HSV-1 (in some cases with a reduction >4 Log) but not on AdV-5. The packaging film showed a remarkable reduction of the viral load of both virus (>2,5 Log). DISCUSSION These results confirm that natural compounds with antiviral properties for active food packaging may represent a new and promising strategy for virus transmission.