Simulation study to assess the effectiveness of gamma radiation for inactivation of viruses on food packaging material

The recent COVID-19 pandemic spread across the globe has raised the concern about the possible transmission of viruses through food packaging material during domestic and international trade. Therefore, mitigation strategies are needed to address these safety issues. Preliminary in-silico study showed that interactions between food packaging material and viral surface proteins were possibly hydrophobic in nature with most favourable interaction having a binding free energy of −5.24 kcal/mol. Since these interactions can cause viruses to adsorb on the food packets and get transmitted during supply chain, it is necessary to inactivate the viruses. In this context, efficacy of gamma irradiation in inactivating the viruses on the food packaging material was assessed. For this simulation study P1 (virulent) bacteriophage of E. coli was used as a model system. Gamma irradiation of food packets at an absorbed dose >8 kGy was found to completely inactivate the infectivity of P1(virulent) bacteriophage when co-cultured with E. coli host and assayed for viral plaque formation. Reduction in infectivity of P1(vir) phage was more prominent at ambient temperature (25 ± 2 °C) as compared to cold temperature (6 ± 2 °C) when assayed after storage (one week). Gamma irradiation (2 kGy) completely inactivated the virus particles on food packets when stored for 1 week at both the above temperatures. It is thus proposed that gamma irradiation (2 kGy) can possibly be integrated as a final treatment of the packaged food products to rule out the possibility of viral transmission. However, the efficacy of radiation processing against different pathogenic viruses needs to be determined prior to actual commercial deployment.