A Theoretical Approach for the Determination and Mechanistic Interpretation of Radiation D10-value

In the design of the food irradiation process, the knowledge of the radiation resistance of the target organism in a specific food commodity is required. The D10-value, the radiation dose needed to inactivate 90% of the microbial load in the food medium, is used to relate the amount of absorbed energy to the surviving bacterial population. Numerous experimental studies have been performed to determine the D10 values of several food-borne microorganisms irradiated under various conditions. Nevertheless, accurate predictions of D10 values of the pathogens in food products that have not been empirically examined cannot be made due to insufficient understanding of the biological response to radiation exposure. A theoretical model for the derivation of the D10-value has been proposed in this study to mechanistically assess the production of radiation-induced DNA damage by energetic electrons. The step-by-step Monte-Carlo simulation technique, which employs the detailed histories of the ionizing particles and the radiolytic species, was utilized. The effects of selected parameters including the genomic sequence, the type of DNA double strand break, the DNA damaging agents, the radical scavengers, the degree of dispersion of DNA molecules, and the number of genome equivalents were hypothetically investigated. The developed computational methodology as well as the results presented can be used as an analytical tool to evaluate the impact of ionizing radiation on cell survival.