THEORETICAL APPROACH FOR THE CALCULATION OF RADIATION D10-VALUE
In the design of the food irradiation process, the knowledge of the radiation resistance of the target organism in the 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 fractional population of the viable cells. Numerous experimental studies have been performed to determine the D10 values of several food borne microorganisms irradiated under various conditions. Nevertheless, accurate prediction of D10 value for a radiation treatment of a food product that has not been empirically examined can not 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 DNA damage by energetic electrons. The step-by-step Monte-Carlo simulation technique which employed the detailed histories of the ionizing particles and the radiolytic species was utilized. The impacts of the genomic sequence, the number of the genome equivalents, and the method of DNA double strand break determination were hypothetically investigated. The developed computational methodology as well as the results presented can be used as an analytical tool to evaluate the effect of ionizing radiation on the cell survival. PRACTICAL APPLICATIONS
The presented methodology can be employed as an investigative technique complementary to other approaches to understand the physical, chemical and biological changes in food-born pathogens exposed to e-beam.
Document Type: Research Article
Publication date: February 1, 2010