Investigation of spectroscopic and dosimetric properties of some irradiated food and paper samples by ESR technique

Nowadays, within certain limits, ionizing radiation sources are used routinly for the sterilization of foods and protection of books and documents that can be considered as cultural heritage. Electron Spin Resonance (ESR) technique is one of the most reliable techniques for the identification of food or paper samples irradiated with ionizing radiation. In this study, spectroscopic properties of free radicals produced by irradiation effect in various food and paper samples were investigated by ESR technique. Different food and paper samples were irradiated with gamma radiation source and the changes in the spectral properties of the ESR signals caused by the radiation effect in the irradiated samples were followed by time, temperature, microwave power and irradiation dose. Long term fading behavior of radicals was investigated by measuring the signal intensities of the samples kept under normal laboratory conditions. In addition, by using the data obtained from high temperature kinetic studies, the activation energies of radiation induced free radicals in food and paper samples were calculated. In the light of the obtained results, it was discussed whether the pre-irradiation process of the investigated samples could be determined by ESR technique and whether they can be used as a dosimetric material.