الفهرس 
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Abstract
Food irradiation is used to reduce the health risk associated with food-borne pathogens such as Salmonella, and prolong shelf life (sprout inhibition, delay of ripening). The choice of irradiation method depends on the materials to be treated. In fact, ionizing radiation is effective in food conversation because high-speed electrons, gamma rays inhibits the division of microorganisms and creates so-called radiolytic products as well as free radicals, which are relatively stable especially in dry environment.
A range of analytical methods have been successfully developed to detect such free radical in the irradiated food. These are based on the detection of physical, chemical and microbiological changes that can occur in irradiated food. The most useful and widely used methods include electron spin resonance spectroscopy (ESR), thermoluminescence methods (TL), and photostimulated luminescence (PSL).
Irradiated poultry bones, or dried spices may contain a substantial amount of stable radicals which can be easily detected by electron paramagnetic resonance spectroscopy (EPR). Electron paramagnetic resonance (EPR), as an analytical technique used for food irradiation dosimetry, is characterized by easy, fast, and reliable detection of irradiated.
In this study several kinds of irradiated food using gamma radiation sources such as Cs-137 and Co-60 are considered. Which are:
• Carbohydrates, such as sucrose, glucose, fructose and starch.
• Shell and kernel of nuts, such as hazelnut, walnut and pistachio.
• Bones, such as fish back bone and meat bovine bone.
• Sea foods, such as pink shrimp shell and sea food shell.
The procedures of samples preparations and the equipment used for the measurements are described. In addition, the experimental setup, the measured parameters and the calibration of the used facilities are clearly determined.
The EPR spectral features of each of the studied materials, the effect of modulation amplitude and microwave power on the peak-to-peak intensity, short and long-term dependence, and the radiation response for each material are studied.
Based on the obtained results, it was concluded that all the detected EPR signal due to the radiation induced free radical in the studied irradiated food by γ sources with doses in the range 0.5 to 10 kGy, are stable enough to be used for dose assessment. The obtained results are also represented in tables and curves. These curves are well fitted with clear fitting equations and high correlation coefficients. characterized by easy, fast, and reliable detection of irradiated