Развој на протокол за испитување на храна третирана со јонизирачко зрачење која содржи силикатни минерали со примена на метод на термолуминисценција

Abstract

The doctoral thesis entitled "Development of a protocol for thermoluminescence detection of irradiated food containing silicate minerals" carried out investigations of irradiated food from which silicate minerals can be isolated by thermoluminescence in standard and special conditions and comparative analysis with tests performed by photostimulated luminescence. The protocol has been developed in accordance with European and national rules and standards. This protocol enables fast and simple way of detection of irradiated food and can also be used in nonstandard conditions. In the process of development of the protocol for detection of irradiated food containing silicate minerals, procedures for the use of a thermoluminescence apparatus have been performed, as well as its calibration, definition of the measuring range and measurement with standard materials. The verification and validation of the protocol have been carried out by examining samples of irradiated food containing silicate minerals. The results of the developed protocol are compared with the results of an already established protocol for detection of irradiated food by photostimulated luminescence. In addition to the development of the protocol, an analysis of the luminescence signal dependence on several factors has been performed. These factors include: storage of samples for longer periods of time, exposure of samples to natural light for a certain period of time and artificial light at a certain illuminance for a certain period of time, absorbed dose value and the percentage of irradiated material in mixtures with unirradiated material. By confirmation of protocol efficiency in nonstandard conditions, proper identification of food is always enabled, thus fulfilling legal norms and protecting consumers’ rights and producers’ rights and obligations. The accuracy of the procedure is confirmed by intercomparative analysis with world-renowned laboratories. The results of the measurements in all phases of the research that are part of this doctoral thesis provide accurate identification of the samples as irradiated or unirradiated. Application of this protocol in nonstandard conditions confirms the dependency of luminescence intensity on length of storage time, exposure of samples to light, absorbed dose value and percentage of irradiated material in mixtures. These results confirm previous studies in the field, but also upgrade and improve them in terms of simplicity and efficiency of the used method.