Effect of initial dose on thermoluminescence intensity of mineralsfrom irradiated food

Abstract

Thermoluminescence analysis is one of the most useful technique in discriminating between irradiated and unirradiated food. This is applicable to many foodstuffs if inorganic minerals adhering to food is successfully isolated. This paper reports, using both inorganic minerals isolated from black pepper and quartz free from organiccontaminant, findings about temperature region where stable TL signal is gained and the effect of higher initial doses on TL intensities after re-irradiation.
TL signals between 150-250°C decayed with the storage time after irradiation while signals between250-450°C with maximum peak at 360°C were more stable. Thus the author prefers to obtain TL ratio after reirradiationfrom TL intensities between 250-450°C for more clear identification.
It was found that the higher the dose exposed to inorganic minerals is, the higher TL intensity after reirradiation becomes. This suggests annealing at higher temperature is necessary before a normalization step for clear identification.