Identification of low amount of irradiated spices (red pepper, garlic, ginger powder) with luminescence analysis

For the identification of irradiated food, current analysis methods have limitations regarding presence and stability of radiation-induced markers. In this study, different spice blends with small quantity of different irradiated (0, 1 and 10 kGy) spice powders, such as red pepper, garlic or ginger, were investigated using PSL and TL techniques. In PSL-based screening analysis, the spice blends containing 10% of irradiated materials (1 or 10 kGy) were determined as intermediate or positive. In TL results, the blends containing 1% of 1 or 10 kGy-irradiated spices showed the typical TL glow curves that could be interpreted as positive. The blends with irradiated garlic powder provided more good results where identification was possible at 0.5% mixing of irradiated sample. However, the TL ratios of all spice blends were <0.1 and only TL glow curve shape and intensity may be used to discriminate the samples having irradiated component.

► Sample blends with small quantities of irradiated spices were evaluated.
► The PSL was inappropriate to detect irradiated ingredient in small quantity.
► TL glow curve shape and intensity could be used as conclusive evidence of irradiation.
► TL ratios of all irradiated and nonirradiated samples were <0.1.