Analyzing a Physical Marker to Identify Irradiated Dried Garlic and Cabbage

The verification of irradiation treatments, using dried garlic and cabbage treated at 0-20 kGy, was investigated by analyzing the photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence (TL) characteristics of the samples. The PSL results showed that the photon counts/60 sec of the non-irradiated dried garlic and cabbage were 287-337, corresponding to negative, while those of the irradiated samples were 7511-54063 photon counts/ 60 sec, corresponding to positive, making it possible to discriminate the non-irradiated from the irradiated samples. In ESR analysis, the dried garlic irradiated at 20 kGy exhibited cellulose radicals, whereas the irradiated dried cabbage showed crystalline sugar-induced multi-component signals, which were not found in the non-irradiated samples. The ESR signal intensity significantly increased as the irradiation dose increase (R = 0.9369 - 0.9926). The TL glow curves of the irradiated samples appeared at a temperature interval of 150-250, which were significantly different from those of non- irradiated samples, showing a significant increase in TL signal intensity with irradiation dose (R = 0.9670 - 0.9768). To enhance the reliability of the results, the first glow curve (TL ) was compared with the second glow curve (TL ) obtained after a re-irradiation step at 1 kGy. The TL ratio (TL /TL ) was in good agreement with the reported TL threshold values for both the non-irradiated ( 0.1) samples.