• Journal of Radiation Industry
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• v.4 no.3
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• pp.221-226
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• 2010

Physical detection methods, photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) were applied to detect electron beam-irradiated agricultural products, such as red pepper, black pepper, raisin, walnut, beef seasoning and pistachio. The absorbed irradiation doses for representative samples were controled at 0, 1, 3, 5 and 10 kGy. PSL values for non-irradiated samples were <700 counts/60s (lower threshold, $T_1$) except beef seasoning, whereas those of irradiated samples were more than 5,000 photon counts, upper threshold ($T_2$) in black pepper, raisin, and beef seasoning and intermediates values of $T_1-T_2$ in red pepper, walnut, and pistachio. Minerals seperated from the samples for TL measurement showed that non-irradiated samples except pistachio (TL ratio, 0.12) were characterized by no glow curves situated at temperature range of $50{\sim}400^{\circ}C$ with TL ratio (0.01~0.08), while irradiated samples except pistachio at only 1 kGy (TL ratio, 0.08) indicated glow curve at about $150{\sim}250^{\circ}C$ with TL ratio (0.28~3.10). ESR measurements of irradiated samples showed any specific signals to irradiation. The samples of both red pepper and pistachio were produced specific signals derived from cellulose radicals as well as single line signals for black pepper and walnut, and multiple signals derived from crystalline sugar radicals for raisin and beef seasoning. In conclusion, The ESR methods can apply for detection of pistachio exposed to electron beam but PSL and TL are not suitable methods. Furthermore, TL and ESR suggeted that both techniques were more useful detection method than PSL to confirm whether red pepper, walnut and beef seasoning samples have been exposed to electron beam.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.256-261
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• 2014

This study was conducted to determine the effect of gamma-ray and electron-beam irradiation on dried spices (black pepper, red pepper, parsley, and basil) using the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods. The spices were irradiated at 0, 1, 5, and 10 kGy. All non-irradiated spices had photon counts (PCs) less than 700 PCs. The PCs of three irradiated spices (red pepper, parsley, and basil) were clearly distinguishable from those of non-irradiated ones, exhibiting PSL signals higher than 5000 PCs. However, negative PSL counts (<700 PCs) were obtained for most irradiated black pepper, except those irradiated with 5 kGy gamma rays and 10 kGy electron-beams. TL glow curves of the irradiated spices showed a higher peak at $150-250^{\circ}C$. TL ratios were found to be less than 0.1 for non-irradiated spices and higher than 0.1 for irradiated ones. No ESR signal was observed for any irradiated spice except red pepper, which displayed cellulose-based ESR spectra. Therefore, the results suggest that the PSL, TL, and ESR methods are effective detection techniques for dried spices irradiated with electron beams as well as gamma rays.