• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.136-140
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• 2009

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 ($R^2$= 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 ($R^2$= 0.9670 - 0.9768). To enhance the reliability of the results, the first glow curve ($TL_1$) was compared with the second glow curve ($TL_2$) obtained after a re-irradiation step at 1 kGy. The TL ratio ($TL_1/TL_2$) was in good agreement with the reported TL threshold values for both the non-irradiated (<0.1) and irradiated (> 0.1) samples.

• 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.

• Food Science and Preservation
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• v.13 no.1
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• pp.55-60
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• 2006

Two kinds of composite seasoning products (beef broth powder, polk bone extract powder) were used for a detection trial of gamma irradiation treatment up to 10 kGy by analyzing photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence(TL). PSL results showed that the photon counts of non-irradiated samples were lower than 700, while those of irradiated samples were higher than 5000, which makes it possible to screen irradiated composite seasoning products at 1 kGy or over from the non-irradiated control. ESR signals measured for both irradiated samples were not irradiation-specific, even though they were dose dependent in the signal intensity. Radiation-induced TL glow curves were found in irradiated beef broth powder and furthernmore, TL ratio $(TL_4/TL_2)$ obtained by a re-irradiation step could verify the detection result of TL1 glow curves, showing ratios lower than 0.05 in the non-irradiated sample and higher than 1.00 in irradiated ones.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.673-679
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• 2012

Ten commercially available red pepper powders were investigated using photostimulated-luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) analyses to confirm their irradiation status. The application of PSL, TL, and ESR analyses was also confirmed by in-house irradiation. In PSL-based screening, all samples gave negative photon counts (<700 PCs). The PSL calibration dose (1 kGy) showed a low sensitivity of 4 samples, while the others provided reliable screening results. TL glow curves demonstrated maximum peaks after $250^{\circ}C$ for the 6 samples; however 4 samples gave complex TL glow curves with maximum peaks in the range of $185-260^{\circ}C$ (radiation-specific), which could be the effect of an irradiated component in low concentration as the TL ratios of all samples were <0.1. Radiation-specific ESR features were absent in the all commercial samples. Variable irradiation detection properties were found; where the TL analysis showed the possible presence of an irradiated component in 4 samples requiring further monitoring and investigation.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.648-652
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• 2010

This study was performed to investigate PSL and TL characteristics for the detection of different ratios of gamma-irradiated turmeric. It was possible to determine PSL and TL of 1- and 10-kGy irradiated turmeric. The TL ratios ($TL_1/TL_2$) of non-irradiated samples were lower than 0.001, while those of irradiated samples were higher than 0.355. In the PSL results, blended samples containing irradiated ingredients showed intermediate values for a 1% blending rate. Furthermore, TL analysis of blended samples seems to offer a promising method for irradiation identification by TL glow curve form and temperature range. The 1- and 10-kGy irradiated samples were able to be detected above a 4% blending rate. However, the TL ratio appeared as a threshold value below 0.1 for irradiated samples. Overall, TL analysis identified 4% blended samples containing gamma-irradiated turmeric.

• Current Research on Agriculture and Life Sciences
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• v.30 no.2
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• pp.82-89
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• 2012

Commercial powdered soups, such as potato soup(PS), corn soup(CS), and chicken-herb soup(CHS), were gamma-irradiated at 0, 1, 5 and 10 kGy and subjected to physicochemical evaluation and identification trials by analyzing photostimulated luminescence(PSL), electron spin resonance(ESR), and thermoluminescence(TL). The changes in moisture content and pH of soup samples were negligible upon irradiation. The Hunter's color determinations showed that lightness (L value) decreased and yellowness (b value) increased as the irradiation dose increased in PS sample. The viscosity of irradiated samples was reduced in the order of PS, CS and CHS. The analyses of PSL, ESR and TL were applicable to the identification of irradiated powdered-soups at more than 1 kGy by detecting PSL photon counts/60 sec(over 5000), radiation-induced multicomponents-ESR signal, and typical TL glow curve at $150-250^{\circ}C$.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.85-91
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• 2014

The purpose of this study is evaluated scatter radiation in digital radiological condition by using photo-stimulated luminescence (BaFBr:$Eu^{2+}$). Experiment condition changed kVp (from 50 kVp to 120 kVp), filed size (from $4{\times}4cm^2$ to $26{\times}26cm^2$) and phantom thickness (from 1 cm to 15 cm). This method was analysed ImageJ and characteristic curve of CR. This results was scatter radiation to primary radiation ratio increased from 50 kVp to 70 kVp, and it was fixed at over 80 kVp. The scatter radiation to primary radiation ratio are increased according to increasing the ratio of field size. Scatter radiation is also increased by increasing the phantom thickness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1837-1842
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• 2013

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different gamma-irradiated dried fishes (mussel, squid, beka squid, mitra squid, plaice, and saury) at 0, 1, 5 and 10 kGy. For TL analysis, the contaminating silicate minerals were obtained by density separation or acid hydrolysis treatment. PSL determinations indicated that all the non-irradiated samples showed PSL photon counts/60 s (PCs) lower than 700 PCs (negative), but the irradiated mussel sample at 5 and 10 kGy were only possibility identified showing higher than 5000 PCs (positive). Irrespective of sample kinds and methods of mineral separation, all the non-irradiated samples showed TL glow curves in low-intensity with a maximum peak only after $250^{\circ}C$. However, all the irradiated samples produced TL glow curves in high intensity with a maximum peak particularly in the temperature range of 1$150{\sim}250^{\circ}C$. In conclusion, more distinguishable TL results [glow curve, TL ratio ($TL_1/TL_2$)] were obtained from the marker minerals separated by acid hydrolysis rather than density method.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.167-173
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• 2013

Dried fish products, such as seasoned cuttlefish, anchovy, and filefish, were analyzed to investigate the physicochemical quality and luminescence properties following gamma-irradiation. The overall color difference slightly increased in all irradiated samples, showing significant changes in Hunter's L, a, and b color values. Cuttlefish and filefish showed higher values in hydrophilic browning, whereas anchovy showed a higher value in lipophilic browning. The brown color intensity of filefish showed a dose-dependent increase. The thiobarbituric acid (TBA) value significantly increased in irradiated samples of cuttlefish and anchovy, which have relatively high lipid contents. Irradiated samples, except anchovy, were not suitable for screening using photostimulated luminescence (PSL) because only negative or intermediate values were observed. Thermoluminescence (TL) measurements were suitable for all fish samples, i.e., irradiation-specific glow curves were obtained, signal intensity increased, and the TL ratio fulfilled the criterion. There was no significant difference among the irradiated samples with regard to the sensory properties.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.1-5
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• 2005

Photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR), and direct epiflourescent filter technique/aerobic plate count (DEFT/APC) were applied to detect dried green, black, and oolong teas irradiated between 0-10 kGy. Teas irradiated at 2.5 kGy and higher showed over 5000 photon counts/60 sec, while non-irradiated teas yielded 650-1000 photon counts/60 sec. TL glow curves for minerals separated from teas were detected at about $300^{\circ}C$ with low intensity in non-irradiated samples, whereas around $150^{\circ}C$ with high intensity in all irradiated samples. Ratio of $TL_1/TL_2$ based on re-irradiation step, showing lower than 0.1 and higher than 1.44 for non-irradiated and irradiated samples, respectively, enhanced reliability of TL results. ESR measurements for irradiated teas showed signals specific to irradiation. Log DEFT/APC ratio increased with irradiation dose; this result could be applied to identify irradiated tea samples.