• Title, Summary, Keyword: thermoluminescence (TL)

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Detection Properties of Irradiated Dried Fruits by Using Photo-stimulated Luminescence, Thermoluminescence, and Electronspin Resonance Methods (물리적인 방법(PSL, TL, ESR)을 이용한 방사선 조사 건조과일의 검지 특성)

  • Yoon, Young-Min;Park, Jae-Nam;Choi, Soo-Jeong;Park, Jong-Heum;Kim, Jae-Kyung;Byun, Eui-Baek;Lee, Ju-Woon;Han, In-Jun;Park, Jin-Gyu;Kim, Jae-Hun;Song, Beom-Seok
    • Journal of Radiation Industry
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    • v.8 no.1
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    • pp.11-15
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    • 2014
  • In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for freeze dried fruits which are not allowed to be irradiated in Korea. Apples and persimmons samples that had been dried with a freeze drier were irradiated at a dose of 1, 3, 5, 7, and 10 kGy, using a gamma radiator with a cobalt-60 source. With the PSL method, the dried apples showed photon counts of less then 700 counts/60 s (negative) in all the samples, whereas the dried persimmons that were gamma-irradiated above 3 kGy yielded photon counts of between 700 and 5,000 counts/60 s (intermediate). The TL results showed that this technique is useful for detecting irradiated samples; the TL ratios ($TL_1/TL_2$) measured for the food samples at an irradiation dose of 1 kGy were 0.13 for dried apples and 0.79 for dried persimmons. With regard to the results of ESR spectroscopy, the strength of the ESR signals from the dried fruits increased linearly in a dosedependent manner. However, the characteristic signal was not found in all the samples. In conclusion, the TL methods only can be used for the detection of gamma-irradiated dried apples and persimmons.

Analyzing a Physical Marker to Identify Irradiated Dried Garlic and Cabbage (건마늘과 건양배추의 방사선 조사여부 확인을 위한 물리적 마커 분석)

  • Kim, Dong-Gil;Ahn, Jae-Jun;Jin, Qiong-Wen;Lee, Ho-Cheon;Kwon, Joong-Ho
    • 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.

Dosimetric Properties of LiF:Mg,Cu,Na,Si TL pellets (LiF:Mg,Cu,Na,Si TL 소자의 선량계적 특성)

  • Nam, Young-Mi;Kim, Jang-Lyul;Chang, Si-Young
    • Journal of Radiation Protection and Research
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    • v.26 no.1
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    • pp.7-12
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    • 2001
  • Sintered LiF:Mg,Cu,Na,Si thermoluminescence (TL) pellets were developed for application in radiation dosimetry. In the present study, the TL dosimetric properties of LiF:Mg,Cu,Na,Si TL pellets have been investigated for emission spectrum, dose response, energy response, and fading characteristics. LiF:Mg,Cu,Na,Si TL pellets were made by using a sintering process, that is, pressing and heat treatment from TL powders. Photon irradiations for the experiments were carried out using X-ray beams and a $^{137}Cs$ gamma source at the Korea Atomic Energy Research Institute (KAERI). The average energies and the dose were in the range of 20-662 keV and $10^{-6}-10^{-2}\;Gy$, respectively. The glow curves were measured with a manual type TLD reader(System 310, Teledyne) at a constant nitrogen flux and a linear heating rate. For a constant heating rate of $5^{\circ}C\;s^{-1}$, the main dosimetric peak of glow curve appeared at $234^{\circ}C$, the activation energy was 2.34 eV and frequency factor was $1.00{\times}10^{23}$. TL emission spectrum is appeared at the blue region centered at 410 nm. A linearity of photon dose response was maintained up to 100 Gy. The photon energy responses relative to $^{137}Cs$ response were within ${\pm}20%$ at overall photon energy region. The fading of TL sensitivity of the pellets stored at the room temperature was not found for one year.

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Characteristics of Thermoluminescence and Electron Spin Resonance and Organoleptic Quality of Irradiated Raisin and Dried Banana During Storage (건포도와 건바나나의 감마선 조사와 저장기간에 따른 열발광 및 전자스핀공명 특성과 관능적 품질)

  • Jo, Deok-Jo;Kwon, Joong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.4
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    • pp.609-614
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    • 2002
  • The characteristics of thermoluminescence (TL) and electron spin resonance (ESR) and organoleptic qualities of gamma-irradiated raisin and dried banana were investigated during storage at 4$^{\circ}C$ for 6 months. The minerals separated from non-irradiated raisins showed TL glow curve (TL$_1$) with very low intensity around 200~30$0^{\circ}C$, while the irradiated samples at 1 kGy or more showed glow curves with higher intensity around 18$0^{\circ}C$, with linear increase by irradiation dose ($R^2$=0.9684), which made it possible to identify irradiated samples during 6 months. Moreover, TL ratios (TL$_1$/TL$_2$) through the reirradiation step at 1 kGy enhanced confidence in the identification of irradiated raisins. The ESR signals of multicomponent lines resulted from crystalline sugar radicals were shown in irradiated banana, identifying irradiated samples. The ESR signal intensity was dependent on irradiation doses ($R^2$=0.8977) and the signals were stable enough to be detected by 6th month after storage. Considering tile marketability of irradiated dried fruits during 6 months at low temperature TL and ESR analyses were shown suitable for the identification of irradiated raisins and dried banana, respectively.

Luminescence Detection Characteristics for Irradiated Dried Fishes Using PSL-TL System (Photostimulated luminescence-thermoluminescence 분석체계를 이용한 조사 처리된 건어류의 luminescence 판별 특성)

  • Kim, Moon-Young;Kim, Gui-Ran;Ahn, Jae-Jun;Park, Kun-Sang;Kim, Eun-Jeong;Lee, Kyung-Jin;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.45 no.1
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    • pp.8-12
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    • 2013
  • Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different irradiated dried fishes. All the non-irradiated samples provided PSL counts of lower than 700 (negative: $T_1$). Clear identification of irradiated sample was only possible for irradiated anchovy with PSL counts >5000; however, the results were unsatisfactory (not positive) for irradiated cod, dried filefish, hairtail, and herring samples. The contaminating silicate minerals were obtained by density separation or acid hydrolysis to perform TL analysis, which resulted in a low intensity of TL glow curve with a maximum peak after $250^{\circ}C$ for the non-irradiated samples that are irrespective of their kinds and methods for the mineral separation. The TL glow curves of high intensity with maximum peak in the temperature range of $150-250^{\circ}C$ were observed for all the irradiated samples. However, better results of TL glow curves and particularly of the TL ratio ($TL_1/TL_2$) were obtained when the minerals were separated by a acid hydrolysis method.

Physical and Microbiological Approach in Proving the Identity of Gamma-irradiated Different Teas

  • Kausar, Tusneem;Kim, Byeong-Keun;Kim, Dong-Ho;Kwon, Joong-Ho
    • 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.

The Detection of Irradiated Composite Seasoning Foods by Analyzing Photostimulated Luminescence (PSL), Electron Spin Resonance (ESR) and Thermoluminescence (TL) (PSL, ESR 및 TL 측정에 의한 복합조미식품의 방사선 조사여부 검지)

  • Kwon Joong-Ho;Kim Mi-Yeung;Kim Byeong-Keun;Chung Hyung-Wook;Kim Tae-Cheol;Kim Soo-Jin
    • Korean Journal of Food 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.

Detection of Irradiated Agricultural Products by Thermoluminescence(TL) (Thermoluminescence(TL)를 이용한 농산물의 방사선 조사유무 확인)

  • Woo, Si-Ho;Yi, Sang-Duk;Yang, Jae-Seung
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.525-530
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    • 2000
  • A study was carried out to establish the detection method of irradiated agricultural products cultivated in Korea by Thermoluminscece(TL). Samples were irradiated using Co-60 gamma rays at various doses(0.05, 0.1, 0.2, 0.3 and 0.5 kGy). After irradiation, separated minerals of the samples measured by TL. TL intensity increased with increasing doses and the irradiated samples were higher than the non-irradiated samples. TL first and second glow curves showed maximum TL temperature point at $176.16{\sim}190.08^{\circ}C$ and $143.84{\sim}146.56^{\circ}C$, respectively. All the irradiated samples can be classified correctly by the shape of the glow curve and the glow curve ratio. Correlation coefficients of ginger, carrot, potato and sweet potato were 0.9968, 0.8522, 0.9612 and 0.9071, respectively, that showed very high correlation between irradiation dose and TL intensity. Therefore, these results suggest that TL measurement is an useful detection method for irradiated agricultural products.

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Physicochemical Identification Characteristics of Irradiated Brown Rice, Soybean and Sesame Seeds during Storage (방사선 조사된 현미, 대두 및 참깨의 저장기간에 따른 방사선 조사여부의 이화학적 판별 특성)

  • Lee, Jeong-Eun;Ahn, Jae-Jun;Kwon, Joong-Ho
    • Korean Journal of Food Preservation
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    • v.19 no.1
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    • pp.37-46
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    • 2012
  • The identification characteristics of irradiated (0.5, 1, 2, and 4 kGy) brown rice, soybean, and sesame seeds were investigated using photostimulated luminescence (PSL), thermoluminescence (TL), and hydrocarbon analysis during 12-month storage. PSL-based screening was possible for the irradiated soybean and sesame seed samples up to 6 and 12 months, respectively. The TL glow curve shape, intensity, and ratio enabled the clear dose-dependent discrimination of all the non-irradiated and irradiated samples. The TL intensity decreased during storage, but the TL glow curve did not change qualitatively, which provided enough information to confirm the irradiation treatment of the samples over the storage period. Radiation-induced hydrocarbons were found in all the irradiated samples even at 0.5 kGy, throughout the storage period. 8-Heptadecene ($C_{17:1}$) and 1,7-hexadecadiene ($C_{16:2}$) originated from oleic acid, and 6,9-heptadecadiene ($C_{17:2}$) and 1,7,10-hexadecatriene ($C_{16:3}$) originated from linoleic acid, can be used as radiation-induced markers in identifying irradiated brown rice, soybean, and sesame seeds.