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Detection of Radiation - Induced Hydrocarbons in Green, Black and Oolong Teas
Tusneem Kausar,Jungeun Lee,Jungeun Noh,Youngju Kwon,Joong-Ho Kwon 한국식품영양과학회 2004 Preventive Nutrition and Food Science Vol.9 No.3
Hydrocarbons induced by gamma-irradiation of green, black, and oolong teas were analyzed to determine whether the hydrocarbons can be used as markers for detecting post-irradiation of these teas. The samples were irradiated at 0, 2.5, 5, 7.5, and 10 kGy. Detection was attempted by extracting fat from the teas, separation of hydrocarbons with florisil column chromatography, and identification of hydrocarbons by gas chromatography-mass spectroscopy (GC-MS). Concentration of hydrocarbons increased with the irradiation dose. The major hydrocarbons in irradiated green, black, and oolong teas were 1-tetradecence (14:1), pentadecane (15:0), 1,7-hexadecadiene (16:2), 1-hexadecene (16:1), 8-heptadecene (17:1), and heptadecane (17:0). Radiation-induced hydrocarbons in teas were 1,7- hexadecadiene and 8-heptadecene. These compounds were not detected in non-irradiated samples, so the hydrocarbons (16:2, 17:1) can be used as markers for detecting post-irradiation of the teas. Furthermore, detection of hydrocarbons after 12 months storage at room temperature remains a suitable method for identifying irradiated teas.
Kausar, Tusneem,Kim, Byeong-Keun,Yang, Jae-Seung,Byun, Myung-Woo,Kwon, Joong-Ho The Korean Society of Food Science and Nutrition 2004 Preventive Nutrition and Food Science Vol.9 No.3
Green, black and oolong teas were irradiated by $^{60}$ Co-gamma rays (0~10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650~1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively. The TL glow curves for minerals isolated from the non-irradiated teas were situated at about 30$0^{\circ}C$ with a low intensity, but for irradiated samples were approximately 15$0^{\circ}C$ with a high intensity. The TL ratios (TL$_1$/TL$_2$), calculated from values after initial radiation and then after re-irradiation of the teas, were below 0.1 for the non-irradiated samples and higher than 1.44 for all irradiated samples, enhanced the reliability of the identification results for TL. The signal intensity of PPSL and TL for irradiated teas decreased with the lapse of post-irradiation storage time at room temperature but was still distinguishable from that of the non-irradiated samples even after one year.
Tusneem Kausar,Byeong-Keun Kim,Jae-Seung Yang,Myung-Woo Byun,Joong-Ho Kwon 한국식품영양과학회 2004 Preventive Nutrition and Food Science Vol.9 No.3
Green, black and oolong teas were irradiated by (60)^Co-gamma rays (0~10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650~1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively. The TL glow curves for minerals isolated from the non-irradiated teas were situated at about 300℃ with a low intensity, but for irradiated samples were approximately 150℃ with a high intensity. The TL ratios (TL₁/TL₂), calculated from values after initial radiation and then after re-irradiation of the teas, were below 0.1 for the non-irradiated samples and higher than 1.44 for all irradiated samples, enhanced the reliability of the identification results for TL. The signal intensity of PPSL and TL for irradiated teas decreased with the lapse of post-irradiation storage time at room temperature but was still distinguishable from that of the non-irradiated samples even after one year.
Properties of PSL, TL, and ESR to Identify the Irradiated Sesame Seeds after Steaming
Jeongeun Lee,Tusneem Kausar,Hyung-Wook Chung,Il-Yun Jeong,Ijaz A. Bhatti,Joong-Ho Kwon 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.2
Three physical methods, photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR), have been applied to detect the irradiation treatment for the non- and steamed sesame seed samples. PSL successfully screened the irradiated samples from the non-irradiated control by comparing their photon counts (PCs) with the lower (less than 700 count/60 sec) and upper threshold values (higher than 5,000 count/60 sec). TL signals were still detected in all irradiated samples even after steaming, which was reconfirmed with TL ratios [integrated area of TL₁ (the first glow)/TL₂ (the second glow)] through re-irradiation step. ESR spectrometry showed that radiation-induced cellulose radicals were detected in all the irradiated samples irrespective of steaming treatment. Identification of the irradiated sesame seeds was possible even after steaming by analyzing PSL, TL, and ESR.
권중호,이은주,Tusneem Kausar,AhnDongUk 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.6
The effect of adding 10% fat substitute (10%F) or 2% plum extract (2%P) on the formation of hydrocarbons and 2-alkylcyclobutanones (2-ACBs) in freeze-dried beef patties, irradiated (IR) at 44 kGy, and freeze-dried irradiated cooked beef patties was investigated. Hydrocarbons, such as C_(16:3), C_(16:2), C_(17:2) and C_(17:1), were detected only in irradiated samples and their concentrations were high in the order of 2%P+IR, IR and 10%F+IR. Only irradiated beef samples produced 2-ACBs (2-DCB, 2-TCB, 2-TeCB), and their amounts were high in reverse order. The addition of fat substitute or plum extract did not help in reducing hydrocarbons and 2-ACBs in the freeze-dried irradiated cooked beef. However, the amounts of radiationinduced hydrocarbons and 2-ACBs in all irradiated beef patties even at 44 kGy were too small to be of concern for human consumption.
Kwon, Joong-Ho,Kausar, Tusneem,Noh, Jungeun,Kim, Dong-Ho,Byun, Myung-Woo,Kim, Kyong-Su,Kim, Kwan-Soo Pergamon 2007 Radiation physics and chemistry Vol.76 No.11-12
<P><B>Abstract</B></P><P>Dried seasoned filefish (<I>Thamnaconus modestus</I>) was irradiated at 0–10kGy and the identification of irradiation treatment was investigated by analyzing the characteristics of thermoluminescence (TL), hydrocarbon (HC), and 2-alkylacyclobutanone (2-ACB). The TL (TL<SUB>1</SUB>), glow curve of the irradiated samples peaked at approximately 150°C with high intensity, but that of the non-irradiated samples peaked at about 300°C with little intensity, thus making it possible to discriminate between irradiated and non-irradiated samples. Moreover, TL ratio (TL<SUB>1</SUB>/TL<SUB>2</SUB>), through normalization steps, enhanced the reliability of the TL<SUB>1</SUB> results. Six kinds of HCs and three kinds of 2-ACBs quantitatively determined for the samples linearly increased in proportion to irradiation doses. In particular, two HCs like 1-hexadecane and 1,7-hexadecadine, and three ACBs, such as 2-dodecylcyclobutanone, 2-(5′-tetradeceyl)cyclobutanone, and 2-tetradecylcyclobutanone, were identified only in the irradiated samples as radiation-induced markers.</P>