• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.136-141
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• 2000

The properties of pulsed photostimulated luminescence (PPSL) were measured to use as basis data for the detection of irradiated foodstuffs (34 different foods). Samples were packed in polyethylene bags and irradiated at 1, 5, and 10 kGy with a dose rate of 10 kGy/h. The samples irradiated were introduced in the sample chamber without other preparation and measured PPSL photon counts for 60 and 120 s. The PPSL photo counts of the irradiated samples were higher than the unirradiated, increased with increasing irradiation dose, and showed a good relationship between irradiation doses and photon counts in a multinomial expression. These results suggest that the detection of irradiated foodstuffs was possible by PPSL. Therefore, PPSL can be proposed as the method for the detection of irradiated foodstuffs.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.145-150
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• 2005

This study was carried out to examine the properties of sample amount and storage conditions on the accumulated pulsed photostimulated luminescence (PPSL) signals of soybean paste powder. Difference amounts (0.1, 0.5 and 1 g) of soybean paste powder samples stored in normal room and darkroom conditions were measured. The PPSL signals of the soybean paste powders significantly increased with irradiation dose up to 10 kGy. The PPSL signals of irradiated soybean paste powder samples decreased with increasing storage periods. The decay rates were similar to regardless of storage conditions and sample amount. The PPSL signals of the irradiated soybean paste powder measured for 120 s were higher than those measured for 60 s. These results indicated that although the PPSL signal of all soybean paste powder samples decreased with increasing storage time, detection of irradiated samples was still possible after 12 months of storage regardless of sample amount and measurement times in both normal room and darkroom conditions.

• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.142-147
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• 2000

To establish a detection method of irradiated perilla and sesame seeds, studies were performed with pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL). The PPSL photon counts of the mineral separated from irradiated sesame and perilla seeds were higher than unirradiated one and exhibited an increase with increasing irradiation dose and mineral content. Also TL intensities of minerals separated from irradiated sesame and perilla seeds increased with increasing irradiation dose. In all samples, detection was possible with shapes and maximum TL temperatures of the second glow curves showing lower regions than those of the first glow curves and correctly classified as irradiated samples. Glow curve ratios of irradiated samples were higher than 0.5. These results suggest that PPSL and TL are applicable methods for the detection of irradiated perilla and sesame seeds.

• Preventive Nutrition and Food Science
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• 제8권1호
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• pp.79-84
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• 2003

This study was carried out to establish a method for determining if granule-type Ramen soup powder has been irradiated. Thermoluminescence (TL) and pulled photostimulated luminescence (PPSL) were used as the detection methods through observed changes of TL and PPSL intensities after storage under differing conditions. PPSL intensities increased with increases in irradiation doses. The threshold level of PPSL was below 412$\pm$58 photon counts regardless of storage conditions (room and darkroom) after 10 months. TL intensities also increased with increasing irradiation doses. The coefficients ($R^2$) of PPSL (0.74~0.94) and TL intensities (0.92~0.58) were very highly correlated with irradiation dose. The PPSL and TL intensities were decreased after 10 months of storage. These results indicate that discrimination of irradiated from non-irradiated granule-type Ramen soup powder is possible using TL and PPSL methods despite the decrease in intensities of TL and PPSL with increasing storage times.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.140-144
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• 2005

This study was carried out to establish methods for irradiation detection of irradiation in Korean wheat flour by pulsed photostimulated luminescence (PPSL) and viscometric methods. The photon counts of the irradiated Korean wheat flour measured by PPSL immediately after irradiation increased with increasing irradiation dose. The photon counts in the irradiated Korean wheat flour almost disappeared with lapse of time after storage in normal room conditions, but irradiation detection was still possible after 6 months in darkroom conditions. All irradiated samples indicated a decrease in viscosity with increasing stirring speeds (rpm) and irradiation doses. Irradiation at 1 kGy significantly decreased the viscosity. Consequently, these results suggest that the detection of irradiated Korean wheat powder is possible by both viscometric and PPSL methods.

• 한국식품과학회지
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• 제33권2호
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• pp.173-177
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• 2001

본 연구는 PPSL를 이용하여 수입 참깨와 들깨의 방사선 조사여부가 확인이 가능한지를 알아보기 위하여 수행되었다. 측정시간이 증가할수록 photon count도 증가하는 경향을 보였으며, 모든 수입 참깨 및 들깨와 여기에서 분리된 광물질의 photon count는 방사선 조사선량이 증가함에 따라 증가 하는 경향을 보여 주었으나 10 kGy에서는 5 kGy에서와 비슷하거나 약간 높은 photon count를 보였다. 참깨 와 들깨(5 g) 자체와 분리된 광물질(1㎎)로부터 측정된 photon count는 모두가 비슷한 수치를 보여 광물질에서 더 높은 photon count가 발생됨을 알 수 있었다. 또한 참깨, 들깨 자체로 측정된 시험구 보다 분리된 광물질에 대한 시험구에서 더 높은 상관성을 보여 주었다. 따라서 PPSL 측정시 참깨 및 들깨 자체를 사용하거나 분리된 광물질을 사용하여도 조사여부의 확인이 가능하였다.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.195-200
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• 2002

Changes in accumulated pulsed photostimulated luminescene (PPSL) signals were observed after storage, which affected the ability to detect irradiation in black and white peppers. The PPSL curves were accumulated linearly during the 120 s measurement times, and PPSL signals increased according to irradiation doses. Threshold levels of black and white peppers were below 557$\pm$220 and 503$\pm$92 photon counts in 60 s, and below 679$\pm$351 and 812 $\pm$ 648 photon counts in 120 s, respectively. The PPSL signals of black and white peppers linearly increased with irradiation dose up to 5 kGy, but very little from 5~10 kCy. The accumulated PPSL signals of irradiated black and white peppers had higher decay rates when stored in normal room conditions than in a darkroom Detection of irradiation was possible for up to 12 months after irradiation, if the samples were stored in a darkroom.

• Preventive Nutrition and Food Science
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• 제6권4호
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• pp.216-223
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• 2001

A study was carried out to examine the effect of sample form and storage conditions on the accumulated PPSL signals. Korean perilla and sesame seeds were tested as whole samples and separated minerals. Radiation-induced PPSL signals of perilla and sesame seeds themselves significantly increased with irradiation dose up to 5 kGy. On the other hand, a slight decrease in the accumulated PPSL signals was shown at 10 kGy. Similar results were also found in separated minerals. The accumulated PPSL signals of irradiated samples decreased with increasing storage periods. The decay rate was higher in 5 or 10 kGy-irradiated samples than in 1 kGy, in room conditions than in darkroom conditions, and in sesame and perilla seeds themselves than in separated minerals. The accumulated PPSL signals of the irradiated samples measured fur 120 s were higher than those measured for 60 s. These results indicated that although the PPSL signal of all samples decreased with increasing the storage time, detection of irradiated samples was still possible after 12 months of storage regardless of sample form and measurement times (60 and 120 s) in both room and darkroom conditions.

• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.133-137
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• 2004

This study was carried out to establish a method for the detection of irradiated glutinous rice by measuring pulsed photostimulated luminescence (PPSL) and viscometric properties. Viscosity was determined using a Brookfield DV-III rotation viscometer at 3$0^{\circ}C$ and measured at 30, 60, 90, 120, 150, 180, and 210 rpm. All irradiated samples indicated a decrease in viscosity with increasing stirring speeds (rpm) and irradiation doses. Treatments with 2∼5 kGy significantly decreased the viscosity. The photon counts of the irradiated glutinous rice were measured by PPSL and the photon counts of the non-irradiated and irradiated glutinous rice measured immediately after irradiation exhibited an increase with increasing irradiation dose. The photon counts of irradiated glutinous rice almost disappeared with the lapse of time when stored under normal room conditions, but was still possible to detect after 12 months of darkroom storage. Consequently, these results indicate that the detection of irradiated glutinous rice is possible by both viscometric and PPSL methods.

• 한국식품위생안전성학회지
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• 제16권1호
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• pp.82-87
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• 2001

본 연구는 점도 측정법과 광여기발광법을 이용하여 방사선 조사된 옥수수분말의 검지를 시도하였으며, 이전의 연구에서 수행되지 않은 다양한 rpm에서의 검지 가능성과 저장기간에 따른 광여기발광의 변화를 검토하였다. 실험에 사용된 옥수수분말은 polyethylene bag으로 포장하였고, Co-60 감마선 조사시설을 이용하여 1, 2, 3, 5, 7, 10 및 15kGy로 조사하였다. 점도측정 시료는 증류수를 가하여 현탁하고 알카리화 한 후에 RV 3 spindle이 장착된 Brookfield DV-III rotation viscometer를 이용하여 3$0^{\circ}C$에서 30초 동안 30, 60, 90, 120, 150, 180 및 210 rpm 에서 점도를 측정하였다. 광여기발광 측정은 시료(5 g)의 전처리 없이 직접 광여기발광기에 넣은 후에 측정하였다. 모든 시료의 점도는 조사선량과 stirring speeds (rpm)가 증가할수록 감소하는 경향을 보였으며, 조사선량과 점도간의 높은 상관성을 보여 주었다. 방사선 조사된 옥수수 분말의 광여기발광은 조사선량이 증가할수록 증가하는 경향을 보였고, 1개월후에도 암실조건에서의 광여기발광은 조사직후의 시험구에 비하여 감소하지 않았다. 이상의 결과를 종합하여 볼 때 점도 측정법과 광여기발광법은 방사선 조사된 옥수수분말의 조사여부를 확인할 수 있는 검지법으로의 가능성을 확인할 수 있었다.