• Title/Summary/Keyword: Food chain.

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Improvement of a Dynamic Food Chain Model Considering the Influence of Radioactive Contamination of Foods by Rainfall During a Nuclear Emergency (원자력 사고 중 강우에 의한 음식물 오염영향을 고려한 역동학적 섭식경로모델 개선)

  • Hwang, Won-Tae;Kim, Eun-Han;Han, Moon-Hec;Choi, Yong-Ho;Lee, Han-Soo;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.27 no.1
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    • pp.21-26
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    • 2002
  • For the consideration of the influence on radioactive contamination of foods due to rain during the release period of radionuclides in a nuclear accident, the previous dynamic food chain model was improved. Wet interception coefficients for the agricultural plants were derived as a function of radionuclide and rainfall amount, and mathematical formula of the model was also re-established. In the results for the same time-integrated radioactive concentrations on the ground, radioactive contamination of foods decreased greatly by rainfall, and it decreased dramatically according to increasing rainfall amount. It means that predictive contamination in foods using the previous dynamic food chain model, in which dry interception to the agricultural plants is only considered, can be overestimated. Among radionuclides considering in this study ($^{137}Cs,\;^{90}Sr,\;^{131}I$), influence of rainfall for food contamination was the most sensitive to $^{131}I$, and the least sensitive to $^{90}Sr$.

Structural Properties of Cold Water Extractable ${\alpha}-D-glucan$ in Rice Flours (쌀가루 냉수추출 ${\alpha}-D-glucan$의 분자구조적 특성)

  • Park, Yong-Kon;Seog, Ho-Moon;Nam, Young-Jung;Choi, Kwang-Soo
    • Korean Journal of Food Science and Technology
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    • v.22 no.6
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    • pp.603-610
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    • 1990
  • The structural properties of cold water extractable ${\alpha}-D-glucan$ in rice flours obtained by various milling methods were investigated. The blue value, ${\lambda}_{max}$ values of the iodine complex and ${\beta}-amylolysis$ limit of the cold water extractable ${\alpha}-D-glucan$ were in the range of $0.026{\sim}0.030,\;518{\sim}522\;nm$ and $52.7{\sim}59.6%$, respectively, indicating these materials were composed mainly of amylopectin-like polymer. The gel chromatography on Sepharose CL-2B indicated that the cold water extractable ${\alpha}-D-glucan$ had lower molecular weight but wider molecular weight distribution than that of the original rice amylopectin. The Sephadex G-50 gel chromatography showed that the unit chain distribution of cold water extratable ${\alpha}-D-glucan$ after debranching with pullulanase was similar to that of rice amylopectin. And the ion chromatography of the distribution pattern of the chain length below D.P.30 in the debranched ${\alpha}-D-glucan$ indicated only blade-milled flour was similar to the amylopectin, but in the amount of unit chain below D.P.10, all the ${\alpha}-D-glucan$ in rice flours was higher than that of amylopectin.

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Comparison of Upgraded Methods for Detecting Pathogenic Escherichia coli in Foods Using Centrifugation or Filtration

  • Choi, Yukyung;Lee, Heeyoung;Lee, Soomin;Kim, Sejeong;Lee, Jeeyeon;Ha, Jimyeong;Oh, Hyemin;Yoon, Yohan
    • Food Science of Animal Resources
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    • v.37 no.6
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    • pp.799-803
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    • 2017
  • In the present study, centrifugation and filtration pretreatments were evaluated to decrease sample preparation time and to improve the sensitivity and specificity of multiplex polymerase chain reaction (PCR) for the detection of low levels of pathogenic Escherichia coli in various foods. Pathogenic E. coli (E. coli NCCP11142, E. coli NCCP14037, E. coli NCCP 14038, E. coli NCCP14039, and E. coli NCCP15661) was inoculated into pork, beef, and baby leafy vegetables at 1, 2, and 3 Log CFU/g. The samples were shaken 30 times (control), then centrifuged or filtered. DNA extracts from the samples were subjected to PCR using the $Powerchek^{TM}$ Diarrheal E. coli 8-plex Detection Kit. In the pork samples, no E. coli was detected in the control samples, while E. coli were detected in 100% of 3-Log CFU/g inoculated and centrifuged samples, and in 100% of 2 and 3-Log CFU/g inoculated, and filtered samples. In the beef samples, all control samples appeared to be E. coli-negative, while E. coli was detected in 50-75% of centrifuged samples, regardless of inoculated level, and in 100% of 2 and 3-Log CFU/g inoculated, and filtered samples. In baby leafy vegetables, E. coli were not detected in 25-50% of the control samples, while E. coli were detected in 0-25% of the centrifuged samples, and 75-100% of the filtered samples, depending on the inoculum amount. In conclusion, filtration pretreatment can be used to minimize sample preparation time, and improve the sensitivity and specificity of rapid detection of pathogenic E. coli in various foods.

Simultaneous Detection of Food-borne Pathogenic Bacteria in Ready-to-eat Kimbab Using Multiplex PCR Method

  • Cho, Kye-Man;Kambiranda, Devaiah M;Kim, Seong-Weon;Math, Renukaradhya K;Lim, Woo-Jin;Hong, Su-Young;Yun, Han-Dae
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1240-1245
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    • 2008
  • Kimbab is the most popular ready-to-eat (RTE) food in Korea. A rapid detection method based on multiplex PCR technique was developed for detection of major food-borne pathogens like Salmonella spp., Shigella spp., Bacillus cereus, Listeria monocytongenes, and Staphylococcus aureus. Specific bands were obtained as 108 bp (Sau, S. aureus), 284 bp (Sal, S. enterica, S. enteritids, and S. typhmurium), 404 bp (Lmo, L. monocytogenes), 475 bp (Bce, B. cereus), and 600 bp (Shi, S. flexineri and S. sonnei). Visible cell numbers varied from 4.14-5.03, 3.61-4.47, and 4.10-5.11 log CFU/g in randomly collected June, July, and August samples, respectively. Among the 30 kimbab samples obtained 83.3% samples were contaminated and 16.7% samples were free from contamination. The highest rate of contamination was with S. aureus (56.7%) followed by B. cereus (43.3%), Salmonella spp. (36.7%), Shigella spp. (13.3%), and L. monocytogenes (6.7%). The identification of the pathogenic species could be faster using one polymerase chain reaction (PCR) and the ability to test for food-borne pathogenic species in kimbab will save time and increase the ability to assure its quality.

Exploring Quality Issues of Dairy Supply Chain and Proposing IOT-enabled Tracking Systems in Developing Country

  • Lee, Chul Ho
    • Agribusiness and Information Management
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    • v.9 no.1
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    • pp.1-6
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    • 2017
  • Recent scandals of milk additives in several developing countries provoked controversy about quality issue of dairy products, grapping academic attention to the dairy supply chain. In this paper, we first focus on moral hazard problem of self-interested entities about the quality across the dairy supply chain, due to unobservable and unverifiable quality management efforts of all entities - including dairy producers, stations, and a final producer - and high inspection cost for the quality. Based on the identified moral hazard problem, we understand why the adoption of IoT-based tracking systems about quality produced from each entity is a must, different from RFID-based tracking systems.