• Title/Summary/Keyword: Contamination Level

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The Effects of Sugar Content on Growth of Zygosaccharomyces bailii in Rice-syrup (쌀엿 저장시 주요 오염원인 Zygosaccharomyces bailii의 성장에 당도가 미치는 영향)

  • Lee, Hee-Seok;Choi, Jin-Won;Song, Hyuk-Hwan;Ha, Sang-Do;Park, Sung-Yong;Lee, Yong-Gab;Lee, Chan
    • Korean Journal of Food Science and Technology
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    • v.37 no.6
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    • pp.957-961
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    • 2005
  • Spoilage yeast was isolated from spoiled rice-syrup and identified by Microbial Identification system (MIDI) as Zygosaccharomyces bailii based on composition of fatty acids exhibiting carbon skeleton of 16:0, 16.1 $({\Delta}cis\;7)$, 18:2 $({\Delta}cis\;9)$, 18:1 $({\Delta}cis\;9)$, and 18:1. Increase in sugar content $(1^{\circ}brix)$ resulted in decreased moisture concentration (1%), and water activity decreased from 0.72 to 0,63 when sugar concentration increased from 77 to $83^{\circ}brix$. Yeast showed very slow growth during three weeks post-inoculation in rice-syrup at 17 and $79^{\circ}brix$, and maximal level of Z. bailii was found at 6 and 10 weeks storage at 15 and $25^{\circ}C$, respectively. At over $81^{\circ}brix$ its growth slowly decreased at beginning of storage, indicating rice-syrup could be preserved safely at above $81^{\circ}brix$ sugar content without Z. bailii contamination.

A Study on the Feasibility of Geomagnetic Declination Investigation at Unified Control Points in South Korea (국내 통합기준점에서 지자기 편각 조사의 타당성 연구)

  • Lee, Yong Chang
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.3
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    • pp.29-38
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    • 2016
  • As publicizing of electromagnetic devices such as smart_phone and drone etc. which are relate with geomagnetic direction, and recognition about the importance to space weather effect and their hazards rises up recently, it is required heavily that the study on the effective measurement of geomagnetic declination and geomagnetic field effects of space weather. The purpose of this study is that the investigation of the feasibility of the absolute geomagnetic measurement in a place, where man-made geomagnetic contamination is low or negligible, with replacing the azimuth marks used for the absolute geomagnetic declination measurement with unified control points(UCP) which established at suburb. Further to this, have first derived the correlation of daily variations and disturbance level between the published indices($K_P$ and $K_K$) and geomagnetic element calculated from geomagnetic data of Cheongyang observatory located at the middle stage in Korea and is a member of INTERMAGNET. In addition, have carried out that the absolute measurement for the geomagnetic declination at three places near unified control point and one place with wide open field in Korea. The world magnetic models(WMMs) are selected as the criteria for comparison on the feasibility of geomagnetic declination investigation near unified control points. We compared deviations of declination from absolute measurement with that obtained from WMMs, also those from WMMs inter-comparison. The result through examination and analysis show that the feasibility of the absolute geomagnetic declination measurement with replacing the azimuth marks with UCP which established at suburb is possible.

Comparison of Blood Metal Concentration in Ohjeok-san(Wuji-san) Treated Rats - Dose-Response Relationship and Mechanism - (오적산을 투여한 흰쥐의 혈액중 금속농도 비교에 관한 연구 - 용량-반응관계와 기전을 중심으로 -)

  • 이정렬;이선동
    • The Journal of Korean Medicine
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    • v.23 no.1
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    • pp.67-82
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    • 2002
  • Objectives: In recent years, extensive focus has been laid on adulteration of herbal medicine with heavy metals. This may be mainly due to soil contamination by environmental pollution. The objective of this study is to identify the contents of various heavy metals in the blood from Ohjeok-san (Wuji-san) Decoction (OD) treated-rats. Methods: For this study, 13 kinds of metals including essential and heavy metals, i.e. A1, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were analyzed by a slight modification of EP A methods and the following results are obtained. Results: 1. There was no significant difference between the OD-treated groups and control group in liver, kidney, bone, brain and weight, especially no significant difference at the 5th and 10th days in weight and the amount of food intake. 2. The amount of each metal analyzed in the blood were as follows; A1: 2.3~3.07 mg/l, As: 2.90~3.66 mg/l, Cd: 0~0.001 mg/l, Co: 0~0.01 mg/l, Cr: 0.40~043 mg/l, Cu: 0.93~1.88 mg/l, Fe: 414.35~464.46 mg/l, Hg: 0.01 mg/l, Mn: 0.10~0.17 mg/l, Ni: 0.01 mg/l, Pb: 0.03~012 mg/l, Se: 0.73 mg/l, Zn: 3.41~4.13 mg/l by groups, respectively. In control and experimental group, Experimental I and other experimental II, III, IV, and V groups, there were no significant differences. 3. The amount of non-toxic metals (A1, Co, Cu, Fe, Mn, Se, Zn) were $64.1{\pm}7.71{\;}mg/l$ in the control group and 60.70~67.58 mg/l in the experimental groups I, II, III, IV and V. The amount of Toxic metals (As, Cd, Cr, Ag, Pb) were $0.68{\pm}0.21{\;}mg/l$ in the control group and 0.57 ~ 0.66mg/l in the experimental groups. The total amount of metals were 32.35 mg/l in the control group and 30.48~34.12 mg/l in the test groups I, II, III, IV and V, respectively. Conclusions: There was no significant difference of metal concentration in the blood from the OD-treated-rats compared to those of the control group even if higher dosage (1~8 times the dosage for a person) of OD was administered. This may be mainly due to a decoction treatment which contains only supernatants filtered from the herb-mass after boiling. This indicates the legal limitation for metal concentration in herbal medicine must be applied according to different treatment methods of herbal medicine.

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Prediction of Pathway and Toxicity on Dechlorination of PCDDs by Linear Free Energy Relationship (다이옥신의 환원적 탈염화 분해 경로와 독성 변화예측을 위한 LFER 모델)

  • Kim, Ji-Hun;Chang, Yoon-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.2
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    • pp.125-131
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    • 2009
  • Reductive dechlorination of polychlorinated dibenzo-p-dioxins (PCDDs) and its toxicity change were predicted by the linear free energy relationship (LFER) model to assess the zero-valent iron (ZVI) and anaerobic dechlorinating bacteria (ADB) as electron donors in PCDDs dechlorination. Reductive dechlorination of PCDDs involves 256 reactions linking 76 congeners with highly variable toxicities, so is challenging to assess the overall effect of this process on the environmental impact of PCDD contamination. The Gibbs free energies of PCDDs in aqueous solution were updated to density functional theory (DFT) calculation level from thermodynamic results of literatures. All of dechlorination kinetics of PCDDs was evaluated from the linear correlation between the experimental dechlorination kinetics of PCDDs and the calculated thermodynamics of PCDDs. As a result, it was predicted that over 100 years would be taken for the complete dechlorination of octachlorinated dibenzo-p-dioxin (OCDD) to non-chlorinated compound (dibenzo-p-dioxin, DD), and the toxic equivalent quantity (TEQ) of PCDDs could increase to 10 times larger from initial TEQ with the dechlorination process. The results imply that the single reductive dechlorination using ZVI or ADB is not suitable for the treatment strategy of PCDDs contaminated soil, sediment and fly ash. This LFER approach is applicable for the prediction of dechlorination process for organohalogen compounds and for the assessment of electron donating system for treatment strategies.

Heavy Metal Concentrations in the Mollusc Gastropod, Cipangopaludina chinensis malleata from Upo Wetland Reflect the Level of Heavy Metals in the Sediments

  • Kim, Heung-Tae;Kim, Jae-Geun
    • Journal of Ecology and Environment
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    • v.29 no.5
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    • pp.453-460
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    • 2006
  • Upo wetland is the largest inland wetland in Korea as Ramsar Convention Area. The purposes of the study were to investigate the levels of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the sediment and Cipangopaludina chinensis malleata from three sites of the wetland and to assess the potential of the gastropod as a bioindicator for heavy metal levels. The gastropods were dissected into shell and soft tissue without the digestive and excretive organs. The levels of Cd, Cu and Pb were below the guideline of Soil Environment Conservation Act and the heavy metals except Cr were slightly different among the sites. Cd was higher in Upo site ($0.32{\mu}g/g$) than Sajipo site ($0.28{\mu}g/g$). Cu and Zn showed the highest value in Sajipo as $43.5{\mu}g/g\;and\;39.8{\mu}g/g$, respectively while the concentrations of Pb and Zn were the highest in Upstream as $58.8{\mu}g/g\;and\;138{\mu}g/g$, respectively. In the soft tissues and shells of the gastropod, the overall common trend in the concentrations of the heavy metals was revealed with the following order: Zn > Cu > Cr > Ni > Pb > Cd and Ni > Zn > Cr > Cu > Pb > Cd, respectively. Although the soft tissues exhibited higher concentrations of the heavy metals except Ni than the shell in the gastropod, the levels of Cd and Pb in the gastropod were generally below the restrictive values set up by Korea Food & Drug Administration. From Duncan's Multiple Range Test (DMRT) results, the concentrations of Pb and Zn in the sediments among the sites were reflected on the soft tissue (Pb) and the shell (Pb and Zn) of the gastropod in the same order. The lower value of coefficient of variation (CV) in Pb concentration of the shell than in that of the soft tissue supports the usefulness of the shell as a bioindicator for Pb pollution. Although the CV value in the shell was a little higher than in the soft tissue, DMRT results and the stability of incorporated Zn into the shell support the use of the shell of the gastropod as a potential bioindicator for long-term contamination of Zn.

Cultivar Selection for Peanut Sprouts and Investigation on the Growth Stage for the High Level of Resveratrol (땅콩나물용 품종선발과 고함량 레스베라트롤 생육단계 구명)

  • Park, Eun-Ji;Lee, Gyu-Bin;Heo, You;Son, Beung-Gu;Choi, Young-Whan;Lee, Yong-Jae;Park, Young-Hoon;Lim, Chae-Shin;Kang, Jum-Soon
    • Journal of Bio-Environment Control
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    • v.24 no.2
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    • pp.63-68
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    • 2015
  • This study was conducted to find out optimum cultivars, and growth temperature and stage in peanut sprout for resveratrol production. Morphological characteristic, days to 50% of the final germination percentage($T_{50}$) and early growth vigor were measured in 8 different peanut varieties. In result 'Jopyeong' appeared to be the most appropriate cultivar for peanut production because of its lower contamination rate, lesser lateral root formation, and thicker hypocotyl length. Optimum temperature for growing peanut sprouts was determined 27. Content of resveratrol was examined by high performance liquid chromatography(HPLC) to investigate appropriate growth stage of peanut sprouts for resveratrol production. Resveratrol was higher than $17.0{\mu}g/g$ in peanuts sprouts 9 days after plating. Considering peanut sprout's shapes and content of resveratrol into account, it was most appropriate to harvest in 9-day after germination.

Screening of DPPH radical scavenging and antimicrobial activity of extracts from local some native plants (국내 자생 식물추출물의 DPPH radical 소거활성 및 항균성 스크리닝)

  • Kim, Hyun-Soo;Ahn, Joung-Jwa;Choi, Tae-Ho;Hwang, Tae-Young
    • Food Science and Preservation
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    • v.21 no.4
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    • pp.593-599
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    • 2014
  • This study was conducted to determine the antioxidant potentials of some available plants to source alternate antioxidants and antibiotics. The antioxidant activity was evaluated by determining the antioxidant activity reducing powers and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities of extracts from some local edible native plants. The DPPH radical scavenging activity of the extracts was found to have been 0.41-94.84%. The Elsholtziasplendens NAKAI extract ($85^{\circ}C$, ethanol, accelerated solvent extraction) showed the highest level of antioxidant activity. Eight samples of plant extracts were evaluated for their antimicrobial activities against three microflora (Bacillus subtilis, Escherichia coli, and Candida albicans) using disc diffusion assay. Two samples (Geranium krameri FR. Et SAV. and Cleyera japonica Thunb.) had much more intensive antimicrobial activities than the control. However, their DPPH free radical scavenging activity levels were only 14.50 and 13.85, respectively. It is suggested that they could be used as natural preservatives against bacterial contamination in cosmetics and foods, in place of the common synthetic preservatives currently used.

Microbiological and Sensory Characteristics of Electron Beam Irradiated Squid Jeotkal and Its Ingredients (전자선 조사 양념 오징어 젓갈 및 부재료의 미생물학적 및 관능적 특성)

  • Kim, Bin-Na;Jung, Samooel;Choe, Jun-Ho;Liu, Xian De;Jo, Cheo-Run
    • Korean Journal of Agricultural Science
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    • v.35 no.2
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    • pp.155-165
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    • 2008
  • A seasoned squid Jeotkal, Korean traditional fermented seafood, and its ingredients for manufacturing, including red hot pepper powder, ground garlic, sesame seeds, were irradiated with 0, 0.5, 1, 2, and 5 kGy by electron beam and stored at $4^{\circ}C$ for 4 weeks to determine the changes in microbiological and sensory characteristics. The initial contamination of squid Jeotkal such as total aerobic bacteria, yeast & mold, and coliform bacteria were at the levels of 2.88, 3.04, and 4.20 log CFU/g, respectively. However, electron beam irradiation with does at 5 kGy reduced the total aerobic bacteria to about 1 log CFU/g. Yeast & mold and coliform bacteria were reduced to 1-2 log CFU/g after 2 kGy of irradiation and reached to undetected level when the sample was irradiated at 5 kGy and following storage at $4^{\circ}C$ for 4 weeks. Sensory characteristics showed that electron beam irradiation of up to 5 kGy did not adversely affect overall acceptability of squid Jeotkal and its ingredients during cold storage. Therefore, electron beam irradiation is one of the possible means to improve storage stability of seasoned squid jeotkal, which has limited alternative sterilization methods due to the temperature characteristics of the products.

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A Nucleic Acid Amplification Tests for Reliable HCV RNA Detection Method for Plasma-Derived Products (핵산증폭시험을 이용한 혈장분획물질에서 HCV RNA 검출)

  • Hong, Seung-Hee
    • Korean Journal of Microbiology
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    • v.44 no.4
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    • pp.293-298
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    • 2008
  • HCV is transmitted via various plasma derived products. Current methods to detect hepatitis C virus (HCV) are based on its antibody detection in the donated blood and plasma. Viral contamination can potentially escape such detection during the window period of infection, when no antibody is present or the level of antibody is too low to detect. It is trying to application of nucleic acid amplification tests (NAT) for the direct detection of HCV. The objective of this study was to develop a reliable NAT for the HCV RNA detection from plasma-derived products. The most useful primers was selected for NAT among 5 sets of primers. We have also found that QIAamp viral RNA isolation kit was the most efficient for HCV RNA isolation. The highest sensitivity and specificity was appeared in $48^{\circ}C$ annealing temperature and 30 pmol of primers. With a spiking of HCV to albumin, immunoglobulins and coagulation factors, NAT can detect up to 100 IU/ml. Meanwhile, COBAS amplicor HCV 2.0 afforded a lower sensitivity in high concentrated intramuscular immunoglobulins to below 500 IU/ml. Our results suggested that NAT appears to be a highly sensitive and specific method for HCV RNA detection in plasma-derived products.

Effect of Ozone Treatment for Safety Improvement of Fresh Vegetable Juice (녹즙의 위생화를 위한 오존처리의 효과)

  • Cho, Jae-Min;Kwon, Sang-Chul;Tu, Gi;Jeong, Jae-Hyun;Lee, Kyung-Haeng
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.612-617
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    • 2009
  • Fresh vegetable juice is a non-heat treated product and the only step to reduce microbial growth is washing. Therefore, the materials for fresh vegetable juice including Angelica keiskei, Brassica loeracea var. acephala, and Daucus carota L. were treated by ozone after the first washing process and investigated for microbial and chemical changes. The number of the total aerobic bacteria in materials after selection step were $8.2{\times}10^5{\sim}5.0{\times}10^6\;CFU/g$, which was a higher contamination level than the limit of Korea food code ($10^5\;CFU/g$). However, after the 1st washing process and ozone treatment, the total aerobic bacterial number was reduced to $4.7{\times}10^4{\sim}6.7{\times}10^4\;CFU/g$, which showed 2 log microbial reduction. After the 2nd washing step followed by ozone treatment, there was no difference in microbial number. The number of colifroms in the materials of fresh vegetable juice were $8.0{\times}10^3{\sim}3.5{\times}10^3\;CFU/g$ initially but showed $1.5{\times}10^2{\sim}3.0{\times}10^2\;CFU/g$ after the ozone treatment (1 log reduction). On the other hand, there was no changes in the contents of ascorbic acid, flavonoids, polyphenols, minerals (cadmium and lead) during all processes. In addition, no color changes were observed during washing process. Therefore, ozone treatment in the materials of fresh vegetable juice decreased the microbial numbers. Also, chemical characteristics of ozone treated sample were not different when compared with control.