• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.131-135
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• 2000

The inhibitory effect of various organic acids on the growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract at 37$^{\circ}C$ or 4$^{\circ}C$ was determined. Minimal inhibitory pHs of acetic acid, citric acid, fumaric acid, hydrochloric acid and lactic acid were 5.0, 4.0, 4.5, 4.0 and 4.5, respectively. Acetic acid (0.012 m) showed the strongest antimicrobial activity, based on the pH values or equivalent molar concentrations, followed by lactic acid (0.0006 M), fumaric acid (0.004M) and citirc acid (0.004 M), respectively, E. coli O157:H7 with an initial inoculum of {TEX}$10^{7}${/TEX} CFU/ml and {TEX}$10^{5}{/TEX} CFU/ml in tryptic soy broth supplemented with 0.6% yeast extract, acidified to target pH with citric, fumaric and lactic acids at 37$^{\circ}C$, was completely inactivated after 7 d and 5 d incubation, respectively, except for the acetic acid (9 d). The bactericidal effect decreased at the same pH when the incubation temperature a was reduced from 37$^{\circ}C$ to 4$^{\circ}C$. The pH values of 0.2% acetic (pH 5.1), 0.6% citric (pH 4.2) and 0.4% lactic acid (pH 4.3) in TSBYE were almost correspondent to the minimal inhibitory pH values on E. coli O157:H7 of acetic (pH 4.0), citric (pH 4.0) and lactic acids (pH 4.5).

• 한국염색가공학회지
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• 제28권1호
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• pp.1-13
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• 2016

Natural colorant extracts were obtained by extraction from tumeric root, gardenia seeds, mugwort and green tea using water, methanol, ethanol and acetone as extractants at room temperature for 3 hours under shaking condition(180rpm) with liquor ratio(solid:solvent; 1:100). The main pigment components of tumeric root, gardenia seeds, mugwort and green tea are known to be curcumin, crocin, chlorophyll b and epigallocatechin gallate, respectively. The effects of the kind of extractant and pH on the color characteristics of natural colorant extracts were investigated. The solubility parameters of pigment components were determined to find adequate extractant. The solubility parameters of curcumin, crocin, chlorophyll b and epigallocatechin gallate were found to be 27.85, 29.40, 19.48 and $37.97(J/cm^3)^{1/2}$. As expected, solvents that have a solubility parameter similar to that of pigment component were generally found to be effective to obtain pigment extracts having high visible absorbance(A). The extract(pigment/solvent) with high visible absorbance was generally found to have low $L^*$(lightness) and high Chroma($C^*$, purity).

• 자원리싸이클링
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• 제22권2호
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• pp.44-52
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• 2013

코발트 정광으로부터 코발트와 구리의 회수를 위하여 3종의 Aspergillus niger 균을 이용하여 각 금속의 침출거동을 조사하였다. 주요 실험 변수로는 균주 종류에 따른 유기산 생성량, pH 및 고액농도비 등 이었다. 실험결과 유기산(구연산 및 옥살산) 생성양의 경우 A. niger KCTC 6144가 Malt Extract Broth 배지에서 초기 pH 3.5에서 가장 좋았다. 한편 코발트 및 구리 침출실험결과로는 A. niger KCTC 6985를 사용한 경우가 효과적이었는데, 고액농도 10 g/L인 경우, pH 3.5, $24^{\circ}C$에서 약 15일 경과 후 코발트의 경우는 82%, 구리는 98%의 침출율을 나타내었다.

• 한국유기농업학회지
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• 제5권2호
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• pp.117-128
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• 1997

This study was carried out to investigate the amounts of voluntary intake, digestibility and nitrogen retention in Korean native goats (KNG) fed agricultural by-products containing rice straw (RS) and apple pomace (AP) and to obtain a basic information for establishing the feeding system of KNG. The result are as follows. 1. Among the chemical composition of experimental diets, the highest values in crude protein (CP ; 18.6%) and crude ash contents (10.7%) were observed in alfalfa hay. Those of RS+AP treatment were significantly low 6.0 and 4.8%, respecitively. Acid detergent fiber (ADF), ether extract and non-structural carbohydrate (NSC) contents were shown an adverse tendency. 2. Dry matter (DM) intakes per day in KNG fed RS+commercial diet (CD), RS+AP and RS+AP+CD were significantly lower (P<0.05) 210.3, 228.3, respectively than 358.1g in alfalfa hay. 3. DM intakes per basal weight expressed as DM g/kg of BW0.75 and DM g/kg of BW(%) were highest (P<0.05) 60.5g and 3.3%, respectively in KNG fed alfalfa hay, any other treatments showed 35.6 to 42.5g and 2.0 to 2.3%, respectively and this result was similar to those of DM intake per day. 4. Digestibilities of DM, organic matter, CP, ADF, neutral detergent fiber (NDF). crude ash and ether extract in alfalfa hay and RS+AP+CD treatment were significantly higher (P<0.05) than RS+CD treatment. Those of CP, ADF and NDF of RS+AP treatment in not significantly different with these treatments. 5. NSC digestibility was higher in alfalfa hay (66.7%) than those of other treatments (44.2~52.0% ; P<0.05). 6. Nitrogen retentions expressed as N retention(g) and N retention (%) in KNG were highest (P<0.05) 0.6g and 15.6%, respectively in RS+AP+CD treatment and RS+CD treatment was lowest (P<0.05) -06g and -21.4%, respectively.

• Ocean Science Journal
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• 제40권2호
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• pp.91-100
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• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• 한국잡초학회지
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• 제14권1호
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• pp.42-48
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• 1994

수수 줄기에 함유된 타감물질의 특성을 구명하기 위해서 극성, 비극성 용매로 분획한 결과 사용한 용매에 따라 억제 효과가 달리 나타났는데 ethyl ehter 분획에서 억제작용이 가장 크게 나타났으며 또 methylene chloride와 ethyl acetate 분획에서도 8mg/ml과 16mg/ml 농도에서 상당한 억제 효과가 나타났으나 hexane과 남은 수용층 분획에서는 거의 억제 효과가 나타나지 않았다. Ethyl ether 분획을 pH에 따라 알칼리성, 중성 및 산성으로 다시 분획한 결과 산성 분획에서 억제 효과가 가장 크게 나타났다. 이상의 결과에서 수수 줄기와 함유하고 있는 타감물질은 비극성이며 산성 특성을 가진 물질이라 추측된다.

• 대한약침학회지
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• 제21권2호
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• pp.48-60
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• 2018

Objective: The aim of this study is to optimize the extraction of beneficial substance from Cudrania tricuspidata leaves grown at Jirisan Mountain in South Korea by three different solvents depending on extraction time and at different temperature. Methods: The total phenolic contents were determined by the method reported by $S{\acute{a}}nchez$-Moreno et al. The total flavonoid contents were analyzed by Slinkard and Singleton. The DPPH radical scavenging activity was determined according to the method reported by Blois Results: The extraction yield for each solvent is 9.05-14.1%, 2.17-5.67%, and 2.3-3.9% for D.W., ethanol, and hexane, respectively. The overall results were maximized for the extract obtained with D.W. for 5 min at $100^{\circ}C$. The average phenol contents were 77.11, 45.64, and 0.343 mg/g at $100^{\circ}C$ in water, $78^{\circ}C$ in ethanol, and $68^{\circ}C$ in hexane, respectively. The flavonoid contents were the highest in the materials extracted with D.W., and were increased with increasing temperature, regardless of the extraction solvents, whether water (green), polar organic ethanol, or nonpolar organic hexane. In the ethanol extract, the flavonoid contents are increased gradually from 5.66 mg/g to 7.73 mg/g. The total flavonoid contents were proportional to the concentrations of the water extracts, ranging from 4.14 mg/g to 48.89 mg/g. The antioxidative activities of the water-extracted compounds are generally increased with increasing temperature from 42.5% to 85.5%. Those of the hexane extracts are increased slowly from 3.79% to 8.8%, while those of ethanol extracts are increased from 29.8% to 47.4%. Conclusion: The extraction yields were dependent upon solvents for extraction as well as extraction time and the temperature. The optimal extraction time was 5 min and the extraction yields were increased with increasing temperature excepted hexane. Of the three tested extraction solvents, the greenest solvent of water shows excellent results, suggesting that water is among the most effective solvents for natural sample extractions for general medicinal, pharmaceutical, and food applications.

• 한국잡초학회지
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• 제17권4호
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• pp.375-381
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• 1997

볏단이 있던 곳이나 콤바인 수확한 볏짚이 피복된 곳은 잡초 발생인 생육이 감소하는 현상이 관찰되고 있다. 이는 볏짚에 함유한 allelopathic 물질에 의한 것으로 추정되어 볏짚을 80% 메칠알콜로 추출후 둑새풀로 생물검정, 10종의 표준 유기산이 둑새풀의 생육과 발아에 미치는 영향, 볏짚추출물을 silicagel column 으로 분획후 HPLC, GC/MS로 분석한 결과는 아래와 같았다. 1. HPLC분석에 의하여 볏짚에는 fumaric acid와 4종류의 미확인 유기산이 확인되었다. 2. fumaric acid를 포함한 7종의 유기산은 $10^{-2}$의 농도에서 둑새풀의 생육을 상당히 억제하였고 특히 발아를 100-90% 억제시켰다. 3. 볏짚에 함유한 물질중 억제효과가 가장 큰 것은 GC/MS분석에 의하여 II-4-4Rf 0.5에 함유한 물질로 분자량 253인 치환된 유기산인 신물질로 Octadecanoic acid, 2-oxo-, methyl ester에서 methyl ester가 유리된 물질로 추정되었다.

• 한국유기농업학회지
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• 제25권1호
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• pp.149-159
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• 2017

본 실험은 식용유와 계란노른자를 재료로 한 난황유를 이용하여 담배가루이에 대한 방제기술을 개발하기 위해 수행되었다. 파프리카의 담배가루이 약충에 난황유를 처리하였을 때, 94.5%의 높은 사충률을 보여 화학농약인 피리다벤과 유의차가 없었으나, 토마토의 담배가루이 약충에는 41.4%의 사충률로 식물추출물인 님오일보다 낮게 나타났다. 하지만 토마토에서 난황유 처리구와 님 처리구에서 성충의 사충률은 유사하였다. 난황유는 파프리카와 토마토에서 담배가루이의 산란에 각각 75.8%와 52.7%의 저해효과를 보여주었다. 친환경재배 포장에서 난황유를 2회 사용하였을 때 파프리카에서는 100%, 토마토에서는 무처리구 대비 38%의 가루이류 방제효과가 나타났다.

• Journal of Nutrition and Health
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• 제36권8호
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• pp.819-827
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• 2003

Linoleic acid [LA; 18: 2 (n-6)] is the most abundant polyunsaturated fatty acid in human skin. The exclusion of LA from diet induces epidermal hyperproliferation, which is reversible by the inclusion of LA in diet, and hence, LA is heralded as an essential fatty acid (EFA). Since safflower oil (SO) has been widely recognized as the major dietary source of LA and Arctii Fructus (Arctium lappa L.) is recently reported to contain high level of LA, we compared the antiproliferative effects of SO and Arctii Fructus in this study. Epidermal hyperproliferation was induced in guinea pigs by hydrogenated coconut oil (HCO) diet for 8 wk. During following 2 wk, EFA deficient guinea pigs were fed diets of safflower oil (group HS), water extract of Arctii Fructus (group AW) or organic extract of Arctii Fructus (group AO). Normal control group was fed SO containing diet (group SO) and EFA deficient group was fed HCO containing diet (group HCO) for 10 wk. Epidermal hyperproliferation was reversed in groups AO (55.9% of group HCO) and HS(74.1% of group HCO). However, the thymidine incorporation into epidermal DNA of group HS was greater than of normal control group SO. Epidermal hyperproliferation was not reversed in group AW. The accumulations of LA into phospholipids and ceramides, and of 13-hydroxyoctadecadienoic acid (13-HODE), the potent antiproliferative metabolite of LA in the epidermis of group AO were greater than of group HS. In contrast, the de novo synthesis of ceramides, the major lipids maintaining epidermal barrier, did not differ between all of groups. Together, our data demonstrate that organic extract of Arctii Fructus is more prominent than safflower oil in reversing epidermal hyperproliferation by inducing the higher accumulations of LA and 13-HODE in the epidermis of guinea pigs.