• 제목/요약/키워드: Methanol Oxidation

검색결과 298건 처리시간 0.022초

들깨유의 산화에 대한 들깨 발아 싹 추출물의 억제효과 (Inhibitory Effect of Perilla Sprouts Extracts on Oxidation of Perilla Oil)

  • 김석중
    • 한국응용과학기술학회지
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    • 제29권2호
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    • pp.330-338
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    • 2012
  • 들깨 종자를 10일 간 발아시키면서 얻어지는 싹에 대하여 일반성분 및 항산화력의 변화를 분석하였고, 들깨유 산화에 대한 싹 추출물의 억제효과를 조사하였다. 종자의 수분 함량(2.9%)은 발아 10일째 싹에서 9.2%로 증가하였으나 조회분 함량은 유의적인 변화가 없었다. 종자에서 46.8%와 20.7%이었던 조지방과 조단백질 함량은 발아 10일째 싹에서 각각 18.2%와 18.3%로 감소하였지만, 환원당과 조섬유 함량은 2.2% 및 14.8%에서 각각 12.8%와 22.4%로 증가하였다. 깻잎과 비교하면 10일째 싹은 조지방, 탄수화물, 환원당, 조섬유 함량이 더 높았고 수분, 조회분 및 조단백질 함량은 더 낮았다. 발아동안 항산화력은 증가하여 8일째에 최대치에 도달하였는데, DPPH와 ABTS 라디칼 소거능에 기반한 Trolox 당량 항산화력(TEAC)은 각각 133.1과 136.8 Trolox eq. mmol/kg이었으며, 3가 철이온 환원력(FRAP)는 399.3 Fe(II) eq. mmol/kg이었다. 폴리페놀 함량(19.2 g/kg)도 이 단계에서 가장 높았다. 한편, 깻잎은 발아 8일째의 싹과 유사한 TEAC를 보였으나 FRAP은 더 높았다. 발아 8일째 싹의 메탄올 추출물을 들깨유에 첨가 시 농도 의존적으로 산화가 억제되었는데, 대조 들깨유에서 1.67 hr이었던 산화유도기간이 2.5%(w/w) 추출물 첨가 들깨유에서는 4.62 hr로 나타나 들깨유의 산화 안정성이 약 2.8배 증가하였다. 이러한 산화유도기간은는 동일농도의 BHT 첨가구와 비교 시 약 38% 수준에 해당하였다.

마른멸치 저장중의 수분활성과 비효소적 갈변반응 (NON-ENZYMATIC BROWNING REACTIONS IN DRIED ANCHOVY WHEN STORED AT DIFFERENT WATER ACTIVITIES)

  • 한성빈;이종호;이강호
    • 한국수산과학회지
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    • 제6권1_2호
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    • pp.37-43
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    • 1973
  • In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

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사람의 저밀도 지방단백질의 산화에 대한 생열귀나무 추출물의 항산화 효과 (Antioxidant Effect of Rosa davurica Pall Extract on Oxidation of Human Low Density Lipoprotein (LDL))

  • 사재훈;이완;신인철;정경진;심태흠;오흥석;김영진;정의호;김광기;최대성
    • 한국식품과학회지
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    • 제36권2호
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    • pp.311-316
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    • 2004
  • 비타민-C를 다량 함유하고 있는 생열귀나무의 자원화를 위한 연구로서 페놀성 화합물의 함량 및 사람의 저밀도지방단백질의 산화에 대한 항산화 활성을 측정하였다. 생열귀나무 추출물의 페놀성 화합물 함량을 측정한 결과, 모든 부위에서 100g당 8.3-10.6g으로 매우 높은 양을 함유하고 있었다. 또한, 생열귀나무 추출물 및 분획물에 대한 항산화 물질의 함량을 측정 한 결과, 생열귀나무 뿌리 메탄올 추출물과 뿌리의 에틸아세테이트 및 부탄을 분획물이 285nm에서 흡수를 나타내는 페놀성 화합물을 다량 함유하고 있음을 확인하였다. TBARS에 의한 LDL산화 억제효과 측정시, 생열귀나무 뿌리의 메탄올 추출물이 가장 좋은 효과를 나타내었다. 생열귀나무 뿌리의 에틸아세테이트 및 부탄을 분회물의 경우, $30\;{\mu}g/mL$ 첨가시 85.3% 및 93.2%까지 LDL 산화를 억제함을 확인하였다. 또한 $CHCl_3$ 분획물, EtOAc 분획물, 그리고 BuOH 분획물은 $30\;{\mu}g/mL$ 분획물 첨가시 $Cu^{2+}$에 의한 LDL 산화를 8시간까지 억제함을 확인하였다. $Cu^{2+}$에 의한 apoB carbonylation과 conjugate diene형성 억제효과 측정시, EtOAc 분획물과 BuOH 분회물이 가장 탁월하게 억제함을 보여주었다. 생열귀나무는 다량의 페놀성 화합물을 함유하고 있으며 항산화 활성이 매우 탁월하므로 새로운 기능성식품 소재로의 활용이 기대되는 약용식물자원이다.

고분자 연료전지의 전극 제조 및 성능 평가 (The fabrication of electrode and characterization of performance in the PEMFC)

  • 박인수;조용훈;최백범;정대식;조윤환;성영은
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.227-230
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    • 2005
  • There is a worldwide interest In the development and commercialization of PEMFCs for vehicular and stationary applications. The major problem in the practical use of PEMFCs is the deactivation of the Pt anode electrocatalyst by the adsorption of carbon monoxide. Therefore, intensive work has been devoted to finding electrocatalysts that are tolerant to CO in hydrogen at operating temperatures bellow $100^{\circ}C$. Also, DMFC is considered to be one of the most promising technologies for energy generation. But, the most important problem associated with the DMFC is the slow reaction rate of methanol oxidation and the second major problem is fuel crossover. So, the performance of a state-of-the-art DMFC is considerably lower than that of hydrogen-fuelled PEMFC. In this research, the preparation and characterization of electrode materials will be introduced. Also, some electrochemical techniques for the characterization of PEMFCs will be presented.

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Novel Conversion of 2-(4-Dimethylaminoaryl)-1,4-diphenylbutane-l,4-diones into 3-(4- Dimethylaminoaryl)-l-phenylpropenones via Debenzoylation and Oxidation

  • Kim, Sung-Sik;Chang, Ji-Ae;Kim, Ae-Rhan;Cho, Kyung-Won;Park, Sang-Kyu
    • Journal of Photoscience
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    • 제12권2호
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    • pp.109-111
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    • 2005
  • It was found that 1,4-diketones such as 1,4-diphenyl-l,4-butanediones containing N,N-dimethylaminophenyl (pDPB) and N,N-dimethylaminonaphthyl (nDPB) at C2 are converted into 3-(4-dimethylaminoaryl)-1-phenylpropan-lones (pPPA and nPPA) by treatment with $Ca(OH)_2$ in methanol, which was easily oxidized to enone, i.e., 3-(4-dimethylaminophenyl)-l-phenylpropenones (pPPE and nPPE), when treated with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) in dichloromethane.

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종특이 단세포군항체에 반응하는 간흡충의 당질항원 한 가지 (A carbohydrate antigen of Clonorchis sinensis recognized by a species-specific monolonal antibody)

  • 용태순;이종석
    • Parasites, Hosts and Diseases
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    • 제34권4호
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    • pp.279-282
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    • 1996
  • 간흡충 특이 단세포군항체인 CsHyb 0605-23과 반응하는 간흡충 항원의 특성을 밝히기 위하여 간흡충의 성충 조항원을 당지질 당질 단백으로 각각 분리한 후 각각 항원으로 사용하여 단세포 군항체와 효소떤역흡착검사법을 실시하였다. 그 결과. 오직 당질분획만이 단세포군항체와 반응하였다. 당질항원을 sodiumperiodate를 사용하여 약하게 산화시키자 단세포군항체와의 반응도가 떨어졌다. 따라서 이 단세포군항체에 반응하는 간흡충의 항원 및 항원결정기는 당질로 생각된다.

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Study on Hazard of Biodiesel

  • Koseki, Hiroshi;Lim, Woo-Sub;Iwata, Yusaku
    • International Journal of Safety
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    • 제11권1호
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    • pp.11-14
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    • 2012
  • Hazard of Biodiesel (BDF) was studied. Biodiesel is a name for a variety of ester-based fuel made from vegetable oils. Recently importance of biodiesel is increasing, and its fires were sometimes reported. Therefore we studied on hazard of biodiesel comparing (petroleum) diesel oil and vegetable oil, raw materials of biodiesel. We found that biodiesel is auto-oxidized easily and ignites, and its flash point decreases when even small amount of methanol exists. And there are various raw materials to manufacture biodiesel, so we studied the difference of these materials, and their aging on safety.

Determination of Higenamine in the Commercial Aconiti Tuber and Its Pharmaceutical Preparations

  • Hahn, Young-Hee;Cheong, Kyo-Soon;Paik, Seung-Whan;YunChoi, Hye-Sook
    • 생약학회지
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    • 제17권1호
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    • pp.1-6
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    • 1986
  • A cardiac principle of Aconiti tuber, higenamine was analyzed with a differential pluse voltammetry employing a glassy carbon electrode. The peak potentials for the oxidation of higenamine were varied depending on the pH of the media. Higenamine at the concentration of $5.4{\times}10^{-7}M$ (0.146ppm) was easily determined using a pH 7.0 phosphate buffer. The amounts of higenamine in the crude Aconiti tuber and tablets containing A. tuber were determined by a standard addition method after extracting with methanol, partitioning with a mixture of $H_2O$ and $CHCl_3$, and freeze-drying the aqueous layer.

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인진쑥 추출물의 항산화 및 항암 활성 (Antioxidant and Anticancer Activities of Extract from Artemisia capillaries)

  • 정미정;윤유;허성일;왕명현
    • 생약학회지
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    • 제39권3호
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    • pp.194-198
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    • 2008
  • Artemisia capillaries is a major important food and medicinal resource in Korea. In order to confirm the biological activities of Artemisia capillaries, we investigated antioxidant and anticancer activities from in vitro assays. The Artemisia capillaries methanol (MeOH) extracts was used for the evaluation of DPPH scavenging, total phenolic content, total flavonoid content, hydroxyl radical (${\bullet}OH$) scavenging, reducing power assay as antioxidant activity, as well as anticancer activities as MTT assay. As a result, the Artemisia capillaries MeOH extracts showed potent antioxidative activity and anticancer activity in vitro. These results suggest that the Artemisia capillaries MeOH extracts have a potential alleviated oxidation process, cell motility activity, and tumorigenesis.

휘발성 유기화합물(VOCs)의 촉매산화 전환에서 결합구조의 영향 및 속도특성 (Influence of VOCs Structure on Catalytic Oxidation Kinetics)

  • 이승범;윤용수;홍인권;이재동
    • 환경위생공학
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    • 제15권4호
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    • pp.44-51
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    • 2000
  • The reactivity of a range of volatile organic compounds with differing functional groups observed over 0.5% $Pt/{\gamma}-Al_2O_3$ catalyst. In general, the reactivity pattern observed was alcohols > aromatics > ketones > cycloalkane > alkanes. The deep conversion was increased as reaction temperature was increased. A correlation was found between the reactivity of the individual and the strength of the weakest C-Hbond in structure. The conversion of volatile organic compounds increases in order methanol > benzene > cyclohexane > MEK > n-hexane. That is the effect of differences in total dissociation energy. An apparent zeroth-order kinetics with respect to inlet concentration have been observed. A simple multicomponent model based on two-stage redox model made reasonably good predictions of conversion over the range of parameters studied. thus, the catalytic process was suggested as the new VOCs control technology.

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