• 제목/요약/키워드: Oxidations

검색결과 85건 처리시간 0.032초

Antioxidant Activity of Lignan Compounds Extracted from Roasted Sesame Oil on the Oxidation of Sunflower Oil

  • Lee, Jin-Young;Kim, Moon-Jung;Choe, Eun-Ok
    • Food Science and Biotechnology
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    • 제16권6호
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    • pp.981-987
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    • 2007

  • Effects of lignan compounds (sesamol, sesamin, and sesamolin) extracted from roasted sesame oil on the autoxidation at $60^{\circ}C$ for 7 days and thermal oxidation at $180^{\circ}C$ for 10 hr of sunflower oil were studied by determining conjugated dienoic acid (CDA) contents, p-anisidine values (PAV), and fatty acid composition. Contents of lignan compounds during the oxidations were also monitored. ${\alpha}$-Tocopherol was used as a reference antioxidant. Addition of lignan compounds decreased CDA contents and PAY of the oils during oxidation at $60^{\circ}C$ or heating at $180^{\circ}C$, which indicated that sesame oil lignans lowered the autoxidation and thermal oxidation of sunflower oil. Sesamol was the most effective in decreasing CDA formation and hydroperoxide decomposition in the auto- and thermo-oxidation of oil, and its antioxidant activity was significantly higher than that of ${\alpha}$-tocopherol. Sesamol, sesamin, and sesamolin added to sunflower oil were degraded during the oxidations of oils, with the fastest degradation of sesamol. Degradation of sesamin and sesamolin during the oxidations of the oil were lower than that of ${\alpha}$-tocopherol. The results strongly indicate that the oxidative stability of sunflower oil can be improved by the addition of sesamol, sesamin, or sesamolin extracted from roasted sesame oil.

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Si(100) 기판 위에 성장된 3C-SiC 박막의 열산화에 관한 연구 (A Study on Thermal Oxidation of 3C-SiC Thin-films Grown on Si(100) Wafer)

  • 정연식;류지구;정수용;정귀상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.407-410
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    • 2002

  • Thermal oxidations of 3C-SiC thin-films grown on Si(100) by APCVD(atmospheric pressure chemical vapor deposition) were carried out. The oxidations of 3C-SiC were performed at $1100^{\circ}C$ for 1~6 hr in wet and dry $O_2$ ambient, respectively. Ellipsometry was used to determine the thickness and index of refraction of oxide films. The oxide thickness vs. the oxidation time follows the general relationship used for the thermal oxidation of Si. The surface roughness was analyzed by using AFM(atomic force microscopy). The surface roughness of oxidized 3C-SiC was rougher than before oxidation. The thermal oxide was found to be $SiO_2$ by XPS(X-ray photoelectron spectroscopy) analysis. Auger analysis showed them to be homogeneous with near stoichiometric composition.

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${\alpha}-,\;{\gamma}-Tocopherol$과 ${\gamma}-tocotrienol$의 산화 생성물 (Oxidations product of ${\alpha}-,\;{\gamma}-tocopherol$ and ${\gamma}-tocotrienol$)

  • 이형옥
    • Applied Biological Chemistry
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    • 제36권1호
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    • pp.33-37
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    • 1993

  • 유지의 자동산화과정중의 ${\alpha}-$, ${\gamma}-Tocopherol$과 ${\gamma}-tocotrienol$에 대한 주요 산화생성물로 quinone이 확인되었으며, 미량의 dimer 혹은 trimer로 추정되는 성분이 검출되었다. 생성된 quinone은 micro column을 사용하여 분취한 후 np-와 rp-HPLC로 분석하였고 MS로 동정하였다.

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