• Journal of Plant Biotechnology
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• 제7권3호
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• pp.203-209
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• 2005

This study was conducted to improve tocopherol (vitamin E) composition in soybean (Glycine max) by introducing a gamma-tocopherol methyl transferase (${\gamma}$-TMT) gene via Agrobacterium tumefaciens-mediated transformation. Immature cotyledon explants were cocultivated with Agrobacterium tumefaciens. Putative transgenic embryos were selected from immature cotyledons on MS medium supplemented with 40 mg/L 2,4-D containing 100 mg/L kanamycin, 500 mg/L carbenicillin and 250 mg/L cefotaxime. Plantlets were developed from somatic embryos, and then transferred to soil. Nineteen regenerated plantlets obtained on the selection medium from 1,460 cotyledons. However, only 9 plantlets were confirmed as transformed plants. Integration of the transgene into the soybean genomic DNA was confirmed by PCR and Southern blot analysis. HPLC analysis showed that the content of ${\alpha}$-tocopherol in transgenic soybean seeds (AT-1) was approximately 4-fold higher than that of non-transgenic plants. Conclusively, we obtained the transgenic soybean having increased ${\alpha}$-tocopherol content by the overexpression of ${\gamma}$-TMT transgene.

• Nutrition Research and Practice
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• 제7권6호
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• pp.481-487
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• 2013

High-fat diet up-regulates either insulin resistance or triglycerides, which is assumed to be related to the expression of peroxisome proliferator-activated receptor (PPAR)-${\alpha}$ and PPAR-${\gamma}$. The beneficial effects of vitamin E on insulin resistance are well known; however, it is not clear if vitamin E with a high-fat diet alters the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$. We investigated the effects of d-${\alpha}$-tocopherol supplementation on insulin sensitivity, blood lipid profiles, lipid peroxidation, and the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat (HF) diet-fed male C57BL/6J model of insulin resistance. The animals were given a regular diet (CON; 10% fat), a HF diet containing 45% fat, or a HF diet plus d-${\alpha}$-tocopherol (HF-E) for a period of 20 weeks. The results showed that the HF diet induced insulin resistance and altered the lipid profile, specifically the triglyceride (TG) and total cholesterol (TC) levels (P < 0.05). In this animal model, supplementation with d-${\alpha}$-tocopherol improved insulin resistance as well as the serum levels of TG and very-low-density lipoprotein-cholesterol (VLDL-C) (P < 0.05). Moreover, the treatment decreased the levels of malondialdehyde (MDA) in the serum and liver while increasing hepatic PPAR-${\alpha}$ expression and decreasing PPAR-${\gamma}$ expression. In conclusion, the oral administration of d-${\alpha}$-tocopherol with a high-fat diet had positive effects on insulin resistance, lipid profiles, and oxidative stress through the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat diet-fed male mice.

• 한국식품과학회지
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• 제31권1호
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• pp.252-256
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• 1999

한우육의 사태(M. Semitendinosus)를 대상으로 감마선 조사선량(0, 1, 3, 5, 10 kGy)에 따른 지질성분과 항산화 효소 활성도 및 ${\alpha}-tocopherol$ 함량의 변화를 측정하였다. 총 콜레스테롤, LDL-콜레스테롤, HDL-콜레스테롤 및 중성지질 함량에서는 비조사군과 조사군간에 유의적인 차이를 보이지 않았다(p>0.05). 항산화 효소의 활성에서 GST, catalase, SOD 역시 비조사군과 조사군간에 유의적인 차이를 보이지 않았다(p>0.05). 한편, 등심부위의 ${\alpha}-tocopherol$ 함량은 감마선 조사선량이 증가함에 따라 유의적으로 감소되었다(P<0.05).

• 한국식품과학회지
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• 제25권4호
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• pp.307-312
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• 1993

Linoleic acid methylester와 토코페놀류$({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol$과 ${\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$를 사용한 model system에서의 자동산화과정에서 온도$(40,\;60,\;80^{\circ}C)$와 산소의 양 $(0,\;10,\;20%\;O_2)$에 따르는 항산화효과를 고찰하였다. Linoleic acid methylester에서 생성된 주요 산화생성물인 13-cis/trans-, 13-trans/trans-, 9-trans/cis-, 9-trans/trans-hydroperoxide를 HPLC를 이용하여 분석하였으며, 그 양적 변화로 항산화정도를 비교하였다. 모든 토코페롤류$({\alpha}-tocotrienol$제외)는 $60^{\circ}C$ 범위에서 항산화효과가 있었다. ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$의 경우 $80^{\circ}C$ 범위에서 산화촉진효과가 관찰되었다. $40^{\circ}C$ 범위에서는 주로 cis/trans-hydroperoxide가 많이 생성되었고 $80^{\circ}C$ 범위에서는 trans/trans-hydroperoxide가 많이 생성되었다. $80^{\circ}C$ 범위의 hydroperoxide 생성량간의 오차가 심한 구간을 제외한 $40^{\circ}C/10%,\;O_2$에서부터 $60^{\circ}C/20%,\;O_2$까지의 산화구간에서 cis/trans-: trans/trans-hydroperoxides의 비율은 ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$의 순으로 고찰되어, 토코페롤류 중 ${\alpha}-tocopherol$이 가장 낮은 항산화효과가 있는 것으로 나타났다.

• Applied Biological Chemistry
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• 제35권1호
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• pp.1-5
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• 1992

한국에서 다양한 용도의 식품원료로 사용되고 있는 13개 두류의 종실에 대한 토코페롤과 지방산조성을 HPLC와 GC로 각각 분석하였다. 총 토코페롤 함량은 $4.74{\sim}44.05\;mg/100g$으로 두류에 따라 함량차이가 현저하였으며, 동족체별 토코페롤 함량은 ${\gamma}->{\delta}->{\alpha}-$토코페롤 순이었으나, 적소두 및 갈소두에서는 ${\delta}->{\gamma}->{\alpha}-$토코페롤 순이었다. 지방질 함량도 $0.53{\sim}20.96%$로 함량차가 현저하였으며, 특히 지방질 함량이 $15.78{\sim}20.96%$인 두류는 불포화지방산의 조성비가 $86.5{\sim}88.2%$로 높았고 그 중 linoleic acid가 $56.0{\sim}56.8%$로 현저하게 높았으며, 총 토코페롤 함량도 $23.2{\sim}44.05\;mg/100g$으로 높은 경향이었다. 또한 불포화지방산과 ${\gamma}$-토코페롤간에는 정의 상관관계가 인정되었다.

• Preventive Nutrition and Food Science
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• 제12권3호
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• pp.131-134
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• 2007

The kinetic analyses for thermal products of alpha-, gamma- and delta-tocopherols during heating as functions of temperature and time were studied. Alpha-, gamma- and delta-tocopherols dissolved in glycerol were heated at $100{\sim}200^{\circ}C$ for $5{\sim}60$ min. The thermal products were separated by hexane extraction and analyzed by HPLC using a reversed phase ${\mu}-Bondapak$ $C_{18}-column$ with two kinds of elution solvents in a gradient mode. The formation kinetics of thermal products of tocopherols followed a first-order kinetic model. The formation rate of thermal products of tocopherols was dependent on heating temperatures and heating times. The activation energy and enthalpy for the thermal products of ${\gamma}-and$ ${\delta}-tocopherols$ were higher than those for ${\alpha}-tocopherol$ as in the case of the oxidative degradation kinetics of tocopherol. The magnitude order of the activation energy was ${\gamma}->{\delta}->{\alpha}-tocopherol$.

• Preventive Nutrition and Food Science
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• 제12권2호
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• pp.115-118
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• 2007

Tocopherols are important lipid-phase antioxidants that are subject to heat degradation. Therefore, kinetic analyses for oxidative degradation of tocopherols as a function of temperatures and times were performed. Alpha-, gamma- and delta-tocopherols dissolved in glycerol were heated at 100${\sim}$250$^{\circ}C$ for 5～60 min. Oxidized tocopherols were analyzed by HPLC using a reversed phase ${\mu}$-Bondapak C$_{18}$-column with two kinds of elution solvent systems in a gradient mode. The degradation kinetics for tocopherols followed a first-order kinetic model. The rate of tocopherol degradation was dependent on heating temperatures. The degradation rate constants for ${\gamma}$- and ${\delta}$-tocopherols were higher than those for ${\alpha}$-tocopherol. The experimental activation energies of ${\alpha}$-, ${\gamma}$- and ${\delta}$- tocopherols were 2.51, 6.05 and 5.34 kcal/mole, respectively. The experimental activation energies for the oxidative degradation of ${\gamma}$- and ${\delta}$-tocopherols were higher than that of ${\alpha}$-tocopherol.

• 한국식품조리과학회지
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• 제27권6호
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• pp.713-721
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• 2011

Korean cabbage (Brassica campestris L.ssp.pekinensis) is one of the major cruciferous vegetables. Cruciferous vegetables contain a rare series of secondary metabolites of amino acids called glucosinolates, as well as carotenoids, tocopherol, vitamin C and fibers. This study evaluated the effect of common cooking methods (boiling, microwaving, steaming and frying) on the phytochemical content (lutein, ${\beta}$-carotene, ${\gamma}$-tocopherol, and ${\alpha}$-tocopherol), and total antioxidant capacity of Korean cabbages, determined by DPPH assay and ABTS assay. Boiling caused a decrease in carotenoids, lutein and tocopherols. Microwaving and steaming were relatively good cooking methods for maintaining lutein, ${\beta}$-carotene, ${\gamma}$-tocopherol, and ${\alpha}$-tocopherol. The overall results of this study demonstrate that some domestic cooking procedures, specifically microwave and steaming, increased the bioaccessibility of carotenoids and tocopherol, highlighting the positive role of the nutritional properties of Korean cabbage.

• 한국식품영양과학회지
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• 제25권3호
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• pp.441-452
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• 1996

The effects of chlorophyll, tocopherols($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol), carotenoids ($\beta$-carotene and lutein), light sources, light intensities and strage temperatures on the photooxidative stability of soymilk were studied by measuring TBA value and depleted headspace oxygen(DHO) of soymilk. The samples were stored in the light storage box for 6 days and evaluated for the photooxidative stabilities. As the concentrations of chlorophyll increased, TBA value and DHO of the sample increased significantly(p<0.05), indicating chlorophyll acting as a photosensitizer. However, as the concentrations of tocopherols ($\alpha$-tocopherol, ${\gamma}$-tocopherol and $\delta$-tocopherol) and carotenoids ($\beta$-carotene and lutein) increased, TBA values and DHO of the samples decreased significantly(p<0.05). The light screening effects of carotenoids on DHO in the samples were not significantly different from the control at p>0.05. Therefore, there was no light screening effects of carotenoids on the oxidative stability of soymilk. The results indicate that tocopherols and carotenoids reduce the photooxidative stability of soymilk. $\delta$-Tocopherol was the most effective in photosensitized oxidation followed by ${\gamma}$-and $\alpha$-tocopherols in the order of increasing stability. $\beta$-Carotene was significantly(p<0.05) more effective than lutein in minimizing the chlorophyll-sensitized photooxidation of soymilk. Visible light was more effective than UV light in decreasing the photooxidative stability of soymilk. Therefore, photooxidation of soymilk containing chlorophyll is mainly due to photosensitized oxidation rather than photolysis reaction. As the intensities of fluorescence light increased, TBA values and DHO of the samples increased significantly at P<0.05. However, as the storage temperatures increased, TBA values and DHO of soymilk did not change significantly at p>0.05.

• Journal of Nutrition and Health
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• 제40권8호
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• pp.708-718
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• 2007

본 연구는 비타민 E의 보충섭취가 폐경기 여성의 항산화 영양상태 및 임파구 DNA 손상을 개선할 수 있는지를 알아보고자 수행되었으며, 이중맹검법으로 실시되었고 플라시보를 위약군으로 하였다. 폐경기 여성 35명을 대상으로 6주 동안 비타민 E 보충섭취군에게는 비타민 E 캡슐($\alpha$-tocopherol 성분 400 IU/capsule)을, 위약군에게는 대두유로 만든 위약 캡슐(400 mg/capsule)을 하루 2회 섭취하도록 하였으며, 이 때 두 군의 분류는 무작위로 하였다. 항산화 영양상태를 알아보기 위해 혈장 vitamin C, $\alpha$-tocopherol, $\gamma$-tocopherol, $\alpha$-carotenoid, $\beta$-carotenoid, lycopene 농도를 측정하였고, 임파구 DNA 손상정도를 알아보기 위해서는 Comet assay를 이용하여 tail length, %DNA in tail, tail moment를 측정하였다. 비타민 E 보충섭취군에서는 혈장 vitamin C(p<0.05)와 $\alpha$-tocopherol(p<0.000)농도가 유의적으로 증가하였고, $\gamma$-tocopherol(p<0.000) 농도와 tail length(p<0.05)는 유의적으로 감소하였다. 반면, 위약군에서는 혈장 vitamin C(p<0.05)의 농도만이 유의적으로 증가하였다. 결론적으로, 본 연구는 비타민 E의 보충섭취가 혈장 항산화 상태 및 DNA 손상에 대해 부분적인 개선 효과가 있음을 보여주었다.