• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.244-245
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• 2005

Electrical insulation is one of the most important parts in a high voltage apparatus. Traditionally mineral oils and synthetic esters have been widely used as dielectric coolants for power transformers. Recently, researchers are interested in the environmental friendly vegetable oil from environmental viewpoint. This paper reports on the synthesis and characterization of soybean based ester oils. Two different types of soybean based transformer oils, named as methyl ester and isopropyl ester were synthesized. The synthesis of these esters was achieved by transesterification reactions of soybean oil and alcohol in the presence of catalyst. The GC and NMR spectroscopic analysis of the esters have been performed. The thermal stability of the esters was determined by thermal gravimetric analysis(TGA).

• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.77-81
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• 1987

No difference was observed on autoxidative stability of triacylglycerols before and after randomyl interesterification. It indicate that randomization of the glyceride composition has no significant effect on the autoxidative stability. On the other hand, the autoxidation of randomyl interesterified vegetable oil was accelerated, caused mainly by decrease of tocopherols during the series of interesterification procedures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.453-456
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• 2004

This paper surveys the latest findings on vegetable-oil-based dielectric coolants in power systems. In recent years, environmental concerns have been increased on the use of poorly biodegradable mineral oils in distribution and power transformers in regions where spills from leaks and equipment failure could contaminate the surroundings. In addition, there are demands to improve equipment efficiencies in power systems. In this reason, researches were started in the mid 1990s to develop a fully biodegradable dielectric coolants. Vegetable oil was considered the most likely candidate for a fully biodegradable dielectric coolants. Vegetable-oil-based dielectric coolants provide the advantages of high level of biodegradability, renewable natural resource, non-toxic properties, enhanced fire safety, more effective cooling and good dielectric strength for many electrical equipment.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.265-273
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• 2012

The purpose of this study was to determine the effects of the duration of frying and storage periods on physicochemical characteristics of various oils using at home. The materials used for the study consisted of four kinds of vegetable oils: soybean, canola, extra virgin olive and pure olive oils, and shortening. Chicken breasts were fried in oils heated at $180^{\circ}C$. The oils were stored with or without filtering and reused 3 times, during the 10 day period. The extra virgin and pure olive oils showed higher acid, peroxide value and yellowness than the other oils (p<0.05), but soybean oil showed the highest increase in acid, peroxide value and yellowness with reusing and storage. In sensory evaluation, the chicken breast fried with soybean oils remarkably decreased the overall acceptance. These results suggested that all frying oils are available because acid and peroxide values of the oils are lower than the standard level. However, reusing soybean oil should be noted with caution in that it is very easy to reduce rancidity, and extra virgin olive oil is not appropriate for frying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.736-742
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• 1994

This study was designed to observe the effects of the mixed diets of edible mushrooms and vegetables oils on the lipid component and fatty acid composition in liver of the diet induced hydpercholesterolemic rats. Ten groups of male S.D. rats were fed a basal diet supplemented with 5% of one of three mushrooms(G.I, L.e, A.j) and 10% of one of three vegetable oils (olive ,safflower perilla) for three weeks. In liver, total cholesterol concentration was significantly low in group 3 (olive oil 10 % + L. edodes 5%) and 6 (safflower oil 10 % $_2$L. edodes 5%) , triglyceride concentration was low in groups 8 (perilla oil 10 % + g. lucidum 5%) and 9 (perilla oil 10% + L. edodes 5%) and phospholipid concentration was significantly low in groups 3, 5, (safflower oil 10 % + G.lucidum 5%), 6, 7 (safflower oil 10 % + A .judae 5%) 8, 9 and 10 (perilla oil 10% + a. judae 5%). in the fatty acid composition of total lipid inliver, monounsaturated fatty acid (MUFA) concentration s were high in groups 2 (olive oil 105 + g. lucidum 5%), 3, and 4 (olive oil 10% + A. judae 5%) and all the perilla oil groups, polyunsaturated fatty acid (PUFA) and linoleic aicd concentrations were signifciantly high in all the safflower oil groups. In the fatty acid composition of liver phospholipid , PUFA concentrations were ghih but MUFA concentrations were low. In the triglyceride component, MUFA were some more than saturated fatty acid (SFA) . In the cholesteryl ester component, MUFa concentrations were significantly high. In the fatty acid composition of liver lipid components, linholeic acid was high in the PUFA and so it was major fatty acid. Eicosapentaenoic acid (EPA) of phospholipid component in liver was significantly high.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2583-2589
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• 2014

Background: Soybean oil may protect against cancer of the breast and prostate. It may also exert beneficial influence in combination with other oils. Here, blends (20%, v/v) of sea buckthorn oil (SEBO), camellia oil (CAO), rice bran oil (RBO), sesame oil (SEO) and peanut oil (PEO) with soybean oil (SBO) were formulated. Materials and Methods: Oxidative stability (OS) and radical scavenging activity (RSA) of SBO and blends stored under oxidative conditions ($60^{\circ}C$) for 24 days were studied. By blending with different kinds oils, levels of polyunsaturated fatty acids (PUFA) decreased, while monounsaturated fatty acid (MUFA) content increased. Progression of oxidation was followed by measuring peroxide value (PV), p-anisidine (PAV), conjugated dienes (CD) and conjugated trienes (CT). Results: Inverse relationships were noted between PV and OS at termination of storage. Levels of CD and CT in SBO, and blends, increased with increase in time. The impact of SEO as additives on SBO oxidation was the strongest followed by RBO, CAO, SEBO and PNO. Conclusions: Oxidative stability of oil blends was better than SBO, most likely as a consequence of changes in fatty acids and tocopherols' profile, and minor bioactive lipids found in selected oils. The results suggest that these oil blends could contribute as sources of important antioxidant related to the prevention of chronic diseases associated to oxidative stress, such as in cancer and coronary artery disease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.232-238
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• 1988

As a part of the studies on effective utilization of polyunsaturated lipids in sardine (Sardinops melanosticta), when the refined sardine oil was mixed with soybean and other vegetable oils storage stability and the effect to the quality of the product was investigated. Addition of 1 volume of refined sardine oil to 4 volumes of soybean oil was recommended to yield 3 in P/S ratio and 1.5g of eicosapentaenoic and docosahexaenoic acid per 40g of the mixed oil for a good storage stability and as a dietary source of EPA requirement for atherosclerotic disease. When the unpurified vegetable oils, sesame oil and perilla oil, were mixed with the same volume of refined sardine oil the content of n-3 fatty acids was increased to $13.36\%\;and\;30.65\%\;%\;from\;0.27\%$ in sesame oil and $29.72\%$ in perilla oil. The n-3/n-6 ratios were also raised to 0.476 and 1.433 from 0.006 and 0.876. And these mixed oils were more stabilized than the refined sardine oil during storage at $30^{\circ}C$.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1064-1067
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• 2012

Recently, there is a growing interest in vegetable oils, cheap and abundant renewable natural resources. Vegetable oils can be used as raw materials for ecofriendly biodegradable polymer materials. In this study, poly(${\beta}$-amino esters) were synthesized by polymerization reaction of acrylated epoxidized soybean oil (AESO) and 2-aminoethanol. Various polymer films were prepared by changing the molar ratio of AESO to 2-aminoethanol. The formation of C-N bonds in poly(${\beta}$-amino ester) was confirmed using FT-IR. Gel contents higher than 98% confirmed the synthesis of crosslinked polymer networks. Tensile strengths and elongation at breaks of polymer films ranged from 0.3 to 1.3 MPa and 32 to 55%, respectively. Polymer films degraded 2 to 7% of the initial weight in 35 days in phosphate buffer solution (pH 7.2) containing lipase enzyme.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.176-184
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• 1998

A total of 125 pigs (5.8 kg of BW) were allotted in a completely randomized block design. Treatments were coconut oil, corn oil, soybean oil, tallow and tallow+lecithin. Each treatment had 5 replicates with 5 pigs per replicate. From d 0 to 7, pigs fed vegetable oil supported greater average daily gain (ADG) and improved feed/gain (F/G) compared to pigs fed the animal fat. Addition of lecithin to tallow increased ADG by 7.2%. Feed intake were similar for all treatment groups. From d 8 to 14, pigs fed coconut oil and soy oil showed better ADG and average daily feed intake (ADFI) than any of the others. From d 15 to 21, pigs fed the tallow diets had lower gains (p < 0.05) than those fed diets that contained vegetable oil and tallow with added lecithin. The effect of different fat sources on gain became smaller with age. Feed intakes were similar between the vegetable oil and lecithin supplemented diets each week postweaning except for pigs fed tallow (p < 0.05). Feed : gain ratios were superior during the initial 2 weeks postweaning period when pigs were provided vegetable oil diet compared with pigs fed tallow. All pig groups had similar feed : gain ratios during 3 weeks. Combinations of tallow with lecithin tended to have intermediate feed/gain ratio. It was found that vegetable oils were much better in improving growth rate of the piglets. Lecithin significantly improved growth rate and feed efficiency of the pigs through the whole experimental period compared to tallow. Coconut oil was the most effective in improving growth of pigs during the first two weeks postweaning. Corn oil had equal value with soy oil in improving growth performance of weaned pigs. When vegetable oil was added, the digestibilities of nutrients except for minerals were higher than when the tallow was fed. Nutrients digestibility was similar among vegetable oils. The addition of lecithin to tallow increased digestibility of gross energy, dry matter, ether extract and crude protein. Crude ash and phosphorus digestibility were not affected by the treatments. Dry matter excretion was not different among treatments except for tallow which showed significantly higher dry matter excretion (p < 0.05), while nitrogen excretion was significantly decreased in pigs fed vegetable oil sources. However, Phosphorus excretion was not affected by the different fat sources.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2769-2773
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• 2014

In this work, a new family of polyhedral oligomeric silsesquioxanes (POSS) based esters have been synthesized that consists eight ester functional groups. These are classified into Type-I and Type-II esters based on the starting materials, octakis(3-chloropropyl)silsesquioxane (Cl-POSS) and octakis(3-hydroxypropyldimethylsiloxy) octasilsesquioxane (OHPS) respectively. These new POSS type ester moieties can be used as insulating oils and oil additives in the transformers and also considered to be alternatives to mineral and vegetable oils that are presently used in the insulation system.