• Journal of the Korean Home Economics Association
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• v.11 no.2
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• pp.139-146
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• 1973

The level of serum cholesterol was successively determined for 4 weeks after the basic diet feeding for 8 weeks in the rabbits. It was observed that the individual serum cholesterol levels were highly elevated by the oral administration of cholesterol for 18 days, and then the rabbit were fed by sesame and rape seed oils for 11 weeks to survey the effect of the oils which was playing a role of decreasing factor for serum cholesterol values. The results were obtained as follows ; 1. The rabbit's serum cholesterol level was 128±29.0mg/dl in average, it was higher in female (162±50.6) than male(95±17.6). 2. It can be possible elevating experimentally the level of serum cholesterol by the cholesterol administration per os. 3. There were significant effect of the vegetable oils to decrease the experimental hypercholesteremia in the rabbits.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.527-530
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• 2003

• Toxicological Research
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• v.31 no.3
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• pp.307-312
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• 2015

Trans fat is a unsaturated fatty acid with trans configuration and separated double bonds. Analytical methods have been introduced to analyze trans fat content in foods including infrared (IR) spectroscopy, gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, reverses-phase silver ion high performance liquid chromatography, and silver nitrate thin layer chromatography. Currently, FT-IR spectroscopy and GC are mostly used methods. Trans fat content in 6 vegetable oils were analyzed and processing effects including baking, stir-frying, pan-frying, and frying on the formation of trans fat in corn oil was evaluated by GC. Among tested vegetable oils, corn oil has 0.25 g trans fat/100 g, whereas other oils including rapeseed, soybean, olive, perilla, and sesame oils did not have detectable amount of trans fat content. Among cooking methods, stir-frying increased trans fat in corn oil whereas baking, pan-frying, and frying procedures did not make changes in trans fat content compared to untreated corn oils. However, the trans fat content was so low and food label can be declared as '0' trans based on the regulation of Ministry of Food ad Drug Safety (MFDS) (< 2 g/100 g edible oil).

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.133-137
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• 2007

The 2,2-diphenyl picrylhydrazyl (DPPH) method, which can be used to predict the oxidative stability of edible oils, was previously reported by our research group. Not only free radical scavenging antioxidants but also radicals from oxidized oils are capable of reacting with DPPH radicals, thereby reducing the absorbance of DPPH. In this study, the optimum sample size of edible oils for the DPPH method was determined, and the oxidation of the edible oils was monitored via DPPH, coupled with other conventional methods. The optimum sample size was determined as 1.5 g using soybean oil. Soybean, corn, virgin olive, and refined olive oils were thermally oxidized for 3 hr at $180^{\circ}C$ and analyzed via DPPH, conjugated dienoic acid (CDA) value, and p-anisidine value (p-AV) protocols. Soybean and corn oils were found to be more sensitive to thermal oxidation than virgin and refined olive oils, on the basis of the CDA value and p-AV measurements. The DPPH method can indicate the inherent radical scavenging activity of unoxidized samples, the time required for the depletion of antioxidants, and the rate of degradation of the antioxidants. The soybean and corn oils evidenced higher levels of free radical scavenging compounds, required more time for the consumption of inherent antioxidants, and also manifested steeper antioxidant degradation rates than olive oils, based on the results of DPPH analysis. The DPPH method, accompanied by other conventional methods, may prove useful in predicting the degree of oxidation of vegetable oils.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.385-390
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• 2010

Transesterifications of vegetable oils (soybean oil, grapeseed oil, corn oil, canola oil) by ultrasonic energy were examined on various catalysts for biodiesel production. Reaction activities of the transesterifications were evaluated to the ultrasonic energy and thermal energy. The physicochemical properties and product distribution were also investigated to the biodiesels produced from the oils in the reaction using ultrasonic energy. The yields of fatty acid methyl ester (FAME) on the alkali catalysts were higher than those on the acid catalysts. The highest FAME yield was obtained as 83% on potassium hydroxide catalyst in the transesterification. The effective reaction conditions by ultrasonic energy were 1 wt% catalyst loading and 6:1 molar ratio of methanol to vegetable oils. The reaction rate of the transesterification by ultrasonic energy was faster than that by thermal energy. The acid values of the biodiesel products were improved above 30% compared to those of the feedstocks.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.6
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• pp.48-53
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• 1988

In a previous report, the properties of vegetable oils as diesel fuel substitutes were investigated and the basic load performance of a diesel engine was examined using vegetable oil. The results show that despite of the long term chain hydrocarbon structure and large droplet size due to high viscosity, vegetable oils have good basic performance and exhaust emissions, however they cause serious problems as carbon deposit buildup, they have poor durability, and also poor thermal efficiency. In this paper, the startability and engine durability with long term operation was tested by physical methods for reducing viscosity when vegetable oil was used as compared against diesel fuel. The results obtained in this investigation may be stated as follows; (1) There is no problem in startability when vegetable oil was used as diesel fuel substitutes as far as fuel temperature is higher than 30.deg. C (2) The carbon deposits were most extensive at lower loads and lower engine speeds, and deposit buildup more heavily on the cooler parts of the combustion chamber wall. (3) Blends with 25% diesel fuel and 20v-% ethanol are effective in reducing the carbon deposit buildups. (4) Significant improvement in carbon deposit and piston ring stick can be obtained by heating fuel(200.deg.).

• Food Science and Biotechnology
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• v.15 no.2
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• pp.183-188
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• 2006

The tocopherol and tocotrienol contents of 39 vegetable oils, margarines, butters, and peanut butters typically consumed in the Korea diet were determined by direct solvent extraction method followed by normal phase liquid chromatography. All samples were locally obtained in the Cheongju area in 2003 and 2004. The study examined data on 19 vegetable oils, 10 margarines, 6 butters, and 4 peanut butters. ${\gamma}$-Tocopherol (${\gamma}$-T) and ${\alpha}$-tocopherol (${\alpha}$-T) were detectable in all products except butters and were usually present in the vitamin E form in greater quantity than the other isomers. Usually, ${\gamma}$-T content was higher than ${\alpha}$-T content in many samples. Tocotrienols were measurable in some samples but usually at levels less than the corresponding tocopherols. Three analytical method validation parameters, accuracy, precision, and specificity, were calculated to ensure the method's validity and were all confirmed to be reliable and satisfactory.

• Food Engineering Progress
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• v.21 no.1
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• pp.49-56
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• 2017

Vegetable seed oils (VSOs) have been extracted and used not only as ingredients in food and as sources of dietary lipids, but also as sources of nutraceuticals used to overcome the various oxidative stresses that contribute to the development of diseases, including cancer and other chronic conditions. The chemical compositions and oxidative stabilities of various VSOs were therefore investigated; samples were stored for 35 d, with each oil having been tested under $O_2$ exposure, sealed from $O_2$ exposure and sealed from $O_2$ exposure while containing $O_2$ scavengers. Oxidative stability was evaluated by peroxide value (POV), p-anisidine value (p-AnV), iodine value (IV), and thiobarbituric acid (TBA) value. Perilla seed and flaxseed oil were mostly composed of linolenic acid (45.5% and 59.7%, respectively), whereas pine seed oil was mostly composed of linoleic acid (48.3%). Meanwhile, camellia seed and olive oils contained 80% oleic acid, which correlated strongly with oxidative stability. The POV, p-AnV, and TBA values were the highest under $O_2$ exposure, and the lowest in the presence of $O_2$ scavengers. These results indicate that VOS oxidative stability depends not only on storage conditions, but on unsaturated fatty acid profiles as well.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.980-983
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• 1999

The contents of sterols and stanols in vegetable oils and mist oil were analyzed by gas chromatography using a capillary column. The total sterol contents showed high values of 0.67~0.89g/100g in corn oil, rice bran oil, red pepper seed oil and sesame oil. Mist oil, a byproduct of soybean oil manufacture, was a suitable raw material for the production of stanol since it showed high sterol content (10.2g/100g). In the hydrogenation of sterol contained in mist oil using Pd catalyst, the effects saponification of oil were examined. The conversion of sterol to stanol was improved by a factor of 4~5 through saponification of oil, compared to the reaction without saponification.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.688-691
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• 2004

Concentrations of PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene] in vegetable oils and fats available in Korean market were estimated. Involved methodology were liquid-liquid partition, purification on Sep-Pak Florisil Cartridges, and high performance liquid chromatography using fluorescence detector. Overall recoveries for eight PAHs spiked into vegetable oils and fats ranged from 68.2 to 101.5%, averaging 85.4%. Mean levels of benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene in vegetable oils and fats were 0.53, 0.82, 0.50, 0.18, 0.35, 0.16, 0.31, and $0.44{\mu}g/kg$, respectively.