• Journal of the Korean Home Economics Association
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• v.29 no.4
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• pp.37-43
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• 1991

Oxidative stability of crude wheat germ oil (WGO) was determined by the active oxygen method(Rancimat, hrs at 98$^{\circ}C$). The induction time of crude WGO was 7.6hrs as compared to 23.7hrs of crude soybean oil. However, the induction time of WGO could be extended by 2-3 times with 300ppm of mixed tocopherols and 200ppm of organic acids. The antioxidant effect of organic acids increased in the order of L-ascorbic acid > tartaric acid > citric acid > malic acid. Especially, the induction time of WGO could be extended by ca. 38hrs with 500ppm of L-ascorbic acid. This antioxiative effect of 500ppm L-ascorbic acid with mixed tocopherol(100, 200, 300 or 500ppm). It seems that the synergistic effect of L-ascorbic acid was due to the high content of tocopherols(0.4%) in WGO.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.610-617
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• 2009

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey protein concentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oil because the majority of droplets were relatively small ($d_{32}=0.34$ and $0.35\;{\mu}m$, $d_{43}=0.65$ and $0.37\;{\mu}m$ for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was gradually dropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 types of emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated that WPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. It implies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.667-675
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• 2016

Nanoemulsions are actively used in several applications for pharmaceutical, cosmetic and chemical industries. In this study, we propose the use of microfluidizer known as high pressure homogenizer to prepare lipid nanoemulsion as a potent cosmetic delivery carrier. The lipid nanoemulsions were prepared by O/W emulsion with hydrogenated lecithin and different type of oils. Effects of oil type on the stability of the lipid nanoemulsion were investigated with Dynamic Light Scattering (DLS) and Zeta-potential. Arbutin was used as model drug for transdermal administration through hairless mouse skin. Transdermal arbutin delivery using the lipid nanoemulsions was studied with HPLC method.

• 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).

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.315-320
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• 2024

In order to maximize the function and increase the compatibility of silicone hydrogel lens, this study compared and analyzed the properties of Amino modified silicone oil using mini and microemulsion technique, respectively. Optical and physical properties were evaluated by spectral transmittance, refractive index, water content, oxygen transmittance and contact angle measurements to evaluate the performance of the manufactured hydrogel lens. The spectral transmittance results revealed the copolymerization method lens showed 31 % of the visible light area, which did not satisfy the basic optical properties. However, the lens using the mini and microemulsion materials showed more than 90 % of the visible light area, satisfying the optical characteristics. In addition, all physical properties were superior to a basic hydrogel lens. The mini and microemulsion techniques effectively improved the stability and function of the ophthalmic hydrogel lens and are considered a promising ways of manufacturing an ophthalmic hydrogel contact lens with increased compatibility and stability.

• Food Science and Preservation
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• v.4 no.3
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• pp.311-315
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• 1997

Proximate compositions of black rice and antioxidative effects of its methanol extract on refined perilla oil were investigated. Black rice seeds were composed of water 12.4%, crude protein 7.9%, crude fat 2.2%, crude fiber 1.0%, ash 1.4% and N-free extract 75.1%. The hexane and 80% methanol fractions in yields were higher than 80% ethanol and chloroform. In AOM(active oxygen method) test, antioxidative effects of black rice added to the refined perilla oil was increased with dose-dependent fashion in concentration of the black rice extracts. Among several extracts tested, 80% aqueous methanol extract showed the highest antioxidative activity, followed by hexane, chloroform, in that order. The peroxide value and TBA value for their antioxidation stability were also lower than that of control. This result was similar to that of AOM test.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.211-216
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• 2004

Mono-and diacylglycerol-enriched oil was produced from corn oil through enzymatic glycerolysis using 1,3-specific immobilized lipase in solvent-free system and stirred-tank batch reactor. HPLC analysis revealed enriched oil was respectively composed of: 45.05, 16.27, 23.05, and 14.98% triacylglycerol, 1,3-diacylglycerol, 1,2-diacylglycerol, and monoacylglycerol; 13.21, 0.15, 2.02, 34.36, 49.12, and 1.14 mol% palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acids; and 0.014, 0.029, 0.010 and 0.053% ${\alpha},\;{\gamma},\;{\delta}-$, and total tocopherols. Physiochemical and melting properties of enriched oil were evaluated. Oxidative stability study revealed enriched oil showed higher peroxide and p-anisidine values than corn oil. Rosemary extracts (100 to 300 ppm) reduce oxidation.

• The Journal of Fisheries Business Administration
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• v.43 no.1
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• pp.49-61
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• 2012

The tax exemption oil for fishery is expecting that the use of oil is gradually decreasing according to the environmental change such as reductions of vessel force caused by an upswing of oil prices and reduction of fishing vessels in the recent. Such reductions in the tax exemption oil amount have a negative effect on the tax exemption oil business and the fishery infrastructure. This paper studied to provide the basic data for a stable supply thorough the facts affected in the use of the tax exemption oil and the prediction for the use of the tax exemption oil in future. This analysis drew a estimation method by Cochrane-Orcutt repeated proceeding model with an object main factors such as a price of tax exemption oil and vessel force and international oil prices and exchange rates. And this analysis also drew the use of a tax exemption oil by 2000 after set up the scenario using an estimation method drawn. For the use of the estimated tax exemption oil analyzed to decrease within about 81 percent of the present(2020), It should be considering a stability plan for tax exemption oil for fishery in future.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.247-256
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• 1999

This paper describes the results of analysis, syntheses and Roll Stability of various Di-urea greases. Di-urea greases were synthesized by reaction of 4,4'-Methylenebis(phenyl isocyanate) and various amines, such as cyclohexylamine, octylamine, stearylamine and p-toluidine with base oil at 80-180 $^{\circ}C$. The synthesized di-urea greases were analyzed by FT-R spectroscopy. The Roll Stability of synthesized di-urea greases was evaluated.

• Food Science and Preservation
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• v.9 no.1
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• pp.67-73
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• 2002

In order to obtain the basal data far quality and sanitary stability of sesame oil extracted from imported sesame flours oil of whole sesame and flour sesame were investigated the proximate composition, chemical properties, fatty acid composition, sesamol, sesamolin, sesamin contents and oxidation induction period by AOM test. Moisture contents of sesame flours were less remarkably than whole sesame. There were no differences in proteins. Acid value and saponiflcation value were higher sesame flour oil than whole sesame oil. iodine value of sesame flour oil were lower than whole sesame oils. In fatty acid composition of sesame oil, contents of linolenic acid and linoleic acid were 222.44 ∼144.14 and 2713.00 ∼ 1776.46 mg/mL, respectively. And the contents of linoleic acid and γ-linoleic acid were lower sesame flour oil than whole sesame oil. The sesamol contents of sesame oil were higher whole sesame oil than sesame flour oil, sesamol content of India whole sesame oil was highest of them. The sesaminl sesamolin contents of Korean whole sesame oil were the Highest Oxidation induction periods of sesame oil by AOM were 6.76 and 13.35 In on north Korea and Chinese sesame flour oil, respectively. Therefore, it appears that oxidative stability was lower in north Korea and China sesame flour oil than in whole sesame oil group.