• Journal of the Korean Society of Food Culture
• /
• v.18 no.2
• /
• pp.181-191
• /
• 2003

This study was carried on the oxidative stability and the real practice possibilities in cooking of fat replacer MCT. Nowadays, it was known that fats and oils had become causes for cardiac disease, obesity and cancer, so the new materials were needed for fat substitute that has less fat contents and low calories. The food industry concerned about fats and oils had been researched and developed new and various kinds of substitute fats. MCT(medium chain triglycerides) is one of the fat based fat substitutes used as fat replacers. The POV of com germ oil(CO), soybean oil(SO), shortening(ST), butter(BT), their blended oil with MCT 10-50%(w/w), and MCT were determined and oxidative stability by POV was compared MCT with those of them. MCT has shown higher oxidative stability than CO, SO, ST, BT, so oxidative stabilities in all kinds of blended oils become higher and higher by the increased substitution ratios. In case of bread, the volume of bread prepared with MCT(MCT bread) substituted for ST at 10-40% level(w/w) were increased a little comparing to that made of shortening(ST bread). But degree of gelatinization of MCT bread were a little lower than ST bread, at the substitute ratio above 40%, the degree of gelatinization were reduced greatly. These phenomena were sustained in 9 stored days. While baking losses of MCT breads were almost same as ST bread until 30% substitute ratio, and the appearances of MCT breads were similar to ST bread until 40% substitute ratio. Also rheological properties and color(Lab) of MCT breads had shown no different significantly from ST bread until 20% substitute ratio, but by the results of sensory evaluation, overall acceptance including appearance, color, flavor, taste, texture of MCT breads were recognized almost same as ST bread by panel until 40% substitute ratio. Depends on the above results, we can suggest that 30-40% of MCT will substitute for shortening in making bread in order to reduce fat and calories intake amounts.

• Journal of the Korean Applied Science and Technology
• /
• v.9 no.1
• /
• pp.47-54
• /
• 1992

The natural antioxidant such as e-tocopherol and synthetic antioxidant BHT were used to compare antioxidative effects of those antioxidants from the physico-chemical properties and fatty acid composition changes in the soybean oil due to number of frying. The composition of frying oil were consisted of a group(Fresh oil), B gorup(Fresh oil added with 0.05% ${\alpha}$-tocopherol), C group(Fresh oil added with 0.2% ${\alpha}$-tocopherol), D group(Fresh oil added with 0.1% BHT), E group(Tocopherol removed oil from oil by active alumina column chromatography The results obtained were as follws : 1. The color was determined by the Lovibond colorimeter color intensity increased number of frying oil. 2, The acid value, TBA value and Carbonyl value were increased number of frying oil. 3. Natural antioxidants less effective than BHT but effect of ${\alpha}$-tocopherol was very similar to that of BHT. 4. The order of antioxidative effect was 0.1% BHT, 0.2% ${\alpha}$-tocopherol, 0.05% ${\alpha}$-tocopherol, fresh oil, tocopherol remove oil.

• Tribology and Lubricants
• /
• v.30 no.3
• /
• pp.189-198
• /
• 2014

This paper presents the results of an experimental investigation of the correlation between the lubrication characteristics of an engine and its fuel economy. Improving the lubrication characteristics of the engine oil is one of the most efficient ways to improve a car's fuel economy. The methods to accomplish this include lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver. In addition, it is necessary to use different methods to reduce the friction to individual lubrication areas, because different lubrication regimes are used for different engine parts. The experimental investigation in this study is based on design of experiments ; this paper presents the results of a modified Sequence VID test, which is an ASTM standard test used to measure the effects of automotive engine oils on the fuel economy of passenger cars. The results demonstrate the effects of the following lubrication factors on the fuel economy : the low temperature cranking viscosity, high-temperature high shear (HTHS) viscosity, friction modifier, polymer type and shear stability index of the viscosity index improver. Moreover, this study involves an analysis of variance based on design of experiments. The test results show that the HTHS viscosity, friction modifier and shear stability index of the viscosity index improver are more effective than the other factors. Therefore, lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver should be considered to improve fuel economy.

• Korean Journal of Oriental Medicine
• /
• v.1 no.1
• /
• pp.541-553
• /
• 1995

In order to study the stability of herbal oil(Yoo-Je), the Yoo-Je from walnut and safflower measured their rancidity by gas chromatographic analysis. The use of specificity of column for estimating the oxidative deterioration of Yoo-Je was attempted. These results suggested the possible implication of pentanal and hexanal as an stability index for rancidity evaluation of Yoo-Je.

• The Korean Journal of Food And Nutrition
• /
• v.37 no.1
• /
• pp.48-56
• /
• 2024

Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

• The Korean Journal of Food And Nutrition
• /
• v.35 no.6
• /
• pp.417-425
• /
• 2022

The purpose of this study was to investigate the antioxidant activities, quality characteristics, and storage stability of perilla oil mayonnaise (PM) with different levels of onion powder (OP) from 0 to 3%. As the amount of OP increased, the L, a, and b values increased, but pH decreased (p<0.05). The addition of OP raised viscosity (p<0.05). The addition of OP to PM proportionally increased the total phenolic content, and antioxidant activities as measured by DPPH and ABTS radical scavenging activity, and FRAP assay. When compared to PM without OP, PM that contained OP had a peroxide value that was almost 1.94 times lower. The emulsion stability was between 97.62 to 94.92% in the PM without OP and PM with OP groups was 99.60% for 12 weeks. This study showed that the inclusion of OP in PM has the potential to inprove its quality, antioxidant activities, and storage stability.

• Tribology and Lubricants
• /
• v.27 no.5
• /
• pp.275-280
• /
• 2011

Automotive wheel bearing grease helps to reduce stresses and prevent wear of wheel bearings. But it is easily contaminated by water and other contaminants. In this study, we investigated the property change of automotive wheel bearing grease under water contamination. The result showed that some properties such as dropping point, work penetration and oxidation stability were not influenced by water content. However, most of properties such as work stability, water washout characteristics, leakage tendency, oil separation, evaporation loss and rust protection became worse after water was added. This is thought that added water makes the interaction weak between thickener and base oil of grease.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2015.09a
• /
• pp.93-95
• /
• 2015

In case of crude oil tanker, loading condition must be satisfied MARPOL damage stability criteria (Reg.28). But some specific demands are hard to content the criteria. So, it takes a lot of time and efforts to make loading condition reflecting these demands. In this study, PSO (Particle Swarm Optimization) is used to make loading condition to be satisfied the criteria. Study result is applied 'CROSSWAY (160,000 DWT Crude Oil Tanker)' in NAPA. The result shows that satisfy the criteria and other constraints and limitation.

• Macromolecular Research
• /
• v.17 no.2
• /
• pp.128-132
• /
• 2009

Fucoidan, a sulfated polysaccharide derived from brown seaweed, is an important material valued for its various biological functions, including anti-coagulation, anti-aging, and immune system support. In this study, we examined the potential of fucoidan as a novel emulsifying agent in BSA (bovine serum albumin)-stabilized emulsion at a neutral pH. We measured the dispersed oil-droplet size, surface zeta-potential and creaming formation of 0.5 wt% BSA emulsion (20 wt% oil traction) in the absence and presence of fucoidan. The average particle size and zeta-potential value were 625.4 nm and -30.91 mV in only BSA-stabilized emulsion and 745.2 nm and -44.2 mV in 1.0 wt% fucoidan-added BSA emulsion, respectively. This result suggested that some positive charges of the BSA molecules interacted with the negative charges of fucoidan to inhibit the flocculation among the oil droplets. The creaming rate calculated from the backscattering data measured by Turbiscan dramatically decreased in 1.0 wt% fucoidan-added BSA emulsion during storage. Accordingly, the repulsion forces induced among the oil particles coated with 1.0 wt% fucoidan in emulsion solution resulted in significantly increased emulsion stability. The turbidity of the BSA-stabilized emulsion at 500 nm decreased during five days of storage. However, the fucoidan-added BSA emulsion exhibited a higher value of turbidity than the BSA-stabilized emulsion did. In conclusion, an anionic sulfated fucoidan lowered the surface zeta-potential of BSA-coated oil droplets via the electrostatic interaction, and subsequently inhibited the flocculation among the oil droplets, thereby clearly minimizing the creaming and phase separation of the emulsion.

• YAKHAK HOEJI
• /
• v.39 no.5
• /
• pp.495-505
• /
• 1995

The O/W microemulsion systems were made from 2 or 4% (w/w) oil (soybean oil, olive oil or isopropyl myristate) and 10, 15 or 20% (w/w) Brij 96. They were compared with micellar solution of equivalent surfactant concentration m therms of physicochemical properties, and the solubilization of sudan IV. They were characterized by dynamic light scattering, stability, surface tension, viscosity and rheogram. The mean diameters of O/W microemulsion systems were 10-15nm, and those of Brij 96 micellar solutions were 18-19 nm. Both of them were monodisperse systems. The O/W microemulsion systems showed Newtonian flow and their apparent viscosities were lower than those of micellar solutions. The surface tensions of O/W microemulsion systems were increased or decreased depending on the types of oil used, when compared with those of micellar solutions. The O/W microemulsion systems were very stable, and did not show any flocculation or aggregation. Their mean diameters were not changed after three months. But oxidation was observed in microemulsions without nitrogen gas at high temperature. There was a significant improvement in the sudan IV solubffimtion in micromulsion compared with that m the micellar solution containing equivalent concentration of surfactant. The size distribution and mean diameters of O/W micromulsions were not changed when sudan IV was solubilized.