• Korean Journal of Microbiology
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• v.43 no.2
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• pp.100-105
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• 2007

The objective of this study was to confirm biohydrogenation of linoleic acid and stearic acid production by mixed men fungi and bacteria. In mixed fungal biohydrogenation study, when linoleic acid solution was added to fungal culture (after 24 hr pre-incubation), all linoleic acids were converted to trans-11 vaccenic acid via cis-9, trans-11 conjugated linoleic acid production within 24 hr period of incubation. All linoleic acid solution was hydrogenated to trans-11 vaccenic acid within 24 hr incubation and this was continued until the end of incubation (48 hr). Both treatments (added linoleic acid solution or the same amount of solution without containing linoleic acid into fungal cultures) produced the similar amount of stearic acid. In contrast, 100% of linoleic acid solution was hydrogenated to stearic acid in mixed bacterial culture. It is concluded that the end product of mixed fungal biohydrogenation of linoleic acid is trans-11 vaccenic acid whereas mixed bacteria produced stearic acid as an end product of their biohydrogenation.

• BMB Reports
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• v.30 no.2
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• pp.138-143
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• 1997

In order to assess controversial' proposals concerning the fatty acid-induced uncoupling of mitochondrial oxidative phosphorylation, we investigated the interaction of stearic acid with key mitochondrial proteins and measured the effect of stearic acid on the respiration of cytochrome c oxidase vesicles. Electron paramagnetic resonance spectra of spin-labeled stearic acid clearly demonstrated that cytochrome c oxidase interacts strongly with stearic acid. However, the respiration of detergent-solubilized cytochrome c oxidase was not altered significantly by stearic acid. Surprisingly, adenine nucleotide carrier, which was assumed to bind and translocate fatty acid anions in the Skulachev model of uncoupling, did not bind stearic acid at all. The respiration rate of cytochrome c oxidase vesicles was increased by ~70% in the presence of $20{\mu}m$ stearic acid and this uncoupling was attributed to a simple protonophoric effect of stearic acid.

• The Korean Journal of Food And Nutrition
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• v.4 no.2
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• pp.167-174
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• 1991

In the present study, an attempt was made to Investigate the effect of stearic acid on the autoxidation of the commercial rice bran oil, Rice bran oil samples with stearic acid at 0.1, 0.3 and 0.5oh level were kept at 45$\pm$0.3$^{\circ}C$ for 40 days. The rate of autoxidation of each samples was estimated regularly on the basis of the changes of peroxide value, acid value, anisidine value and the fatty acid composition. The results were as follows : The peroxide, acid and anisidine values of the rice bran oil with the stearic acid at 0.1, 0.3 and 0.591 levels during the autoxidation Increased as compared with that of the rice bran oil without the stearic acid. The induction period of the rice bran oil without the stearic acid, control was 19.0days, while those of the bran oil with stearic acid at 0.1, 0.3 and 0.5% levels varied 19.0 days, 17.7days and 14.2 days, respectively. In conclusion, it seemed that stearic acid acted as weak prooxidant when added at 0.1, 0.3 and 0.5% levels to the commercial rice bran oil. The prooxidant activity of the stearic acid appeared to depend on the oxidative mechanism and their concentration.

• YAKHAK HOEJI
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• v.56 no.1
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• pp.14-19
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• 2012

Nonalcoholic steatohepatitis(NASH) is serious metabolic disease related to fatty acid. According to "two hit theory", fatty acid-induced oxidative stress is important factor to progress nonalcoholic steatohepatitis from steatosis. In this study, we evaluated stearic acid induced oxidative stress in human hepatocarcinoma SK-Hep-1 cell. Cell viability, reactive oxygen species (ROS) production, glutathione (GSH), malondialdehyde and expression of antioxidant enzymes were determined at various time-points and concentrations of stearic acid. At 0.2 mM, non-toxic concentration, of stearic acid, production of ROS was significantly increased at 24 hours and the level of GSH was significantly decreased. Expression of superoxide dismutase-1 and 2 was slightly increased in 0.2 mM stearic acid at 24 hours. These results represent that the non-toxic concentration of stearic acid resulted in oxidative stress, suggesting that stearic acid may play a critical role in development of steatohepatitis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.6 no.1
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• pp.49-53
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• 1977

Fatty acid composition of commercial oil were analyzed with gas liquid chromatography. Sesame, perilla, rice bran, sunflower, and soy-bean oil were obtained from the whole sale store of edible oil in market. The fatty acids were methylated with Na-methylate. The fatty acid methylester was charged to the gas liquid chromatography. Sesame were composed of myristic, palmitic, stearic. linoleic acid, and trace of linolenic acid. Rice bran, and soy-bean oil were composed of myristic, stearic, oleic, linoleic, and linolenic acid. Peilla oil was composed of palmitic, stearic, oleic, linoleic, and linolenic acid. Sunflower oil was composed of palmitic, stearic, oleic, and linoleic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.479-485
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• 2009

The acidolysis was performed to produce structured lipid with palm mid fraction (PMF) and stearic acid for 7, 24, and 36 hr at $70^{\circ}C$. The reaction was catalyzed by lipozyme TLIM (immobilized lipase from Thermonyces lanuginosa, amount of 10% and 20% by weight of total substrates) in the shaking water bath. The reaction conditions for maximum incorporation of stearic acid on the structured lipid were obtained when molar ratio of PMF and stearic acid was 1:2; concentration of lipozyme TLIM was 20wt%; reaction temperature was $70^{\circ}C$; and reaction time was 36 hr. After reaction under this condition, incorporation of stearic acid in the structured lipid was obtained up to 36.3% while the major components of triacylglycerol were 1,2-dipalmitoyl-3-stearoylglycerol (PPS, 28.19 area%), 1-palmitoyl-2-oleoyl-3-stearoylglycerol (POS/PSO, 20.70 area%) and 1-palmitoyl-2,3-distearoylglycerol (PSS, 18.13 area%). However, the fatty acid composition at the sn-2 position suggested that the positional specificity of lipozyme TLIM was not observed due to the acyl migration.

• Journal of the Korean Ceramic Society
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• v.46 no.4
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• pp.365-371
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• 2009

It is well known that the properties of concrete such as the compressive strength, water permeability, water tightness and durability are affected by micro-structure in hardened cement paste. Especially, for durability of concrete, watertightness of cementitious materials is the most critical property among various properties. Recently, many types of materials as organic and/or inorganic materials are used for watertightness of concrete. In this study, The effect of Stearic Acid at $0.5\;wt%{\sim}3.0\;wt%$ adding ratios on the hydration and watertightness property of cement were investigated. And we also discussed the changing of microstructure in hardened cement paste by addition of Stearic Acid. Cement paste with Stearic Acid showed improvement of watertightness by reducing of cement total pore volume and decomposition of Stearic Acid.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.393-396
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• 1996

The electrical characteristics of stearic acid LB films far the horizontal direction were investigated to develop the gab sensor using LB films. $\pi$ -A isotherm was measured to transfer stearic acid on slide glass substrate and surface pressure for optimal deposition was 25[dyne/cm]. The deposition status of stearic acid LB films was verified by the measurement of capacitance which was increased with the number of layers. The thickness of electrode was estimated about 1000 by the I-V characteristics far the horizontal direction. The Conductivity of stearic acid LB films for horizontal direction was 10$^{-8}$ [S/cm] that mean like semiconductor.

• The Korean Journal of Physiology
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• v.9 no.2
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• pp.1-5
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• 1975

It has been reported that kanamycin lowers osmotic fragility and mechanical fragility by ultrasonification of human red cells. In the present study, we therefore investigated effects of $Ca^{++}$, kanendomycin and kanamycin on stearic acid monolayer using a langmuir trough and found fellowing results 1) $Ca^{++}$ added to the subphase condensed stearic acid monolayer, confirming earlier reports. 2) Likewise, kanendomycin and kanamycin condensed the stearic acid monolayer, the effects being dose dependent. The possible modes of action of kanamycin and kanendomycin on biological membrane were discussed and compared with those of $Ca^{++}$ and local anesthetics

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.66-67
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• 2020

The synthesis of stearic acid composite phase change material (PCM) was investigated and the samples produced were characterized for use in latent heat storage, using a simple chemical sol-gel process. The PCM was encapsulated to tetraethyl orthosilicate by various preparation ratios of stearic acid (5, 10, 15, 20, 30 and 50%). Fourier transformation infrared spectroscope (FT-IR) and X-Ray diffraction (XRD) were performed to determine the chemical structure and crystalloid phase of the microencapsulated PCM. SATEOS1 (5%) shows the best proportion for the PCM. With the presence of stearic acid as core materials and SiO2 as the supporting materials, it does not show any chemical reaction between both of them. SATEOS1 shows promising potential for thermal energy storage as it shows a better encapsulation efficiency and good thermal stability.