• Korean Chemical Engineering Research
• /
• v.52 no.2
• /
• pp.219-225
• /
• 2014

In this study, effect of cosurfactant on the solubilization rate of n-octane, n-decane and n-dodecane oil was performed by micellar solutions of polymeric nonionic surfactant Pluronic L64($EO_{13}PO_{30}EO_{13}$) at room temperature. It has been found that the solubilization rate of a hydrocarbon oil was enhanced with an increase in both chain length and amount of alcohol added. In case of addition of a short chain alcohol such as 1-butanol, the solubilization rate of a hydrocarbon oil was slightly increased since most of alcohol molecules remained in an aqueous surfactant solution. On the other hand, the addition of a relatively long chain alcohol such as 1-hexanol and 1-octanol produced a big increase in solubilization rate of a hydrocarbon oil mainly due to incorporation of alcohol molecules into micelles and thus producing more flexible micellar packing density. Dynamic interfacial tension measurements showed the same trend found in solubilization rate measurement. Both interfacial tension value at equilibrium and time required to reach equilibrium decreased with an increase in chain length of an alcohol.

• The Korean Journal of Pharmacology
• /
• v.29 no.1
• /
• pp.157-163
• /
• 1993

Intramolecular excimer formation with the fluorescent probe 1,3-di(1-pyrenyl)propane (Py-3-Py) was used to investigate the effects of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol and 1-decanol on the lateral diffusion of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV). The n-alkanols increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMV. In a dose-dependent manner, n-alkanols increased lateral diffusion of hydrocarbon region of bulk (inner+outer monolayers) SPMV lipid bilayers, and the potencies of n-alkanols up to l-nonanol increased with carbon chain length. It appears that the potencies in bilayer fluidization due to the lateral diffusion increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.1372-1377
• /
• 2009

For the remediation of the subsurface contaminated by nonaqueous phase liquids(NAPLs), it is important to characterize the NAPL zone properly. Conventional characterization methods provide data at discrete points. To overcome the weak points of conventional characterization methods, the partitioning tracer method has been developed and studied. The average saturation of NAPL($S_n$), which is the representative and continuous saturation value within contaminated site, can be calculated by comparing the transport of the partitioning tracers to that of the conservative tracer in the partitioning tracer method. In this study, the application of the partitioning tracer method in heterogeneous media was investigated. To represent the heterogeneous condition of subsurface, a two-dimensional soil box was divided into four layers and each layer contained different sized soils. Soils in the soil box were contaminated by the mixture of kerosene and diesel, and partitioning tracer tests were conducted before and after the contamination using methanol as conservative tracer and 4-methyl-2-pentanol, 2-ethyl-1-butanol, and hexanol as partitioning tracers. The response curves of partitioning tracers from contaminated soils were separated and retarded in comparison with those from non-contaminated soils. The contamination of soils by NAPLs, therefore, can be detected by partitioning tracer method considering these retardations of tracers. From our experiment condition, the average saturation of NAPLs calculated by partitioning tracer method using the methanol as conservative tracer and hexanol as partitioning tracer showed the highest accuracy, though all results were underestimated. Further studies, therefore, were needed for improving the accuracy using the partitioning tracer test in heterogeneous media.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.2
• /
• pp.277-288
• /
• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.

• Journal of the Korean Chemical Society
• /
• v.42 no.4
• /
• pp.383-390
• /
• 1998

The interaction of phenoxide anion with several cationic surfactant micelles (DTAB, TTAB, CTAB, CDEAB, and CTAC) was studied by UV/Vis spectrophotometric method. The solubilization constants of phenoxide anion into the cationic micellar phase and the critical micelle concentration of these surfactants in the presence of the phenoxide anion could be determined from the absorbance changes. The measured solubilization constants were changed according to the following order: $K_s(CTAC)>K_s(CDEAB)>K_s(CTAB)>K_s(TTAB)>K_s(DTAB).$ Effects of salts(NaCl and NaBr) and n-alcohols(butanol, pentanol, and hexanol) on the solubilization of phenoxide anion by the TTAB system have been also measured and analyzed. There was a great decrease of solubilization constant and CMC with these additives. The standard Gibbs free energy, enthalpy, and entropy changes for the solubilization of phenoxide anion by the TTAB system were calculated from the temperature dependence of $K_s$ values.

• Korean Journal of Food Science and Technology
• /
• v.28 no.2
• /
• pp.330-336
• /
• 1996

Quality characteristics of mash of takju prepared by different raw materials such at nonglutinous rice. glutinous rice, barley and wheat flour were investigated during fermentation. At the beginning stage of fermentation, ethanol content was in the range of $0{\sim}1.2%$ but it was increased to $9.8{\sim}11.6%$ after 16 day of fermentation. takju that was made of nonglutious rice with starter showed higher ethanol content than any other treatment. At the first stage, pH of takju that was made of nonglutinous rice without starter was 6.57 while other sample showed pH $5.04{\sim}5.80.$ There was no significant difference in pH value between treatments after 2 day of fermentation. Total acid was increased rapidly at the first stage of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without addition starer showed higher total acid content than the other teratments. Total sugar contents were $19.18{\sim}20.23%$ at the beginning of fermentation, and decreased to $5.21{\sim}14.03%$ after 2-4 days of fermentation. Takju that was made of wheat flour showed higher value of total sugar during the fermentation. Reducing sugar contents of takju decreased with fermentation progressing to $0.2{\sim}0.5%$ after 16 day if fermentation. L value decreased during the fermentation. period and that of takju that was made of barley had lowest L value among the treatment. Alcohols, such as n-propanol ($nd{\sim}0.05\;mg/ml$), iso-butanol (0.02), iso-amyl alcohol ($nd{\sim}0.13$), n-hexanol ($nd{\sim}0.17$), n-heptanol ($nd{\sim}0.09$), and phenylethanol ($nd{\sim}0.02$) were detected. There were no alcohols detected at the beginning of fermentation, but their contents were increased during fermentation.

• Korean Journal of Food Science and Technology
• /
• v.32 no.5
• /
• pp.1015-1021
• /
• 2000

Volatile flavor components (VFCs) in cooked black rices (Suwon-415 and Chindo) were studied. The major reactions during cooking, which result in aroma volatiles, are the Maillard reaction between amino acids and reducing sugars, and thermal degradation of lipid. Black rices washed with water were soaked in 1.5 folds water and heated at $110^{\circ}C$ in oil bath for 30min. VFCs in cooked black rices were extracted for three hours by SDE and were analyzed by GC and GC/MS. A total of 91, 82 volatiles were identified in Suwon-415 and Chindo black rice, respectively. Suwon-415 was composed of 26 alcohols, 10 aldehydes, 5 acids, 11 esters, 15 ketones, 9 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 9 sulfur containing compounds. Chindo was composed of 28 alcohols, 9 aldehydes, 4 acids, 12 esters, 14 ketones, 5 hydrocarbons, 3 furans, 3 nitrogen containing compounds and 4 sulfur containing compounds.

• Microbiology and Biotechnology Letters
• /
• v.27 no.6
• /
• pp.491-499
• /
• 1999

A great variety of the volatile metabolic by-products was formed in yeast cell during alcohol fermentation. The seibel grape (Vitis labrasca) which was grown in the Southern Korea used for wines. The objective of this research was to identify the volatile flavor compounds during alcohol fermentation and aging at 12$^{\circ}C$. saccharomyces cerevisiae and Schizosaccharomyces pombe were inoculated and fermented in seibel grape must. The volatile flavor compounds of logarithmic, stationary and death phases were extracted, concentrated and identified by gas chromatography/mass spectrometer (GC/MS). The volatile flavor compounds were determined by a Hewlett-Packard 5890 II Plus GC which was equipped with Supelcowax 10 fused silica capillary column (60m$\times$0.32mm$\times$0.25${\mu}{\textrm}{m}$ film thickness) wall coated with polyethyleneglycerol. The scan detection method allowed the comparison of the spectrum from the chromatogram of volatile flavor compounds to those in data Wileynbs base library. Among the volatile compounds collected by ether-hexane extraction method, the evolution of 20 main compounds, such as 9 esters (ethyl butyrate, isoamyl acetate, ethyl caproate, n-hexyl acetate, ethl caprylate, ethyl caprate, diethy succinate, ethyl hexadecanoate, 2-pheneethyl acetate), 4 alcohols (3-methyl-1-butanol, 1-hexanol, 1-heptanol, benzoethanol), 4 ketones and acids (2-octanone, caproic acid, caprylic acid, capric acid), 2 furan and phenol (2,6-bis(1,1-dimethyl ethyl)phenol, 2,3-dihydrobenzofuran) were observed during alcohol fermentation and aging. The production of the esters during alcohol fermentation with S. cerevisiae was higher than those of Sch. pombe. The sensory scores of the aged wine samples in aroma, taste and overall acceptability were not significantly different(p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.738-746
• /
• 2006

Aroma compounds in four different Byeolmijang made from optional ingredient addition were extracted by SDE (simultaneous steam distillation extraction) and analyzed with GC (gas chromatography) and GC/MS (mass-spectrometry). The major aroma compounds in the four different Byeolmijang during aging were 1-octene-3-ol, hexanal, benzeneacetaldehyde, benzaldehyde, fufural, pyrazine, furan and phenol type compounds. Generally, benzeneacetaldehyde, benzaldehyde, fufural and phenol type compounds were increased during aging. On the other hand, 1-octen-3-ol, hexanal and furan were decreased during aging. Furfural, 2-furanmathanol and benzeneacetaldehyde in Sanghwangjang, 3-methyl-1-butanol, phenol and 1H-indole in Mujang, hexanal, 1-octen-3-ol and 2,4-decadienal in Bizijang and hexanal, tetramethylpyrazine and 2-methoxy-4-vinylphenol in Jigeumjang were identified as major aroma compounds, respectively. Generally, the major aroma compound in four different Byeolmijang with optional ingredient was similar with control and pyrazine, furan and phenol type compounds were decreased to addition with optional ingredient. The major aroma compound in Sanghwangjang with optional ingredient (onion) were 1-hexanol and 2,5-dimethylthiophene and the major aroma compounds were 1,2,4-trithiolane and 2-buthyl-2-octenal in Mujang with optional ingredient (Letinus edodes). Furfural, benzaldehyde, benzeneacetaldehyde, 1,2,4-trithiolane and lenthionine were detected in Bizijang due to the addition of powdered Letinus edodes. Linaool and ${\beta}-lonone$ were detected in Jigeumjang due to the addition of powdered red pepper.