• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.209-214
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• 1983

Analytical methods on Stevia sweeteners are compared for their reproducibilities and recoveries. It is possible to separate stevioside, rebaudioside A, rebaudioside C, and dulcoside A through HPLC analysis. Steviolbioside, in addition to above 4 Stevia sweeteners, is detected through TLC scanner and TLC-FID assays. C.V.s on stevioside and rebaudioside A in HPLC analysis are 1.39 and 4.89%, which shows outstanding reproducibilities of this method. The recoveries of stevioside in HPLC, TLC scanner, and TLC-FID analyses are 97.7 89.4, and 97.3%. The recoveries of rebaudioside A in HPLC, TLC scanner, and TLC-FID assays are 90.8, 90.1, and 75.8%. Total content of Stevia sweeteners in 8 strains tested, ranges from 5 to 17% as dry weight basis.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.105-109
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• 1986

Volatile components of pinenut were identified. Pinenut was extracted by simultaneous distillation and extraction method after Soxhlet extraction. The odor profile of the extract was very similar to that of pinenut. This extract was then fractionated into four fractions by Preparative TLC. These all fractions were analyzed by a combination of glass capillary gas chromatography (FTD, FID capillary GC) and mass spectrometry. One hundred and nine components, including 26 hydrocarbons,17 esters,16 aldehydes,12 ketones,31 alcohols, 11 bases, 2 acids and 3 miscellaneous components were identified.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.221-228
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• 1999

This study was carried out to extract the natural antioxidants from Bovine bile and to investigate their effects on various antioxidant activities. It also characterized the patterns of antioxidants by GC/FID and GC/MS. The antioxidative activities and chemical structure of the antioxidant were elucidated by examining the effects of biological activity and the analysis of GC/MS. The antioxidant materials extracted from bovine bile were isolated and purified by silica gel column chromatography and TLC. It was confirmed that there were effects of antioxidants such as Xanthine Oxidase(XO) and Glutathione-S-Transferase(GSH-T) on antioxidative activities. When they were compared with BHT, bile extracts showed the relative effects of 51.2% on the antioxidant activity, the inhibition effects of 48.3% on XO activity, and the synergism effects of 85.7% on the GSH-T activity. According to the results of investigation at neuron cell of mouse, the rate of cell activity in the treatment of 6mM glutathione was 96%, While it in the treatment of 140mg of bile extract was 78%. Based on the TLC analysis of EtOAc extracts from the Bovine bile, the antioxidant activity appeared at $R_f$ value, 0.72. These results suggested that the antioxidant may be coprostan 3-ol.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.360-363
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• 2003

Bioremediation is often used for in situ remediation of petroleum-contaminated site. We studied the microbial degradation of hydrocarbon in an artificially diesel contaminated soil in laboratory microcosm. In control soil, about 30% of the initial TPH was diminished and the degradation of diesel oil was significantly enhanced by the addition of bioremediation agent (70% of TPH reduction).

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.179-183
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• 1982

This experiment was carried out to clarify the optimal concentrations of growth regulators for callus induction and the condition of callus culture of leaf tissue taken from Stevia rebaudiana Bertoni. The content of stevioside, sweetening component, in leaf-derived callus of stevia was also investigated. It was shown that the optimal concentrations of benzyladenine (BA) and ${\alpha}-naphthalene$acetic acid (NAA) for callus induction were $10^{-6}M$ and $10^{-5}M$, respectively. Reculture of these calli in media (Linsmaier and Skoog) supplemented with BA $10^{-6}M$ and NAA $10^{-5}M$ resulted in profuse calli 15 to 20 days after incubation. When sweetening components produced by callus were extracted and identified by TLC, stevioside appeared to have Rf value 0.50 in TLC which was exactly same as standard stevioside. Stevioside content obtained by TLC-FID analyzer was 260mg per 100g on the basis of dry weight.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1672-1678
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• 2009

We studied the effects of aged total petroleum hydrocarbons (aged TPH) on the survival of allochthonous diesel-degrading Rhodococcus sp. strain YS-7 in both laboratory and field investigations. The aged TPH extracted from a crude-oil-contaminated site were fractionized by thin-layer chromatography/flame ionization detection (TLC/FID). The three fractions identified were saturated aliphatic (SA), aromatic hydrocarbon (AH), and asphaltene-resin (AR). The ratio and composition of the separated fractions in the aged TPH were quite different from the crude-oil fractions. In the aged TPH, the SA and AH fractions were reduced and the AR fraction was dramatically increased compared with crude oil. The SA and AH fractions (2 mg/l each) of the aged TPH inhibited the growth of strain YS-7. Unexpectedly, the AR fraction had no effect on the survival of strain YS-7. However, crude oil (1,000 mg/l) did not inhibit the growth of strain YS-7. When strain YS-7 was inoculated into an aged crude-oil-contaminated field and its presence was monitored by fluorescent in situ hybridization (FISH), we discovered that it had disappeared on 36 days after the inoculation. For the first time, this study has demonstrated that the SA and AH fractions in aged TPH are more toxic to an allochthonous diesel-degrading strain than the AR fraction.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.3
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• pp.222-232
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• 2006

Objectives: The objective of this study was to propose the total isocyanate analytical method which involves derivation of 2,4-toluene diisocyanate(2,4-TDI), 2,6-toluene diisocyanate(2,6-TDI), 4,4'-methylenediphenyl diisocyanate(4,4'-MDI) and 1,6-hexamethylene diisocyanate(1,6-HDI) using 2-chlorobenzyl alcohol(2-CBA) or 2,4-dichlorobenzyl alcohol(2,4-DCBA), and analyzing of hydrolysate of the synthesized urethane with the gas chromatography(GC)/flame ionization detector(FID), GC/pulsed discharge ionization detector-electron capture detector(PD-ECD) and GC/mass selective detector(MSD). Methods: Urethanes were synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI to 2-CBA or 2,4-DCBA. Urethanes was verified by TLC, HPLC/UVD and GC/MSD. For field application, the most suitable condition that 2-CBA coated in glass fiber filter removed completely and urethanes were not removed was searched. 2-CBA generated from hydrolysis of urethanes according to hydrolysis conditions. Diisocyanates were collected on field air and analyzed. Results: Urethanes which were white and solid phase synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI, 1,6-HDI and 2-CBA or 2,4-DCBA. And urethanes were verified by TLC, HPLC/UVD and GC/MSD. The most suitable conditions to remove 2-CBA coated in glass fiber filter were $87^{\circ}C$ and 20 mmHg and urethanes were not removed under same condition. Hydrolysis yields of urethanes were 99 % to 111 %. 2-CBA, the hydrolysate of urethanes was analyzed by GC/FID, GC/PD-ECD and GC/MSD. Conclusions: Simultaneous analysis of 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI deriving with 2-CBA and 2,4-DCBA, along with a total isocyanate analysis, was feasible with GC/FID, GC/PD-ECD and GC/MSD. This result will be a guide of further study on total isocyanate analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.35-36
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• 1982

Lipid composition of human milk samples (ten colostrum and 10 mature) was analyzed by quantitative thin-layer chromatography with flame ionization detector. Six kinds of lipid components existed in human milk. Among them, triglyceride which was most abundant lipid component showed significantly lower levels in colostrum than in mature milk. Other lipid components have no significant differences between colostrum and mature milk.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1157-1157
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• 2001

Yeast, Kurtzurnanomyces sp. I-11, produces biosurfactant, mannosyl erythritol lipid (MEL), from soya oil. The properties of biosurfactant MEL include low-toxicity and high biodegradability. MEL provides new possibilities for a wide range of industrial applications, especially food, cosmetic, pharmaceutical fields and chemicals for biotechnology. In the fermentation process, techniques of measuring and controlling substrates and products are important to obtain high productivity with optimum concentrations of substrate and product in the culture broth. The measurement system for the concentrations of soya oil and MEL in the fermentation process was developed using near-infrared spectroscopy (NIRS). Soya oil and MEL in the culture broth were extracted with ethyl acetate and NIR spectra was carried out between the second derivative NIR spectral data at 1312 and 2040 nm and MEL concentrations obtained using a thin-layer chromatography with a flame-ionization detector (TLC/FID) method. A calibration equation for soya oil was results of the validation of the calibration equation, good agreement was observed between the results of the TLD/FID method and those of the NIRS method for both constituents. NIR method was applied to the measurement of the concentrations of MEL and soya oil in the practical fermentation and good results were obtained. The study indicates that NIRS is a useful method for measurement of the substrate and product in the glycolipid fermentation.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.277-284
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• 2011

The compositions of health functional food products (HFFP; 18 products) containing gamma linolenic acid (GLA; $C_{18:3}$, n-6) and omega-3 fatty acids (EPA and DHA) were investigated. The contents of index components (especially, GLA and omega-3) in HFFPs were monitored by GC-FID analysis. Among the GLA products (sample No. 1~8), the content of GLA in most samples (except sample No.6) ranged from 8.04 to 9.98 g/100 g. These results were suitable for the reference standard (more 7.0 g/100 g) of HFF. In the omega-3 products (sample No. 10 and 15) derived from harp seal oil (HSO), the total contents of EPA and DHA were 14.21-15.98 g/100 g, respectively. These values were suitable for the reference standard (more 12.0 g/100 g) of HFF. Besides, among the omega-3 products (sample No.9, 11~14, 16~18) derived from fish oil, the total content of EPA and DHA ranged from 24.11 to 31.20 g/100 g. These results were suitable for the reference standard (more 18.0 g/100 g) of HFF. In the result of TLC analysis, the HFFPs of 18 were mainly composed of triacylglycerols (TAGs). The content of trans fatty acid in 18 HFFPs was detected in less than 0.30 g/100 g. For the detection of trans fatty acid, $^1H$-NMR (600 MHz) can be used because chemical shift of trans fatty acid was observed at 5.3 ppm in this study.