• Membrane Journal
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• v.14 no.1
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• pp.37-43
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• 2004

As the experimental results of membrane application for the production and recovery of volatile fatty acids, suspended solids concentration, the number of acid producing bacteria and organic acid concentration increased with membrane coupling in the fermenter. The application of membrane for the efficiency increase of solid-liquid separation and fermentation made the number of acid producing bacteria increase in the fermenter, thus acid forming rate showed higher value than that of membrane-free fermenter. Membrane-coupled fermenter was believed to be an effective technology for the improvement of recovery efficiency of volatile fatty acids from organic sludge.

• Clean Technology
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• v.22 no.3
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• pp.203-207
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• 2016

Here, we report a novel fabrication technique for patchable organic lasing sheet based on non-volatile liquid organic semiconductors and freestanding polymeric film with high flexibility and patchability. For this work, we have fabricated the second-order DFB grating structure, which leads to surface emission, embedded in the freestanding polymeric film. Using an ultra-violet (UV) curable polyurethaneacrylate (PUA) mixture, the periodic DFB grating structure can be easily prepared on the freestanding polymeric film via a simple UV curing process. Due to unsaturated acrylate remained in the PUA mixture after UV curing, the freestanding PUA film provides adhesive properties, which enable mounting of the patchable organic lasing sheet onto non-flat surfaces with conformal contact. To achieve laser actions in the freestanding resonator structure, a composite material of liquid 9-(2-ethylhexyl)carbazole (EHCz) and organic laser dyes was used as the laser medium. Since the degraded active materials can be easily refreshed by a simple injection of the liquid composite, such a non-volatile liquid organic semiconducting medium has degradation-free and recyclable characteristics in addition to other strong advantages including tunable optoelectronic responses, solvent-free processing, and ultimate mechanical flexibility and uniformity. Lasing properties of the patchable organic lasing sheet were also investigated after mounting onto non-flat surfaces, showing a mechanical tunability of laser emission under variable surface curvature. It is anticipated that these results will be applied to the development of various patchable optoelectronic applications for light-emitting displays, sensors and data communications.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.296-302
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• 2013

This study was carried out to investigate the effect of organic content level on ultimate methane potential and anaerobic biodegradability of substrate by biochemical methane potential assay. Three organic matters (whole sludge and liquid and solid fraction of sludge) of the same origin, which had different organic contents, were fermented at the batch anaerobic reactor for 70 days. Ultimate methane potential and anaerobic biodegradability were determined by the terms of volatile solid (VS) and chemical oxygen demand (COD). Volatile solid contents of whole sludge and solid and liquid fraction of sludge were 2.4, 18.8, and 0.2% and COD were 5.3, 30.4, and 0.5%, respectively. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{VS}$) determined by VS content were $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for whole sludge, $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for the liquid fraction of sludge, and $0.6Nm^3kg^{-1}-VS_{added}$, 77.0% for the solid fraction of sludge. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{COD}$) determined by COD were $0.2Nm^3kg^{-1}-COD_{added}$, 73.4% for whole sludge, $0.2Nm^3kg^{-1}-VS_{added}$, 74.0% for the liquid fraction of sludge, and $0.33Nm^3kg^{-1}-COD_{added}$, 99.1% for the solid fraction of sludge. In conclusion, ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results because COD might be underestimated by the interference of $NH_4{^+}$ in the case of highly concentrated organic material.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.800-808
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• 2003

Three strains of yeasts, Pichia farinosa SKM-1, Pichia anomala SKM-T, and Galactomyces geotrichum SJM-59, produced volatile flavor compounds during fermentation. To investigate these volatile flavor compounds, the liquid culture broth of the three yeast strains were extracted with methylene chloride, and then GC and GC-MS analyses were conducted. Flavor analyses revealed that 5, 12, and 15 kinds of volatile compounds were isolated, and 4, 8, and 11 volatile flavor compounds were identified, respectively. Phenylethyl alcohol was identified with the common volatile flavor compound of Pichia farinosa SKM-1, Pichia anomala SKM-T, and Galactomyces geotrichum SJM-59. 1H-indole-3-ethanol, a precursor of plant growth hormone, was identified from Pichia anomala SKM-T.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.122-127
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• 2016

The objective of this study was to identify the volatile compounds and aroma-active compounds from acai berry (Euterpe oleracea). Volatiles were isolated by high vacuum distillation using solvent-assisted flavor evaporation (SAFE) and liquid-liquid continuous extraction (LLCE). To identify the characteristic aroma-active compounds of acai berry, gas chromatography-mass spectrometry-olfactometry was used. Aroma-active compounds were evaluated by aroma extract dilution analysis (AEDA). A total of 51 and 54 volatile compounds from acai berry were identified from SAFE and LLCE extracts, respectively. Alcohols were confirmed to be important volatile compounds in acai berry, as the major volatile compounds were 2-phenylethanol, (Z)-3-hexenol, and benzyl alcohol. ${\beta}-Damascenone$ (berry, rose), trans-linalool oxide (woody), (Z)-3-hexenol (grass), and 2-phenylethanol (rose, honey) were considered the aroma-active compounds in acai berry. The most intense aroma-active compound of acai berry was ${\beta}-damascenone$.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.651-661
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• 2024

Chicken broth has a taste of umami, and the stewing time has an important effect on the quality of chicken broth, but there are fewer studies on the control of the stewing time. Based on this, the study was conducted to analyze the effects of different stewing times on the sensory, small molecular metabolites, free fatty acids, and volatile flavor compounds contents in chicken broths by liquid chromatography-quadrupole/time-of-flight mass spectrometry, gas chromatography-mass spectrometry, headspace solid-phase microextraction, and gas chromatography-mass spectrometry. Eighty-nine small molecular metabolites, 15 free fatty acids, and 86 volatile flavor compounds were detected. Palmitic and stearic acids were the more abundant fatty acids, and aldehydes were the main volatile flavor compounds. The study found that chicken broth had the best sensory evaluation, the highest content of taste components, and the richest content of volatile flavor components when the stewing time was 2.5 h. This study investigated the effect of stewing time on the quality of chicken broth to provide scientific and theoretical guidance for developing and utilizing local chicken.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1032-1037
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• 2008

Lowly volatile heterocyclic sulfur compounds generated in autoclaved garlic extract were isolated and identified, and their antimicrobial activity was determined. Two kinds of unusual volatile sulfur compounds were separated from heated garlic by preparative recycling high performance liquid chromatography (HPLC), and identified by gas chromatography (GC)-mass spectrometry (MS) and $^1H$-nuclear magnetic resonance (NMR). They had heterocyclic structures with 4 to 5 sulfur atoms in the molecules. 4-Methyl-1,2,3-trithiolane (MTTT) is highly volatile and was not able to be concentrated, and was identified by GCMS only. MTTT and 6-methyl-1,2,3,4,5-pentathiepane (MPTP) are lowly volatile and were obtained in pure states to be positively identified for the first time. All 3 heterocyclic sulfur compounds began to appear by the time when the early-formed diallyl sulfides started to disappear. The minimum inhibitory concentration range of MTTT and MPTP was determined to be between 1 and 6 ppm against all yeasts tested. MTTT and MPTP were lowly volatile and sparingly soluble in water.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.115-123
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• 1998

The semi-volatile fraction of cigarette mainstream smoke contains the most important aroma and taste that enhance smoke flavor. The components in mainstream smoke were analysed for commercially available cigarettes. To compare the semi-volatile components delivered from mainstream smoke of domestic cigarette with imported cigarette, we analyzed three types of filter cigarettes such as cellulose acetate mono filter, carbon dual filter and slim filter cigarette. Mainstream smoke was collected with a combination of Cambridge filter pad and liquid trap containing a small amount of acetone cooled by dry ice-methanol. We have identified 43 components from mainstream smoke by GC and GC/MS and found that benzene, toluene, 4-hydroxy-4-methyl-2-pentanone, 5-methyl-2-furaldehyde, acetic acids nicotine and triacetin were the main peaks in mainstream smoke. Also we have compared the relative amounts of semi-volatile compounds delivered from the domestic and imported cigarettes with three different filters. From the results of this study, the relative amounts of limonene, acetic acid, 5-methyl-Lfuraldehyde delivered from the imported cigarettes were generally higher than those of the domestic one's.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.179-185
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• 1996

Extraction yields of thiosulfinates from garlic were studied by using gas-in-liquis-dispersion(GLD) system to maxmize the thiosulfinate extraction. Extracted thiosulfinates were spectrophotometically quantified using synthesized dially1 thiosulfinate. The conditions for maximum extraction were optimized by response surface methodology. The volatile components extracted by various methods, such as hexane extraction, simultaneous steam distillation and GLD system, were compared by using gas chromatography. The results indicated that the thiosulfinate yield was increased by incresaing temperature and nitrogen gas flow rate, while the effects of bubble sizes on thiosulfinate extraction were not significant at the ranges tested. Application of GLD system resulted in extraction of more volatile components than other extraction methods, Therfore, it was suggested that GLD system was one of the efficient extraction methods among the ever introduced ones, for thiosulfinate extraciton.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.167-175
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• 2016

The volatile component analysis of 82 commercialized liquors(44 samples of single malt whisky, 20 samples of blended whisky and 18 samples of brandy) was carried out by gas chromatography after liquid-liquid extraction with dichloromethane. Pattern recognition techniques such as principle component analysis(PCA), cluster analysis(CA), linear discriminant analysis(LDA) and partial least square discriminant analysis(PLSDA) were applied for the discrimination of different liquor categories. Classification rules were validated by considering sensitivity and specificity of each class. Both techniques, LDA and PLSDA, gave 100% sensitivity and specificity for all of the categories. These results suggested that the common characteristics and identities as typification of whiskies and brandys was founded by using multivariate data analysis method.