• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.59-65
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• 2009

The antimicrobial activity-possessing materials were screened in the cell free supernatant (CFS) of fourteen lactic acid-fermenting strains isolated from pig's intestine. Each cell free supernatant of cultured strains was treated with various proteinases, heat, and/or alkali (NaOH). The antimicrobial activities were remained even after the enzyme and heat treatment but disappeared after neutralization with 1M NaOH, implying that the materials would be organic acids rather than proteins. Further purification of CFS through solid phase extraction using Sep-pak $C_{18}$ Cartridges and high performance anion exchange chromatography using Bio-LC system revealed that four organic acids, such as oxalic acid, citric acid, lactic acid, and acetic acid, were the main materials for the activity. Lactic acid was the highest amount in all organic acids, ranging from 54% to 77%. This strongly implies that the lactic acid would be the primary material for the antimicrobial activity in all tested strains.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.278-282
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• 1979

Sugars and organic acids in Korean hot pepper fruit (C, annuum L.) according to its portions, pericarp, seeds and placenta, were determined by gas liquid chromatography (GLC). ${\alpha}-\;and\;{\beta}-fructoses,\;{\alpha}-\;and\;{\beta}-glucoses$, galactose, sucrose and maltose were identified. Major sugar in pericarp was fructose, while those in seeds and placenta were surose and fructose. Amount of free sugars in seeds was higher than that in pericarp or placenta. Succinic, fumaric, malic, tartaric, citric and quinic acids were found. Citric acid was a major organic acid found in pericarp and placenta. The amount of each identified organic acid, however, was similar in seeds. Quantity of total organic acids identified in pericarp or placenta was higher than that in seeds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.208-213
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• 1995

Andong Sikhe in Korea was prepared and fermented at 5$^{\circ}C$ and the taste and flavor compounds were evaluated. Major flavor components were identified by gas chromatography-mass spectrometer as camphene, sabinene, 1-(1, 5-dimethyl-4-hexyl)-4-methyl-benzene, alpha-zingibirene, farnesene, 2, 6-bis(1, 1-dimethylethyl)-4-metethyl-phenol, beta-sesquiphellandrene, calalene, tetradecanoic acid, and 9, 12-octadecanoic acid. The concentration of nonvolatile organic acid such as lactic acid, oxalic acid and citric acid were 18.10mg/100g, 1.04mg/100g and 1.37mg/100g, respectively, and those of other nonvolatile organic acid were a little. The pH and acidity of Andong Sikhe were 4.06 and 0.32 during fermentation and storage.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.31-36
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• 2001

Optimal operation in chromatography is needed to save operation time and the solvent used in multiple chromatographic runs. To this end, many simulation studies of chromatography process have been performed. The relationship between the distribution coefficient and the ionic strength is important in gradient elution ion chromatography. Experimental runs and computer simulations were carried out under linear gradient elution condition in order to compare the experiments and the simulation. Experiments were performed with formic acid under isocratic conditions to determine the simulation equation parameters. Computer simulation was based on three equations which related distribution with ionic strength as follows; K=${\alpha}$I(sup)-${\beta}$, K=A+BI+Cl$^2$and K=y(sub)0+A$_1$$.$e(sup)(-I/m$_1$). The effects of gradient slope on the chromatograms are discussed, and good agreement between the experimental and the simulated results is shown.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.490-493
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• 2003

Enzymatic synthesis of sugar fatty acid esters was investigated in organic solvent using Candida rugosa lipase. To overcome sugars insolubility in organic solvent, sugar absorption procedure was done on a silica gel. The product yield was determined by using ion Chromatography, with various factors such as reaction time, enzyme fatty acid molar ratio, number of carbon in fatty acid.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.120-125
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• 1994

By using a synthetic medium simulated on the amino acid composition of soybeam, the effect of salt concentrations on the production of volatile organic acid by the strains of Zygosaccharomyces rouxii So-3101, a soy sauce yeast, was studied at the concentrations of 12.5, 18.0, 22.0 and 28.5% NaCl. The growth, consumption of glucose, and production of alcohol, total acid and volatile organic acid, showed the highest values at a concentration of 12.5% NaCl, and those values were decreased with an increase in the salt concentration. The ratio of volatile organic acid to total organic acid was remained at approximately the same level within the range of salt concentrations between 12.5~22.0%, whereas the ratio was decreased at a salt concentration of 28.5%. After incubation for 16 days, 8 volatile organic acids, i.e. acetic, propionic, n-butyric, isobutyric, isovaleric, isocaproic, n-caproic, and heptanoic acids, were detected by gas chromatography. Among the volatile organic acids, acetic acid was produced in the appreciable amiunt and its ratio to the other volatile acids was increased with an increase in the salt concentration.A small amount of isocaproic, propionic, isobutyric and isovaleric acids were produced, and n-caproic, n-butyric and heptanoic acids were detected only at the lower salt concentration.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1204-1208
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• 1996

The organic impurities are formed in the p-xylene oxidation process to terephthalic acid(TPA) and they are present in the filtrate(mother liquor) solution or the TPA particles. The organic impurities present in the p-xylene oxidation are formed through side reactions or incomplete reaction. In this study, the main organic impurities, such as benzoic acid, p-toluic acid, p-tolualdehyde, 4-carboxybenzaldehyde, phthalic acid, isophthalic acid, trimellitic acid, and 4-hydroxymethyl benzoic acid were identified simultaneously by gas chromatograghy. The above impurities were reacted with bis(trimethylsilyl)trifluoroacetamide in the mixture of internal standard solution and pyridine solution by trimethylsilylation, where the internal standard solution was made by 99% bis (trimethylsilyl)trifluoroacetamide and 1% trimethylchlorosilane. The main organic impurities above mentioned can be analyzed quantitatively within 50 min.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.907-912
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• 1999

In this study, removal effect of residue pesticides on vegetable and fruit using organic acid salt in alkali solution were investigated by gas chromatography and measurement of detergency. Generally, for the removal methods of residue pesticides and oily pollution were used chemical detergent or organic solvent. Specially, in our experiment, we only used material of food additives and trisodium citrate were superior to other organic acid salt. It was investigated that removal effect of pesticides was superior to chemical detergent.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.283-288
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• 1995

Rapid gas chromatographic profiling method was applied to saliva from healthy subjects for the analysis of free organic acids. Saliva samples were first saturated with NaHCO$_{3}$ and extracted with diethyl ether. The aqueous phase was solid-phase extracted using Chromosorb P as the adsorbent and diethyl ether as the eluent after the acidification and NaCl saturation, followed by triethylamine treatment. The resulting tiiethylammonium salts of acids were directly converted into stable tert.-butyl-dimethylsflyl derivatives, with subsequent analysis by dual-capiuary column gas chromatography and gas chromatograpy -mass spectrometry. From the ten saliva samples studied, twenty eight free organic acids including various fatty acids, hydroxy acids, dicarboxylic acids, md aromatic acids were tentatively identified. Among the acids identified , the concentration of lactic acid was highest for five saliva samples while $\alpha$-hydroxyisocaproic acid was most abundant for me sample, and succinic acid and glycolic acid for two samples. respectively. When the GC profiles were simplified to the corresponding acid retention index spectra of bar graphical form, they presented characteristic patterns for each individual.

• Applied Biological Chemistry
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• v.24 no.2
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• pp.120-125
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• 1981

Organic acids of Kochuzang (red pepper paste) prepared from glutinous rice, polished barley, wheat flour and sweet potato were analyzed by a gas chromatography. Lactic, pyruvic, succinic, fumaric, malic, pyroglutamic and citric acid were identified. And trace amount of oxalic acid was found in the Kochuzang prepared from sweet potato. The dominant organic acid of all samples was pyroglutamic acid, followed by pyruvic and citric acid. The organic acids were lower in Kochuzang from wheat flour than in other samples. The contents of succinic and fumaric acid were highest in Kochuzang prepared from sweet potato and were lowest in polished barley Kochuzang.