• 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.

• Food Science and Industry
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• v.50 no.4
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• pp.24-49
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• 2017

Volatile flavor compounds of cheonggukjang and doenjang, which are the most representative Korean soybean fermented foods, were compiled throughout literature review. Total of 225 and 404 volatile flavor compounds were found in cheonggukjang and doenjang, respectively. The most characteristic volatile flavor compounds in cheonggukjang are thought to be pyrazine compounds. In addition, acids, such as 2-methyl propanoic acid, butanoic acid, 2-methyl butanoic acid, and 3-methyl butanoic acid, contribute to aroma characteristics of cheonggukjang. On the other hand, ester compounds are the most predominant volatile flavor compounds in doenjang. Ninety six ester compounds were detected in doenjang while 22 ester compounds were identified in cheonggukjang. Pyrazine compounds and acids also play an important role in the flavor of doenjang. Compilation of volatile flavor compounds from cheonggukjang and doenjang will provide basic information to food industry to understand and improve aroma characteristics of cheonggukjang and doenjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.52-58
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• 1991

Physico-chemical properties including the composition of organic acids and fatty acids in native bee-honey and foreign bee-honey harvested in Kangwon area were studied with the emphasis on the honey which was collected form wild flowers nd mixed flowers sources for honey nectars. the major organic acids were considered as acetic acid formic acid and valeric acid in volatile acids and gluconic acid maleic acid malic acid quinic acid and citric acid in non-volatile fraction in both of native bee-honey and foreigr bee-honey. Some naturally occuring fatty acids({{{{ { C}_14{ } }}}}-{{{{ {C }_{20 } }}}}) were observed with the principal fatty acids of myristic aicd linolenic acid and palmitic acid and palmitic acid in the various honey, The characteristics of moisture content pH viscosity free acidity lactone and total acidity were also analyzed and discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.183-188
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• 1978

In this study, gas chromatographic analysis was carried out on volatile constituents of cooked squid for the object of obtaining information on the characteristic flavor of the cooked squid meat. The results obtained are as follows: 1) Methanol was the most effective solvent for the extraction of volatile constituents of squid meat. 2) Twenty five and thirty two peaks were detected from the condensate collected in cold traps which were immersed in ice water and dry ice-acetone, respectively. In these compounds, five kinds of volatile organic acids such as acetic acid, butyric acid, iso-valeric acid, valeric acid, and caproic acid were identified. 3) Eleven peaks were detected from the head space vapor collected in cold trap which is immersed in liquid nitrogen. Volatile amines identified in these components are as follows; methylamine, trimethylamine, dimethylamine, ethylamine, and iso-propylamine.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1440-1446
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• 1999

Fourty-two commercial vinegars were analyzed for their non-volatile organic acids, free sugars. amino acids, and volatile compounds. A study was made to characterize commercial vinegars chemically into three kinds of vinegars such as spirit, cider, and brown rice vinegars. Sixteen chemical components were significantly effective for the chemical characterization of commercial vinegars by stepwise discriminant analysis. Those were malic, succinic and lactic acids from the non-volatile organic acids; fructose and glucose from the free sugars; lysine, serine, leucine, valine and alanine from the amino acids; 1-hexanol, acetaldehyde, 3-methyl-1-butanol, 2-methylpropanoic acid, isopropyl butanoate and ethanol from the volatile compounds. Six components including malic acid, lysine, succinic acid, glucose, lactic acid and 1-hexanol were the most significant contributors to the differentiation of commercial vinegars into spirit, cider, and brown rice vinegars. In particular, cider vinegars could be characterized to be abundant in amounts of malic acid and 1-hexanol, whereas brown rice vinegars in amounts of lysine and lactic acid compared to spirit vinegars.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.745-751
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• 1997

Volatile flavor components of kochujang made from a glutinuous rice by traditional method were analyzed by using purge and trap method during fermentation, and identified with GC-MSD. Fifty-one volatile components including 19 alcohols, 13 esters, 7 acids, 3 aldehydes, 1 alkanes, 2 ketones, 2 amines, 1 benzene, 1 alkene, 1 phenol and others were found in kochujang made by traditional method. The number of volatile components detected immediately after making kochujang were 22 and increased to 41 components after 30 day of fermentation. The most number 51 of volatile components were found after 120 day of fermentation. Twenty-two volatile components were commonly found through the fermentation period such as acetic acid ethyl ester, ethanol, butanoic acid ethyl ester, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, butanoic acid and ethenone. Peak area(%) of 1-butanol was the highest one among the volatile components at immediately after mashing while ethanol showed the highest peak area after 30 day of fermentation. Although the various types of peak areas of volatile components were shown in kochujang during the fermentation days, acetic acid-ethyl ester, ethanol, butanoic acid-ethyl ester, 1-butanol, 3-methyl-1-butanol and 2-methyl-1-propanol were mainly detected during fermentation. Those might be the major volatile components in kochujang made by traditional method.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.1-10
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• 2003

All optional ingredient, Jasoja(Perillae semen) was adopted to improve Dongchimi in qualify during fermentation. Free sugar, free amino acid, non-volatile organic acid and volatile compounds were determined during fermentation at 10$^{\circ}C$ for 45 days. Free sugar content was slightly higher in 0.5%-Jasoja-treated samples than that of control. The contents of free amino acids in control Dongchimi (without jasoja) increased slowly during fermentation while those in 0.5 %-treated samples began to decrease after reaching their maximum value on the day 11 when Dongchimi became most acceptable. There were 6 non-volatile organic acids, such as lactic, fumaric, succinic, malic, tartaric, and citric acid. Among these, only lactic and succinic acid increased consistently with fermentation while others decreased. Volatile components in Dongchimi were mostly identified as sulfur-containing compounds by gas chromatography. Their numbers and % peak areas in the gas chromatogram decreased slightly with the increase in organic acids and alcohols during fermentation period. On the other hand, Dongchimi prepared with Jasoja maintained its contents of total acids as well as the level of sulfur-containing compounds.

• Food Science and Preservation
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• v.4 no.1
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• pp.61-68
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• 1997

To enhance the utilization of garlic shoots as food material, the nutritional and volatile flavor com pounds were investigated for garlic shoots, both cold and warm region type garlic shoots. Proximate composition of cold and warm region type was as follows, respectively; crude protein 2%, crude lipid 0.4%, crude ash 1.1% and 1.5%, crude fiber 1.3% and 1.5%. The major fatty acids of 2 varieties of garlic shoots were linoleic, palmitic and linolenic acid, and their desaturation ratio of them was comparatively high, showing 73.7 and 66.8%, respectively. Free sugars were composed of glucose, sucrose, fructose, arabinose and sorbitol. In the total amino acid analysis, the major amino acids were glutamic acid and aspartic acid. The volatile flavor compounds of fresh garlic shoots extracted by hexane and Likens-Nikerson steam distillation apparatus were identified to be methyl-2-propenyl disulfide, diallyl disufide, propenyl propyl disulfide, di-2-propyl-trisulfide, 2-vinyl-1,3-dithiane, and 2-vinyl-4H-1,3-dithiin. Hexane was more effective than steam distillation for extraction of volatile components of garlic shoots.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.26-32
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• 2000

Preparation and characteristics of a matrix retaining electrolyte using SiC whisker, PES binder, and NMP(n-methyl-2-pyrrolidone) as a non-volatile solvent for a phosphoric acid fuel cell were investigated. The conditions of binder and plasticizer, and the effects of substituting a volatile solvent by a non-volatile solvent were also studied. The minimum amount of the binder was about 17 wt% for the proper bubble pressure and surrounding SiC whiskers. And the maximum amount of the plasticizer was about 10wt% to be fitted into the polymer chain of the binder. The matrix prepared by using a non-volatile solvent needed longer time to dry, and its pore size was smaller compared with that of the matrix prepared by using volatile solvent. The small pore size resulted in decrease of the overall pore volume. The ionic conductivity in the condition of the same thickness was decreased due to decrease of phosphoric acid absorbancy. As the internal resistance of the electrolyte increased, the fuel cell performance slightly decreased.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.700-705
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• 2009

In this study, the volatile compounds in 9 commercial fermented soybean pastes were extracted and analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), respectively. A total of 63 volatile components, including 21 esters, 7 alcohols, 7 acids, 8 pyrazines, 5 volatile phenols, 3 ketones, 6 aldehydes, and 6 miscellaneous compounds, were identified. Esters, acids, and pyrazines were the largest groups among the quantified volatiles. About 50% of the total quantified volatile material was contributed by 5 compounds in 9 soybean paste samples; ethyl hexadecanoate, acetic acid, butanoic acid, 2/3-methyl butanoic acid, and tetramethyl-pyrazine. Three samples (CJW, SIN, and HAE) made by Aspergillus oryzae inoculation showed similar volatile patterns as shown in principal component analyses to GC-MS data sets, which showed higher levels in ethyl esters and 2-methoxy-4-vinylphenol. Traditional fermented soybean pastes showed overall higher levels in pyrazines and acids contents.