• Journal of the Korean Society of School Health
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• v.25 no.1
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• pp.114-121
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• 2012

Purpose: The purpose of this study was to investigate the concentrations of volatile organic compounds at elementary, middle, and high schools in Ulsan and its surroundings. Methods: To assess the hazardous chemicals of the 66 classrooms in the 22 schools, the 6 volatile organic compounds such as TVOCs (Total Volatile Organic Compounds), benzene, toluene, xylene, ethyl benzene and stylene were measured and analyzed from the beginning of May to the end of December, 2009. Results: The mean concentrations of TVOCs in the elementary schools were higher than those of middle and high schools, and multi-purpose classrooms was higher than that in general ones. The benzene and toluene level in schools in Dong-Gu in the vicinity of assorted industrial complexes was higher than that of schools located in other districts around the Ulsan Metropolitan Area. Conclusion: In case of schools in Ulsan Metropolitan Area, elementary school, schools in Dong-Gu, and multipurpose classrooms over general classrooms should be given a high priority for the management of volatile organic compounds.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.761-769
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• 1995

About 2.1g of pale yellow flavor concentrate was obtained from 10kg of chopped fresh ascidians through a Likens-Nickerson steam distilllation/solvent extraction. These concentrates could be fractionated to neutral $(91.5\%),\;basic\;(1.0\%),\;phenolic\;(3.2\%),\;and\;acidic\;(4.3\%)$ fractions. Total 65 volatile compounds were identified from those concentrates. The neutral fraction was representative flavor fraction which showed a similar flavor of total steam distillates of ascidian. The major compounds $(38.2\%\;of\;neutral\;fraction)$ were identified as carbon atoms 8 to 10 of alcohols. Among these volatile alcohols, 1-octanol, 2,7-decadien-1-o1, 3-octen-l-01, 7-decen-l-ol, and l-decanol were the dominent compounds found in neutral fraction. But the basic, phenolic, and acidic fractions differs from ascidian steam distillates flavor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1042-1049
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• 2000

Irradiation-induced volatile flavor compounds in irradiated (1, 3, 5, 10 kGy) beef were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred fifty volatile compounds were detected in irradiated beef. These compounds were composed mainly of 71 hydrocarbons, 35 aromatic compounds, 15 aldehydes, 7 ketones, 4 acids, 6 esters and 12 miscellaneous compounds. Among these, only 6 volatile compounds including (E) -2-hexenal, nonene, 2-nonenal, cyclodecene, dodecene and cyclododecene were detected as irradiation-induced volatile flavor compounds, comparing with unirradiated beef meat. However, 4 volatile compounds, such as cyclodecene (r=0.88), (E)-2-hexenal (r=0.85), nonene (r=0.74) and 2-nonenal (r=0.70), having a positive correlation coefficient with the increment of irradiation dose, were considered as marker compounds for detecting irradiation dosages in irradiated beef.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.412-419
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• 2004

In odor to select optimum extraction methods of volatile compounds in beef extract powder(BEP) as basic data for the development of a new detection method of irradiated BEP, four extraction methods, such as solid phase microextraction with polar fiber(S-PD) and non-polar fiber(S-CD), purge and trap(P&T) and liquid liquid continuous extraction(LLCE) methods, were tested with gas chromatography/mass spectrometry method. A total of 106 volatile compounds including 22 hydrocarbons, 7 aldehydes, 6 ketones, 13 alcohols, 6 sulfur-containing compounds, 19 nitrogen-containing compounds, 6 aromatic compounds, 17 terpenes, 8 furans and 2 miscellaneous compounds were detected in BEP by four detection methods. The most compounds(62 compounds) were detected by S-PD method, followed by P&T(43), LLCE(38) and S-CD method(30). Among these methods, S-PD and P&T methods showed a complementary interrelationship to detect volatile compounds as S-PD method showed high detectabiltiy to all compound groups except hydrocarbons and ketones, which had high volatility and low molecular weight(less than RI 1200), but P&T method showed the contrary pattern to that of S-PD method. Moreover, the most of volatile compounds detected by S-CD and LLCE methods were also detectable by S-PD or/and P&T methods. Therefore, the simultaneous application of S-PD and P&T methods were selected as the optimum volatile extraction methods of BEP.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.111-115
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• 1999

This study was attempted to develop technique of masking the pungent odor of chonggugjang using two-stage fermentation method with mixed pure cultures. Cooked soybeans were fermented with Lactobacilli or Aspergillus oryzae at $38^{\circ}C$ for 36 hrs, and then re-fermented with Bacillus subtilis for 12 hrs. The volatile compounds of chonggugjang were obtained with a SDE(Simultaneous steam Distillation and solvent Extraction) system and the extracts were identified by GC and GC-MS. The experimental results revealed the presence of 35 volatile compounds in control chonggugjang(only Bacillus subtilis inoculation). Among them, the major volatile compounds were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine. Twenty-nine kinds of volatile compounds were in chonggugjang prepared by two-stage fermentation method with Lactobacilli and Bacillus subtilis(II), and major volatile compounds were identified to be 2,3,5-trimethyl pyrazine and 2,5-dimethyl Pyrazine. In chonggugjang(Asp. oryzae and then Bacillus subtilis inoculation(III)), the contents of hexadecanoic acid and 2-methyl pyrazine were patricularly high and the main components of chonggugjang fermented with rice straw(IV) were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine etc. In conclusion, the flavor compounds such as 2, 5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine were increased by the inoculation of Lactobacilli or Asp. oryzae, where as unpleasant odor components-butyric acid and valeric acid were decreased. Compared with volatile compounds of chonggugjang made from different soybean cultivars, the flavor compounds (2-methyl pyrazine 2,5-dimethyl pyrazine 2,6-dimethyl pyrazine 2,3-dimethyl pyrazine 2-acetyl pyrazine 2,3,5-trimethyl pyrazine 2-ethyl-3,5-dimethyl pyrazine) of chonggugiang prepared with Sinpaldalkong were high.

• Food Science and Preservation
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• v.14 no.3
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• pp.308-314
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• 2007

To investigate effects of fermentation on volatile components, we analyzed volatile organic compounds of raw and fermented Rhus verniciflua S. bark. A 50%(w/v) sugar solution was used for fermentation. Volatile organic compounds of raw and fermented Rhus verniciflua S. were extracted by the simultaneous steam distillation and extraction(SDE) method, with a mixture of n-pentane and diethylether(1:1, v/v) and analyzed by gas chromatograph-mass spectrometer. A total of 51 and 27 volatile organic compounds were detected in raw and fermented samples, respectively, and were mainly alcohols. Compounds such as ethyl acetate, 2-methyl-3-buten-2-ol, 3-methylbutanal, 1-octen-3-o1, 3-methyl-2-butanone, hexanal and pentanal were detected as the primary compounds in the raw sample. The fermented sample showed sour different volatile compounds, such as ethanol, ethyl acetate, ethyl lactate and 3-methylbutanol. Thus, a number of volatile organic compounds were synthesized after fermentation of Rhus verniciflua S. bark.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.529-532
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• 2005

Volatile compounds, isolated from Chopi (Zanthoxylum piperitum A.P. DC.) using steam distillation, were analyzed by gas chromatography/mass spectrometry-olfactometry (GC-MS-O). Forty-six volatile compounds, consisting of 12 hydrocarbons, 8 aldehydes, 5 esters, 12 alcohols, 4 ketones, 4 oxides and 1 acid, were tentatively identified from the essential oil of Chopi. Unidentified compounds constituted 7.2% of the total peak area. Limonene was the most abundant compound, followed by geranyl acetate, citronellal, cryptone and ${\beta}$-myrcene. In addition, aroma-active compounds, in particular citronellal and limonene, which are related to the citrus and Chopi flavors of Chopi essential oil, were detected. The aroma of Chopi essential oil had a score of 4.8 on the preference test (neither like nor dislike) and a score of 5.97 on the intensity test (slightly strong) using the 9-point hedonic scale.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.441-446
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• 2006

Volatile flavor compounds in meat of the blue crab Portunus trituberculatus were compared using vacuum simultaneous steam distillation-solvent extraction (V-SDE) and solid phase microextraction (SPME)/ gas chromatography (GC)/ mass selective detection (MSD) methods. A total of 100 volatile flavor compounds were identified by both methods: 77 by V-SDE and 59 by SPME. These compounds were composed of 17 aldehydes, 12 ketones, 19 alcohols, 5 esters, 4 sulfur-containing compounds, 6 nitrogen-containing compounds, 23 aromatic compounds, 6 hydrocarbons, 2 terpenes, and 6 miscellaneous compounds. Although more compounds were detected using V-SDE than using SPME, the levels of all groups detected, except esters, were higher using SPME than using V-SDE. In addition to trimethylamine, aldehydes, and aromatic compounds, the S- and N-containing compounds with low thresholds are thought to have positive roles for flavors in the meat of the blue crab.