• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.31-34
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• 2010

Noble N-substituted-3-fluoropyrroles derivatives were prepared from new precursor via ring formation. The addition reaction of ethyl iododifluoroacetate to vinyl trimethylsilane under the Cu(0) catalyst resulted in the formation of ethyl-2,2-difluoro-4-iodo-4-(trimethylsilyl)butanolate, which reacted with diisobutylaluminium hydride at $-30^{\circ}C$ to yield 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal. Finally, a series of N-substituted-3-fluoropyrrole derivatives were synthesized by the reaction of 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal with $NH_4OH$ or primary amines followed by reaction with KF solution.

• Food Science and Preservation
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• v.13 no.4
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• pp.483-489
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• 2006

Considering the development of fusion ingredients rom red ginseng and Cheonggukjang (soybean-fermented food), their commercial powders were evaluated in their Hunter's colors, volatile compounds, and sensory properties depending on manufacturing companies and mixing ratio of both powdered products. Hunters L, a and b values of red ginseng powders were $75.56\sim85.50,\;1.90\sim6.30,\;and\;23.29\sim35.08$, respectively, while those of Cheonggukjang powders were $64.96\sim71.69,\;4.64\sim8.30,\;and\;30.45\sim36.50$, respectively. Volatile compounds were mainly composed of hexanal, $\beta-pinene$, methyl benzene, 3,5-methyl propyl nonane, 2-propanone, decane, and 2,8-dimethyl undecane in red ginseng samples, and of 2,3-butanedione, decane, 2,2,7,7-tetramethyl octane, and 3-methyl butanal in Cheonggukjang samples. Total volatiles of the mixed samples decreased as ginseng decreased and Cheonggukjang increased. The mixed sample of both red ginseng and cheonggukjang in same amounts was the highest in its sensory acceptability, which was composed in the order of 2-propanone, 2-butanone, pentane, hexanal and 3-methyl butanal. The above results indicate that red ginseng and Cheonggukjang showed a potential as fusion ingredient for preparing new functional produce through further processing.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.78-83
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• 2005

Purge & Trap method was applied to perform more simple and rapid detection for analysis of volatile flavor compounds in milk. Maximal sampling of 30 mL milk for glass flask sparger was treated by He gas purging for 2 hours. Reported major volatile compounds were detected by GC-MS after 2 hours absorption and desorbed from Purge & Trap equipped with Tenax trap. Volatile flavor compounds were analyzed by Purge & Trap and GC-MS to investigate the changes of flavor components in milk between raw and deodorized milk. Fourteen volatile compounds including acetaldehyde, ethanol, 2-propanone, dimethyl sulfide, isobutanal, 3-methyl 2-butanone, 2-butanone, 3-methyl butanal, pentanal, 3-hydroxy-2-butanone, methyl disulfide, hexanal, and 2 others were detected. Six compounds such as ethanol, dimethyl sulfide, pentanal, 3-hydroxy-2-butanone, and methyl disulfide were completely eliminated after deodorization treatment. Four compounds such as 3-methyl 2-butanone, 2-butanone, 3-methyl butanal, and an unknown compound 81 (M/sup +/) were also decreased after raw milk was deodorized. The other four compounds such as acetaldehyde, 2-propanone, hexanal, and an unknown compound (M/sup +/) were not decreased.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.392-398
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• 2005

Fresh, and sun- and oven-dried red peppers were analyzed for volatile components. Also, their odor-active compounds were determined using gas chromatography-olfactometry (GC-O). More diverse volatile components, such as aldehydes, ketones, acids, and esters, were found in dried samples than in fresh ones. They included hexanal, ethyl acetate, ${\alpha}$-ionone, and ${\beta}$-ionone. Some Strecker aldehydes, 2-methyl butanal and 3-methyl butanal, were found only in dried red peppers. More hydrocarbons of high volatility and terpene-type components, such as ${\gamma}$-terpinene and aromadendrene, were detected only in fresh red peppers. A considerable amount of naphthalene was formed during sun-drying, whereas 2-furancarboxaldehyde, 1-methyl-1H-pyrrole and benzeneethanol were detected only in oven-dried red peppers. Characteristic odor of fresh ones could be attributed to 3-penten-2-o1, 2-methyl-2-butenal, 2-methoxy phenol, 2-hydroxy-methyl-benzoate, and 2-phenoxy ethanol, whereas some odorants, including 2-pentyl furan, naphthalene, hexyl hexanoate, and ${\alpha}$-ionone, could be responsible for distinctive odor property of sun-dried red peppers. 2-Furancarboxaldehyde, benzeneethanol, 4-vinyl-2-methoxy phenol, and unknown played important roles in odor property of oven-dried red peppers.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.614-618
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• 2007

The effect of irradiation on the quality characteristics of lyophilized kimchi powder was investigated in order to develop a commercial kimchi seasoning. Fresh and fermented kimchi powders were irradiated at 0, 1.5, 5, 10 and 30 kGy using a Linear Accelerator. By increasing the irradiation dose level, $a^*$ (redness) and $b^*$ (yellowness) values of the kimchi powders were decreased, while $L^*$ (lightness) value remained relatively unchanged as compared to the control. As the main volatile compounds, butanal, 2-butanone and acetic acid were produced in both of the kimchi powders at 30 kGy and dipropyl disulfide was detected only in the fermented kimchi. The viable counts of aerobic bacteria, yeasts, molds, and lactic acid bacteria in the kimchi powder were significantly reduced by all irradiation doses. However, aerobic and lactic acid bacteria were still observed in both of the kimchi powders at 30 kGy. No significant off-odors or off-tastes were produced in either of the kimchi powders by irradiation, while pungency decreased after irradiation. These results suggest that irradiated kimchi powder could be used as a kimchi seasoning.

• Journal of the Korean Chemical Society
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• v.46 no.6
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• pp.541-544
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• 2002

Prepartion of the title compounds at 0-5$^{\circ}C$ is reported along with their AM1 SCF MO calculations. The advantage of this procedure is the hight purity of the produ cts.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.65-68
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• 1971

The possibility of the two-phase oxidation of an aldehyde to carboxylic acid was studied. Thus the ether solutions of representative aldehydes (2.0M) were treated with 1.5 mole equivalent of chromic acid solution (1.0M) for 30 minutes at room temperature. Of the ten aldehydes tested,m butanal, benzaldehyde, tolualdehyde, o-, m-, p-nitrobenzaldehyde and cinnamaldehyde could be oxidized conveniently to the corresponding carboxylic acid giving an 80-90% yield. But furfural gave only a 30% yield of furoic acid and the oxidation of salicylaldehyde was unsuccessful.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.52-56
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• 1993

Flavor compounds formed in the ramyon fried in palm oil at $148-150^{\circ}C$ for 1 minute during storage at $65^{\circ}C$ were isolated and identified by gas chromatography-mass spectrometry. Their changes in the amount when the ramyon was stored at 20, 40 and $65^{\circ}C$ were also studied by using static headspace gas chromatography. Pentane, hexane, butanal, heptane, 1-pentanol, hexanal, and octane were formed during $65^{\circ}C$ storage of the ramyon and they were thought to be from linoleic and oleic acid present in ramyon. Formation of the flavor compounds was shown to increase with the storage temperature and/or storage time. Hexanal showed the highest correlation with the sensory score(r=0.87).

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.292-298
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• 1991

Volatile aroma concentrates of Pleurotus sajor-caju which stored at $20^{\circ}C$ incubator and cold room were obtained by simultaneous distillation-extraction method. The volatile components were identified by combined capillary gas chromatography-mass spectrometry and comparison of retention data on GC of those authentic compounds. Storage at room temperature resulted in significant decreased in their total aroma contents, whereas little changes at cold storage foured, even though appreciable changes were observed in GC pattern between the control and stored samples. Of 38 components identified, ${\delta}-decalactone$ increased while rest of the volatiles decreased rapidly during storage at room temperature, but at cold storage 2-methyl butanal, 1-octen-3-ol, cis,cis-1,5-octadien-3-ol and pentadecanoic acid decreased while 3-octanone, 1-octen-3-one, 3-octanol and 5-undecanol increased with the storage time. The weight losses and organoleptic properties changed extremely by the storage under room temperature, on the other hand, slight changes were found in cold storage.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.34-37
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• 2003

화산석 담체를 충전한 biofilter에서의 ethyl acetate와 2-butanal의 혼합가스의 제거특성에 관한 실험결과는 다음과 같았다. 유입농도 변화 실험에서 EBCT를 30 sec로 유지한 채 혼합가스의 유입농도를 50 ~ 550 ppm 까지 단계적으로 농도를 증가시키면서 살펴본 결과 ethyl acetate는 300 ppm까지 99.9%의 제거효율을 보였으며, 2-butanol은 250 ppm까지 99.9%의 제거효율을 보였다. 유입유량 변화 실험에서 혼합가스의 유입농도를 150 ppm로 일정하게 하고서 EBCT를 60, 30, 15, 10 및 7.5 sec로 단계적으로 감소시킨 결과, EBCT가 15 sec로 유지하여 운전하더라고 99.9%의 높은 제거효율을 보였다. 또한 ethyl acetate 및 2-butanol의 최대제거용량은 각각 180 b/㎥/hr로 산정되었다. 이러한 결과들은 화산석이 biofilter의 충전 담체로 우수함을 보여주었다.