• Food Science of Animal Resources
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• v.31 no.4
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• pp.596-602
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• 2011

The objective of this study was to analyze the pattern recognition of volatile compounds from different types of milk under LED (Light Emitting Dioxide) irradiation for 6 d. Yellow, red, blue, dark, and fluorescent light were produced using LED equipment. A mass spectrometry-based electronic nose and DFA (discriminant function analysis) were used to determine the change in volatiles from different types of milk under LED irradiation. As the LED exposure time was increased, DF1 of whole milk changed considerably under blue light, while that of skim milk changed significantly under red and yellow light irradiation. Among the types of milk tested, the most light-induced oxidation sample was LTLT milk under blue light. The volatile compounds that were shown to increase due to LED treatment in the electronic nose analysis, which was based on MS, were mainly acetaldehyde, propanal, pentanal, hexanal, heptanal, nonanal, 3-methyl butanal, 2-methyl propanal, 2-butanone, 2-pentanone, 2-hexanone, and 2-heptanaone and 2-nonanone.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.437-441
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• 1985

In order to elucidate the flavor compounds of fermented big eyed herring, Harengula zunasi (BLEEKER), and slimy, Leiognathus nuchalis (TEMMINCK et SCHEGEL), the volatile constituents of products were analysed by GLC. In the volatile compounds of fermented big eyed herring, eight kinds of volatile fatty acids, nine kinds of volatile carbonyls, and five kinds of volatile amines were identified. While in the fermented slimy, seven kinds of volatile fatty acids, six kinds volatile carbonyls, and five kinds of volatile amines were also identified. In the volatile fatty acids and volatile amines, n-butyric acid and trimethylamine were the most dominant component in both fermented products. In the fermented big eyed herring 2-methylpropanal, ethanal, and propanal were abundant holding 36.2%, 28.5%, and 16.2%, while in the fermented slimy ethanal, 2-methylpropanal, and propanal were abundant holding 44.7%, 24.1%, and 14.4% of total volatile carbonyls, respectively. From the experimental results, it was concluded that n-butyric acid, trimethylamine and volatile carbonyls such as 2-methylpropanal, ethanal and propanal played an important role in the flavor of the fermented big eyed herring and slimy.

• 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.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.220-228
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• 2004

Dynamic headspace purge conditions were investigated to obtain minimum loss of high volatile compounds by breakthrough and maximum recovery of low volatile components of roasted perilla seed oil (RPSO). A response surface methodology was applied to evaluate the effect of purge temperature, purge time, and sample weight on $\ell$ n (total peak area), breakthrough ratio, and peak area of perilla ketone the least volatile component of RPSO. Sample weight was the most important factor on the $\ell$ n (total peak area) but it did not affect peak area of perilla ketone. All process variables significantly influenced breakthrough ratio. The optimum condition was determined by superimposing contour plots at purge temperature of 48$^{\circ}C$ for 12 min purge time at sample weight of 0.60 g. 2-Propanone, 2-butanone, acetic acid, 2-methyl propanal were main breakthrough compounds in RPSO flavor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.121-128
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• 1989

Volatile compounds were collected by simultaneous distillation extraction and carbon dioxide method, and analyzed by GC and GC-MS. The neutral fraction obtained from the whole steam volatile concentrate 55 kinds of components, phenolic fraction had 4 kinds of components, basic fraction had 13 kinds of components and 10 kinds of components were in acidic fraction. Alcohols, propanols, butanols, octanols, dodecanols etc. and aldehydes, pentanals, hexanal, 2-methyl-1-propanal, heptenal etc. were highly increased after boiled and roasted. And these compounds were contributed to formation of filefish flavor. The molecular ion peak of phenolic fraction was generally appeared in the range 100 to about 160. From the basic fraction, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-3,5-di-methylpyrazine and 2-methylpyridine were identified. The contents of basic compounds and furans obtained from the neutral fraction were increased at the higher heating temperature. The flavor of acidic fraction was influenced by the low molecular as isovaleric and valeric acid.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1243-1249
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• 2006

Volatile flavor compounds in commercial crab-like flavorants were compared by mean of solid phase microextraction(SPME) and liquid continuous extraction (LLCE)/GC/MSD methods. A total of 86 volatile flavor compounds were detected. Of these, 71 were positively identified consisting mainly of sulfur-containing compounds (13), aldehydes (3), ketones (2), esters (26), alcohols (5), aromatic compounds (3), terpenes (8), acids (2) and miscellaneous compounds (9). SPME method was more effective than LLCE method in detection of volatile components in commercial crab-like flavorants. Eight S-, N-containing compounds such as dimethyl sulfide, dimethyl disulfide, dipropyl disulfide, 3-(methylthio)propyl acetate, 3-(methylthio) propanal, 3-(methylthio) propanol, 2-methyl-3-(methylthio) pyrazine and 2-methyl-5-(methylthio) pyrazine, 8 esters such as styrallyl acetate, ethyl acetate, isoamyl acetate, benzyl acetate, ethyl pentanoate, butyl pentanoate, isoamyl pentanoate and furfuryl acetate were considered as major components in crab-like flavorants.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.494-501
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• 1993

The volatile flavor components of traditional and commercial kochujang were collected by simultaneous steam distillation-extraction (SDE) method. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC/MS). Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, Sachun kochujang prepared with wheat and commercial kochujang. One hundred and twelve volatile flavor components which included 30 esters, 15 alcohols, 14 aldehydes, 13 acids, 9 ketones, 7 alkenes, 6 phenols, 3 alkanes, 3 pyrazines, 2 benzenes and 2 furans were identified. The major volatile compounds in traditional and commercial kochujang were 2-methyl propanal and ethanol, which represented $21{\sim}36%\;and\;2{\sim}44%$ of total GC peak area, respectively.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.604-608
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• 2008

A series of N-alkenyl pyrrolidine-2-thiones were synthesized by the reaction between pyrrolidine-2-thione and various aldehydes such as n-propanal, isopropanal, n-butanal, n-hexanal, n-octanal and phenylacetaldehyde in 32-86% yields using microwave irradiation technique. Only one structural E isomers were predominantly formed within 15 minutes in chlorobenezene?/p-toluenesulfonic acid monohydrate.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.286-290
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• 2006

Rapid and facile syntheses of N-alkenyl lactam series via condensation between lactams and a variety of aldehydes such as n-propanal, isobutanal, n-butanal, n-hexanal, n-octanal and phenylacetaldehyde were studied under microwave or conventional heating. Various solid catalysts and solvents were examined to maximize the yields of condensation reactions.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.909-918
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• 1996

Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).