• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.915-931
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• 2009

The non-rigid molecule group theory in which the dynamical symmetry operations are defined as physical operations is applied to deduce the character table of the full non-rigid molecule group (f-NRG) of 2,3,5,6-Tetramethylpyrazine The f-NRG of this molecule is seen to be isomorphic to the group $\mathbb{Z}_3{\wr}(\mathbb{Z}_2{\times}\mathbb{Z}_2)$, where $\mathbb{Z}_n$ is the cyclic group of order n, of order 324 which has 45 conjugacy classes. We determine the some properties and relations between characters of the group. Also, we examine the symmetry group of this molecule and show that its symmetry group is $\mathbb{Z}_2{\times}\mathbb{Z}_2$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.481-489
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• 1994

Volatile flavor compounds in low salt-fermented anchovy pastes by adding koji(Koji), compared with Control, were analyzed by simultaneous steam distillation -solvent extraction /gas chromatography/mass spectrometry. Volatile compounds (106) were detected inboth samples during fermentation. Among these, 79 compounds were positively identified and were composed mainly of aldehydes, esters, alcohols, ketones, nitrogen-containing compounds, aromatic hydrocarbons, and furans. Aldehydes and esters were found higher amounts that other compounds in both samples. Alkylpyrazine, such as 2, 6-dimethylpyrzine, 2-ethyl-6-methylpyrazine, trimethylpyrazie, 2-ethyl-3, 5-dimethylpyrazine and tetramethylpyrazine, and also 2-phenylethanol were identified only in Koji.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.196-201
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• 2000

This study was conducted to investigate various flavor components of barley meju during fermentation. The change of PH was $5.2{\sim}5.6$. L-value and b-value gradually decreased. a-value gradually increased until fifth day and then decreased. Among 75 flavor compounds identified in barley meju, 10 aldehydes and 10 ketones were most in number followed by 9 acids, 9 phenols, 7 hydrocarbons, 7 alcohols and 6 esters. The contents of ethyl acetate $(67.8{\sim}89.1%)$ was more than those of any ether component followed by hexadecanoic acid $(1.21{\sim}12.00%)$ and tetramethylpyrazine $(0.06{\sim}12.30%$).

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.102-109
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• 2014

Crab-like flavoring base (CFB) was made from a concentrated snow crab cooker effluent (SCCE) containing five food additives (proline, glycine, arginine, methionine, fructose) using reaction flavor technology (RFT). The volatile flavor compounds in CFB were compared between raw (SCCE) and control (without food additives) samples using solid phase microextraction (SPME) and gas chromatography with mass selective detector. A total of 74 compounds were detected in all samples (30 raw samples, 34 control samples, 55 CFB samples). A total of 22 nitrogen-containing compounds, including 19 pyrazines and 3 pyridines, were formed through RFT and increased 27 times compared to the control. Dimethyl trisulfide and dimethyl disulfide were predominant sulfur-containing compounds that increased through RFT, while aromatic compounds decreased through RFT. Seven compounds, tetramethylpyrazine, 2-ethyl-3,5,6-trimethylpyrazine, 2,3,5-trimethyl-6-(3-methylbutyl)pyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,5-dimethyl-3-(3-methylbutyl)pyrazine, 2-ethyl-3,6-dimethylpyrazine, and 2-decanone potentially have a role in CFB odor by Pearson's correlation analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.3
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• pp.454-458
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• 1995

Alkylpyrazines in snow crab cooker effluent(SCCE) and effluent concentrate(EC) were quantitatively analyzed and compared by simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry(SDE/GC/MS). A total of 11 pyrazines were identified in both SCCE and EC. Amounts of tetramethylpyrazine, 2,5-dimethylpyrazine, trimethylpyrazine, and 2,6-dimethylpyrazine were 23.0, 21.1, 13.8, and 13.3 times higher, respectively, in EC than those in SCCE. The total amount of pyrzines in EC (1664.0${\pm}$171.1ng/g) was 8.1 times higher than that in SCCE(204.5${\pm}$32.2). The compounds, ethylpyrazine and 2-ethyl-3,6-dimethylpyrazine, were only detected in EC.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.414-418
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• 2008

Volatile compounds in Omangdungi (Styela plicata)-Doenjang (soybean paste) stew were analyzed using solvent-assisted flavor evaporation/gas chromatography/mass-selective detection/olfactometry (SAFE/GC/MSD/O) and aroma extract dilution analysis (AEDA). The GC/O analysis detected 37 volatile compounds, of which 32 were positively identified, and included 9 aldehydes, 5 alcohols, 4 aromatic hydrocarbons, 4 ketones, 3 esters, 3 N-containing compounds, 2 acids, 1 S-containing compound, and 1 furan. Nine aroma-active odorants ($\log_3FD{\geq}3.0$) in the sample included six compounds derived from Doenjang (3-methyl(thio)propanal, tetramethylpyrazine, 4-vinyl-2-methoxyphenol, 2-acetylpyrrole, butyric acid, and 2-methoxyphenol) and three compounds from Omangdungi (2-acetyl-2-thiazoline, 9-decanol, and 6-decenol). Three compounds derived from Omangdungi (9-decanol, 6-decenol, and 6-nonenol) were thought to enhance the seafood-like flavor of Omangdungi-Doenjang stew.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.557-565
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• 1992

Volatile components of domestic Meju and Doenjang were extracted by simultaneous steam distillation extraction, and analyzed by GC-MS. Sixty-four kinds of compounds were identified from neutral fraction. The contents of pentanal, hexanal and 1-octen-3-ol were high in cooked soybean while those of 3-methylbutanal and 1-butanol were high in Meju. In the case of Doenjang, so many compounds including acetic acid, ethylester were identified which was not appeared in Meju. The main compounds in Meju were 3-methyl-1-butanol, 2-furancarboxyaldehyde, 1-octen-3-ol, benzeneacetaldehyde, methyloctadecadienoate and methyloctadecenoate. Of the eleven compounds identified from basic fraction, the contents of 2,6-dime-thylpyrazine, trimethylpyrazine and tetramethylpyrazine were high in Meju and Doenjang. Nine kinds of compounds were identified from phenolic fraction and appeared that 4-vinylphenol and p-ethylguaiacol were major compounds in Meju and Doenjang. Fifteen kinds of volatile compounds were contained in acidic fraction. Only four acidic compounds were identified in cooked soybean and Meju, but in Doenjang ten compounds were identified which did not appeared in other samples. Among them pentadecanoic acid was major compound.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.191-199
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• 2019

We inoculated different combinations of three starter candidates, Bacillus licheniformis, Staphylococcus succinus, and Tetragenococcus halophilus, into sterilized soybeans to predict their contributions to volatile compound production through soybean fermentation. Simultaneously, we added NaCl to soybean cultures to evaluate its effect on the volatile compounds profile. Cells in soybean cultures (1.5% NaCl) nearly reached their maximum growth in a day of incubation, while cell growth was delayed by increasing NaCl concentrations in soybean cultures. The dominance of B. licheniformis and S. succinus in the mixed cultures of three starter candidates switched to T. halophilus as the NaCl concentration increased from 1.5% to 14% (w/w). Seventeen volatile compounds were detected from the control and starter candidate-inoculated soybean cultures with and without the addition of NaCl. Principal component analysis of these volatile compounds concluded that B. licheniformis and S. succinus made major contributions to producing a specific volatile compound profile from soybean cultures where both species exhibited good growth. 3-Hydroxybutan-2-one, butane-2,3-diol, and 2,3,5,6-tetramethylpyrazine are specific odor notes for B. licheniformis, and 3-methylbutyl acetate and 2-phenylethanol are specific for S. succinus. Octan-3-one and 3-methylbutan-1-ol were shown to be decisive volatile compounds for determining the involvement of S. succinus in the soybean culture containing 7% NaCl. 3-Methylbutyl acetate and 3-methylbutan-1-ol were also produced by T. halophilus during soybean fermentation at an appropriate level of NaCl. Although S. succinus and T. halophilus exhibited growth on the soybean cultures containing 14% NaCl, species-specific volatile compounds determining the directionality of the volatile compounds profile were not produced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.738-746
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• 2006

Aroma compounds in four different Byeolmijang made from optional ingredient addition were extracted by SDE (simultaneous steam distillation extraction) and analyzed with GC (gas chromatography) and GC/MS (mass-spectrometry). The major aroma compounds in the four different Byeolmijang during aging were 1-octene-3-ol, hexanal, benzeneacetaldehyde, benzaldehyde, fufural, pyrazine, furan and phenol type compounds. Generally, benzeneacetaldehyde, benzaldehyde, fufural and phenol type compounds were increased during aging. On the other hand, 1-octen-3-ol, hexanal and furan were decreased during aging. Furfural, 2-furanmathanol and benzeneacetaldehyde in Sanghwangjang, 3-methyl-1-butanol, phenol and 1H-indole in Mujang, hexanal, 1-octen-3-ol and 2,4-decadienal in Bizijang and hexanal, tetramethylpyrazine and 2-methoxy-4-vinylphenol in Jigeumjang were identified as major aroma compounds, respectively. Generally, the major aroma compound in four different Byeolmijang with optional ingredient was similar with control and pyrazine, furan and phenol type compounds were decreased to addition with optional ingredient. The major aroma compound in Sanghwangjang with optional ingredient (onion) were 1-hexanol and 2,5-dimethylthiophene and the major aroma compounds were 1,2,4-trithiolane and 2-buthyl-2-octenal in Mujang with optional ingredient (Letinus edodes). Furfural, benzaldehyde, benzeneacetaldehyde, 1,2,4-trithiolane and lenthionine were detected in Bizijang due to the addition of powdered Letinus edodes. Linaool and ${\beta}-lonone$ were detected in Jigeumjang due to the addition of powdered red pepper.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.351-360
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• 1992

In order to improve the qualities of Doenjang were investigated on the enzyme activity in the koji and changes in chemical composition, flavors and sensory envaluation of Doenjang which were prepared with Rh. delemar koji, Asp. oryzae koji and traditional Meju with mixed koji and soybean as the ratio of optimum mixture. Asp. oryzae koji was indicated highest activities ${\alpha}$ and ${\beta}-amylase$ as 312 mg/ml, 235 mg/ml while Rh. delemar the lowest activities as 16 mg/ml, 38 mg/ml in aging for 40 days amino type ntrogen was the highest in the Asp. oryzae and Rh. delmear mixture koji(D group), Asp. oryzae(A group), and Asp. oryzae koji and Rh. delemar koji(C group) as 460 mg%, 440 mg% and 426 mg% in aging for 40 days. The main flavor components of Doenjang were detected as fellows phenol-2-kmethoxy, 4H-pyran-4-one-3-hydroxy-2-methyl, benzenthanol, 1-octan-3-ol, tetra-methyl pryrazine, 1,3,6 cyclooctatrien. Asp. oryzae(A) and Asp. oryzae koji with Rh. delemar koji mixture(C), group were the most excellent in taste, flavor color for fermented Doenjang at 40 days.