• Food Science and Preservation
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• v.13 no.2
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• pp.269-272
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• 2006

Aroma compounds in chungkukjang with Astragalus membranaceus (Hwangki) were extracted by the simultaneous distillation and extraction (SDE), headspace and solid phase microextraction (SPME), and aroma compounds obtained by this method were identified with GC-MS. Thirty compounds were identified, including six ketones, eight alcohols, three heterocyclic compounds, three aldehydes, five hydrocarbones and five other compounds. Major aroma compounds were identified as 3-hydroxy-2-butanone, 2-furanmethanol, 2-methoxy-4-vinylphenol, and 4-vinylphenol in SDE, 2,3-butanedione, 3-hydroxy-2-butanone, ethanol, 2,6-dimethyl pyrazine and acetic acid in headspace and acetone, ethanol, 2,5-dimethyl pyrazine, tetramethyl pyrazine and acetic acid in SPME. The content of pyrazines identified in headspace and SPME methods was higher than that of SDE method, and the content of pyrazines containing 2,5-dimethyl pyrazine, 2,6-dimethyl pyrazine and tetramethyl pyrazine in chungkukjang was higher than that of Hwangki chungkukjang.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.88-91
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• 1999

Aroma components of tea processed from Korean chicory roots were isolated and identified. The model system of amino-carbonyl reaction was carried out to study the formation mechanism of aroma compounds of chicory tea during manufacturing process. The concentration extracts from chicory tea and model system were analyzed and identified by gas chromatography(GC) and GC-mass spectrometry. Twenty-nine compounds, including pyrazines, furans, acids, alcohols, pyrroles and lactones were isolated and identified in chicory tea. The main compounds were pyrazines including methyl pyrazine, 2,5-dimethyl pyrazine, 2, 6-dimethyl pyrazine, 2-ethyl-6-methyl pyrazine, 2-ethyl-3-methyl pyrazine, thrimethyl pyrazine, 3-ethyl-2-5-dimenthyl pyrazine, 5-ethyl-2-3-dimenthyl pyrazine, and 2-acetyl-3-methy pyrazine and pyrroles including acethl pyrrole and formlyl pyrrole ; and furans including furfural , acetyl furan, 5-methyl furan, 5-methyl furfuralm, and furfuryl alcohol. These pyrazine compounds of a roasted and nutty aroma may be important contributors to the flavor of chicory tea. The aroma concentrate of model system also had a roasted and nutty aroma and the main compounds were methyl pyrazine, 2, 5-dimetyl pyrazine, 2, 6-dimethyl pyrazine and trimethyl pyrazine.

• 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.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.151-158
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• 1997

Burley leaf tobacco extracts has been heated at loot for 2 hours and changes in non-volatile fructosazines and volatile components were investigated. Major changes for the heat treatment with corn syrup of burley leaf tobacco extracts were as follows, increases in the contents of 2,5-deoxyfructosazine and 2,5-fructosazine that is produce for the heating reaction of sugar and ammonia, production of pyraEine compounds, such as 2,6-dimethyl pyrazine,2,4-dimethyl pyrazine, ethrnyl pyrazine, methylethyl pyraxine, trimethyl pyrazine, 2-ethenyl-5-methyl pyrazine, 2-acetyl parazine and 2-acetyl-3-methyl pyrazine, increases in the content of furfuryl alcohol derived from sugar degrad ation, production of 2,5-dimethyl-4-hydroxy-3(2H)-furanone and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one derived from thermal degradation of Amadori compounds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.370-374
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• 1989

Volatile components in natural and basic fraction of the steam distillation extraction method from squid during processing were analysed by GC and GC-MS equipped with a fused silica capillary column. Thirty eight compounds were identified; they were 31 compounds from neutral, 7 compounds from basic fraction. The main components flavor of squid were 3-methylthiophene, 2-methyl-2-hexanthiol, 1-penten-3-ol, 3-penten-2-ol, 3-ethyl-1,4-hexadiene, 1-hydroxy-2-propanone, hexenal and benzaldehyde etc.. Especially, (E, E)-3,-5-octadecanal were detected during the boiled. 2,5-dimethyl pyrazine, 2-ethyl-6-pyra-zine, 2,3,5-trimethyl pyrazine and 2-ethyl-3,5-dimethyl pyrazine basic compounds, which have respectively a burnt and roasted odor, are considered to be important for the characteristic basic fraction of squid.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.9-13
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• 2007

In this study, sesame oils and sesame meals(A, B) were obtained from roasted sesame at $200^{\circ}C$ and $220^{\circ}C$, respectively. The total volatile component(VC) contents of these samples(A, B) were as follows : The sesame oils had 1,397.1 ppm and 1,518.8 ppm, and the sesame meals had 663.2 ppm and 775.3 ppm for samples A and B, respectively : sesame flavor was16,507.9 ppm, The major VCs in the sesame oils were pentane, 2-butanone, pyrazine, methylpyrazine, 2,5- and 2,6-dimethyl pyrazine, furfuryl alcohol, guaiacol and 4-vinylguaiacol. The pyrazine contents of the seasame oils were 834.4 ppm and 816.4 ppm for samples A and B, respectively. The major VCs in the sesame meals were 2-butanone, hexanal, pyrazine, methyl pyrazine, 2,6-dimethyl pyrazine, furfuryl alcohol, and so forth. For artificial sesame flavor, the total VC content was 16,507.9 ppm, and the major VCs were 2-butanone, guaiacol, and 4-vinylguaiacol. Approximately 35.02% of the total VC content of sesame flavor was composed of 2-butanone, guaiacol, and 4-vinylguaiacol, and these constituted more than 1,000 ppm of its total VC content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.332-341
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• 2007

The purpose of this study was to investigate the change of flavor compounds of freeze-dried garlic and garlic roasted with soybean oil and sesame oil. Freeze-dried garlic and ground raw garlic roasted with oils was prepared at $180^{\circ}C$ for 5 minutes. Volatile compounds of garlic samples were obtained by Likens-Nickerson distillation/solvent extraction and identified by GC and GC/MS. Sulfur compounds, methyl allyl sulfide, diallyl sulfide, methyl allyl disulfide, dimethyl trisulfide, diallyl disulfide, methyl allyl trisulfide and diallyl trisulfide were the major volatile in garlic flavor which was more than 98% of the total volatile compounds. The total amount of sulfur compounds in freeze-dried garlic roasted with soybean oil was decreased to 20% compare to that of garlic flavor; however, 10 pyrazines such as 2-methyl pyrazine, 2,6-dimethyl pyrazine, 2-ethyl-5-methyl pyrazin and 3-ethyl-2,5-dimethyl pyrazine which were not originated from both freeze-dried garlic and soybean oil were identified. They might be generated from thermal interactions of sugars and nonvolatile flavor precursors of garlic. In freeze-dried garlic roasted with sesame oil, the amount of diallyl sulfide, methyl allyl disulfide, dimethyl trisulfide increased whereas diallyl disulfide completely disappeared. The amount of two cyclic compounds 3,4-dihydro-3-vinyl-1,2-dithiin and 2-vinyl-4H-1,3-dithiin, which were artifacts from allicin, increased in roasted garlic with sesame oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.384-388
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• 2000

본 연구는 cocoa mass를 마이크로파 roasting하여 그 향기성분의 변화를 pyrazine류를 중심으로 살펴보는 한편 상법으로 roasting한 경우와 비교하고자 하였다. 마이크로파 roasting은 110,120,130,140,15$0^{\circ}C$의 온도에서 20분 및 30분 동안 행하였고 상법의 경우는 14$0^{\circ}C$에서 30분간 roasting하였다. Roasting한 시료를 연속수증기증류추출법으로 추출하고 농축한 후 GC와 GC/MS로 향기 성분을 분석하였다. 마이크로파 roasting의 경우 5분만에 14$0^{\circ}C$에 도달한 후 그 온도를 잘 유지하였으나, 상법의 경우 25분이 경과되어서야 14$0^{\circ}C$에 도달되었다. Roasting 한 시료의 향기성분으로 2,6-dimethyl pyrazine, 2,3,5-trimethyl pyrazine, 2,3,5,6-teramethyl pyrazine, 5-methyl fufural, 2-methyl-6-propyl pyrazine 등이 확인되었다. Roasting 온도가 증가함에 따라 dimethyl-, trimethyl-, tetramethyl pyrazine류가 증가하였고, tetramethyl pyrazine은 15$0^{\circ}C$ 20분 roasting의 경우 현저하게 증가하였으나, 30분 동안 roasting한 경우 14$0^{\circ}C$에서 증가하였다가 15$0^{\circ}C$일 때는 감소하였다. 그러나 적정 roasting 지표인 di/tri, di/tetra pyrazine의 비율은 1 이하를 보임으로써 마이크로파 roasting이 cocoa mass의 향기 발현에는 부족한 것으로 나타났다.

• 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.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.157-163
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• 1987

Changes in the odor components of Sergia Lucens during fermentation were studied by simultaneous distillation and extraction method. Forty seven components were identified by GC and GC-MS. Major cooked odor components of raw material were alkyl pyrazines and thialdine. Alkyl pyrazines, furfuryl alcohol, isoamyl alcohol and sulfide compounds, such as dimethylsulfide and dimethyltrisulfide increased during the period of fermentation. On the other hand, thialdine content decreased as the period of fermentation was extended. Sensory evaluation of cooked Sergia Lucens odor was carried out by GC-sniff analysis. The odors of GC effluents at the sniffing port were sniffed in order to find out the key compound of cooked Sergia Lucens odor components. The results of the GC-sniff analysis indicated that 2,5-dimethylpyrazine, 2,6-dimethylpyrazine and 2,3-dimethylpyrazine had dried or roast shrimp-like odor and thialdin had dried small sardine-like odor. The result showed that pyrazines and thialdine could play an important role in the formation of cooked Sergia Lucens odor.