• Korean journal of applied entomology
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• v.42 no.1
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• pp.9-13
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• 2003

Cuticular hydrocarbons of antenna, legs and wings from two species of honeybee worker of Apis mellifera L. and Apis cerana F. can be analyzed directly with gas chromatograph and GC/MS without solvent extraction. The saturated hydrocarbons identified in selected part of both species were nC22, nC23, nC25-nC3O, nC32 and nC34 except nC24. Two saturated hydrocarbons, nC26 (23.0-42.6%) and nC28 (16.8-54.8%), were major compounds in both species and others were minor compounds. A. mellifera can be distinguished from A. cerana F. by having higher proportion of nC30, nC32 and nC34 by having lower proportion of nC25 from three selected part of both species.

• Food Science and Preservation
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• v.30 no.3
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• pp.492-501
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• 2023

In this study, we wanted to understand the impact of different decaffeination processes on aroma compounds of coffee. Therefore, we analyzed differences in physical characteristics and volatile aroma compounds profiles of regular coffee (RC), Swiss water process decaffeinated coffee (SWDC), and supercritical CO₂ decaffeinated coffee (SCDC) after roasting the coffee beans. The electronic nose analysis identified RC and SCDC as different groups which indicates that these groups volatile aroma compound compositions were different. The principal component analysis of volatile compound patterns identified using an electronic nose indicated that there was a large difference in volatile compounds between RC, which was not decaffeinated, and both decaffeinated SWDC and SCDC. The major aroma compounds of RC, SWDC and SCDC were propan-2-one and hexan-2-one which are ketone, and hexanal and (E)-2-pentenal which are aldehyde and 3-methyl-1-butanol which is an alcohol. After roasting, the composition of major volatile compounds appearing in the beans was similar, but the relative odor intensity was different. We identified 28 volatile aroma compounds from RC, SWDC, and SCDC using headspace-solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS), and analyzed 10 major compounds that were present in high abundance, including furfural, 2-furanmethanol, 2,5-dimethylpyrazine, and 2-ethyl-3-methylpyrazine.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.22-22
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• 2021

큰졸방제비꽃(Viola kusanoana)의 엽록체 DNA 염기서열을 밝히고자 차세대염기서열분석법(NGS)을 이용하여 분석하였다. 재료는 경상북도 울릉군 나리분지에 자생하는 개체의 잎을 사용하였다. 염기서열 분석결과, 총 길이는 158,644 bp 였고, GC함량은 36.3%로 분석되었다. 구간별로는 LSC (Large single copy)지역이 86,999 bp (GC content: 33.9%)였고 SSC (Small single copy)지역은 17,439 bp (GC content: 29.9%)으로 분석되었으며 IR (Invertied repeats)지역은 27,103 bp (GC content: 42.2%)로 확인되었다. 유전자는 protein coding gene 77개, tRNA gene 30개, rRNA 4개 등 총 111개로 이는 선행 연구된 제비꽃속 8개 분류군과 유전자의 순서와 방향이 모두 일치하였다. 이를 통해 제비꽃속의 엽록체 게놈의 유전자는 상당히 보존되어 있음을 확인하였다.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.100-106
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• 2005

To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.1-5
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• 1992

The concentrations of tocopherols and lipids, and compositions of fatty acids in the seeds of thirteen pulse plants, which are used for the raw materials of our traditional food as well as for the typical nutrients in Korea, were analyzed by HPLC and GC. The beans showed great differences of the tocopherol concentrations from 4.74 to 44.05 mg/100g, which were in the order of ${\gamma}->{\delta}->{\alpha}-tocopherol$ with the exception of the order of ${\delta}->{\gamma}->{\alpha}-tocopherol$ in jeock sodu and gal sodu of azuki bean. The contents of lipids were also remarkably different as 0.53 to 20.96%. Especially, the beans having from 15.78 to 20.96% of lipid contents showed high composition ratios of unsaturated fatty acid between 85.6 to 88.2%, of which the contents of linoleic acid were the highest as 56.0 to 58.6% of the total fatty acids, and also showed comparatively high concentrations of tocopherols as 23.2 to 44.05 mg/100g. There were significantly positive correlation between ${\gamma}-tocopherol$ and unsaturated fatty acids.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.794-799
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• 2008

The effect of ultrasonication on the sulforaphane analysis in cruciferous vegetables was investigated by GC/MS. The ultrasonication of the analysis samples was carried out in dichloromethane as a solvent, which was followed by concentration in nitrogen gas, and the analysis of sulforaphane was performed using selective ion monitoring (SIM) at m/z 72, 160, 55 and 114. The content of sulforaphane was the highest in the extract of broccoli (149 ppm), and followed by cabbage (67.9 ppm) and radish (35.4 ppm). When the vegetable samples were shaked after ultrasonication, the extraction efficiency of sulforaphane was 2.7-fold enhanced, compared to the extraction by shaking. The result suggested that pretreatment including sonication can be used fer improving the extraction efficiency of sulforaphane.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1734-1742
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• 2011

Conjugated linolenic acid (CLnA) and conjugated linoleic acid (CLA) are positional geometric isomers with three and two double bonds, respectively. In this study, perilla seed oil containing 60% ${\alpha}$-linolenic acid (C18:3) and 30% linoleic acid (C18:2) was used as a reaction substrate. After the perilla seed oil was hydrolyzed, conjugated fatty acids were synthesized using different reaction parameters, such as reaction time and concentration of sodium hydroxide. As a result, CLnA, CLA, and other newly synthesized conjugated isomers were present at levels of 14.5%, 14%, and 42.2%, respectively, when the reaction was performed with 20% NaOH, at $180^{\circ}C$, and for 1 hr. The results of GC-MS and fourier transform infrared spectroscopy (FT-IR) showed that CLnA isomer of cis-9, trans-11, and trans-13 octadecatrienoate, CLA isomer of cis-9, trans-11, and trans-10, cis-12 octadecadienoate, and other conjugated isomers were produced. Using urea, ${\alpha}$-linolenic acid could be concentrated from perilla seed oil hydrolysate. After concentration by urea, the concentration of ${\alpha}$-linolenic acid reached about 70%. After alkaline-isomerization was performed on the urea fraction containing 70% ${\alpha}$-linolenic acid, the content of CLnA increased up to 16.6%.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.503-508
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• 2009

The principal objective of this study was to evaluate the physicochemical properties and volatile compound contents of Moju acquired from 12 restaurants in Jeonju. The alcohol contents were lower than 2.1%, and the pH values ranged from 3.85 to 4.38. Total acidity, $^{\circ}Bx$, and UV absorbance values differed among the samples according to the type of side materials added. Reducing sugar contents were found to be substantially superior to other commercial takju variants. Malic and lactic acid contents were higher than the contents of other organic acids, and the free sugar contents were as follows: maltose>glucose>fructose. Overall, the high b (yellowness) and cP values were attributable to the turbid yellow and heavy condition of the samples. The volatile compound contents of Moju were analyzed via GC and GC/MSD. 30 components were identified, including 3 alcohols, 12 esters, 7 hydrocarbons, and 4 aldehydes. Among the alcohol compounds, benzeneethanol levels were higher than the levels of isoamyl alcohol. Ethyl caprate, ethyl palmitate, and ethyl linoleate, which were fundamentally attributable to origin liquor, were highest among the 12 esters. (E)-cinnamaldehyde, which was the most abundant among 7 hydrocarbons, and (E)-cinnamyl acetate contents were attributed to the presence of cinnamon, a common supplement in the processing of Moju.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.352-357
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• 2003

Volatile flavor compounds Angelica gigas Nakai and Angelica acutiloba Kitagawa were extracted by SDE (simultaneous steam distillation & extraction) using the mixture of n-pentane and diethylether (1:1, v/v) as an extract solvent and analyzed by GC-FID and GC-MS. The amount of essential oils of top part and root in Angelica gigas were obtained in 0.063% (v/w) and 0.389% (v/w) yields as a fresh weight base, respectively. The main compounds in top parts and the root were identified as nonane (7.51% and 24.49%, respectively), ${\alpha}-pinene$ (14.64% and 31.75%), limonene+${\beta}-phellandrene$ (14.01% and 9.66%), ${\gamma}-terpinene$ (7.85% and 1.20%), germacrene-d (5.85% and 0.22%), (E,E)-${\alpha}-farnesene$ (6.05% and 1.40%), ${\beta}-eudesmol$ (5.26% and 1.84%). Although these compounds were present in both parts. The results showed large differences in. the concentrations of them much varied. The amount of essential oils stem and leaf obtained (0.068% and 0.127% in A. gigas) and (0.153% and 0.243% in A. acutiloba) yields as a fresh weight base, respectively. More than 18 and 32 components in stem and leaf have been identified, which of main components in A. gigas were ${\alpha}-pinene$, myrcene, limonene, germacrene-d, eudesmol and butylphthalide, but germacrene-d and butylphthalide contents were also different in stem and leaf. And more than 21 and 32 components in A. acutiloba were ${\gamma}-terpinene$ and butylphthalide. Volatile compounds were very different in both species.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.313-321
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• 2004

Separation-concentration of sulfur containing heterocyclic compounds(SCHC) from many reaction meat flavors manufactured with Maillard reaction was carried out. Profile of SCHC was identified and analyzed by GC and GC-MSD. The results were as follows. 1. Profile of SCHC could be identified 7 kinds thiazole and 11 kinds thiophene, the major produced compounds were thiophene, thiazolidine, 4-methyl-5-thiazole ethanol. 2. In the case of SCHC, relationship between changes of reaction conditions and the kind of produced components were as same, but produced amounts appeared the difference. Producing amount of complexed SCHC and caramellike note as well as oxygen containing heterocyclic compounds were high level more than high reaction temperature and long time reaction period. 3. Producing ratio of comparative simple structural SCHC were the highest level at reaction conditions of moisture content 50%, reaction temperature 100$^{\circ}C$ and reaction time 2 hours. Reaction conditions for the revelation of reaction meat flavor were below 110$^{\circ}C$ and less than 2 hours. 4. Relationship between moisture content and reaction temperature as well as reaction time had very relative relation. From the change of moisture content and reaction conditions could be obtained the simultaneously profile. Signal presentation for production of reaction meat flavor could be from extraction-separation-concentration of SCHC through simplification of raw-materials in the flavor and seasoning food industry.