• Analytical Science and Technology
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• v.35 no.2
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• pp.53-59
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• 2022

Mugwort (Artemisia montana), which is a perennial plant mainly distributed throughout Northeast Asian regions, has been used as a preferred source of various foods and traditional medicines in Korea. In particular, as essential oils extracted from mugwort were reported to be biologically active, its steam distillate has been widely used to treat various conditions, such as itching, hemorrhoids, and gynecological inflammation. Therefore, efforts have been devoted to develop effective methods for the collection of bioactive essential oils from mugwort. In this study, five mugwort extracts were obtained using different extraction conditions, namely, 6 % ethanol at room temperature and at 80 ℃, pure ethanol, n-hexane, and an adsorbent resin. To evaluate the five extracts of mugwort, area-under-the-curve values (AUCs), chemical profiles, and major bioactive essential oil contents were investigated using gas chromatography-mass spectrometry (GC-MS). An overall assessment of the volatile components, including essential oils, in the five extracts was conducted using AUCs, and the individual essential oil in each extract was identified. Furthermore, the four major essential oils (1,8-cineole, camphor, borneol, and α-terpineol), which are known to possess anti-microbial and anti-inflammatory activities, were quantified using authentic chemical standards. Based on the evaluation results, pure ethanol was the best extractant out of the five used in this study. This study provides evaluation results for the five different mugwort extracts and would be helpful for developing extraction methods to efficiently collect the bioactive oil components for medical purposes using chemical profiles of the extracts.

• Korean journal of food and cookery science
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• v.11 no.4
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• pp.386-395
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• 1995

This study was carried out to investigate the volatile constituents change according to extraction methods, parts and heating methods. The research results are as follows: 23 kinds of components were extracted by steam distillation method; 8 by head space method; 16 by ether extraction method; 9 by Tenax-GC. This fact indicated that volatile constituents differ depending upon the extracting method. When the volatile constituents were extracted by steam distillation method and analyzed by GC-MSD, the content of the volatile constituents was 41.71 mg％ in the stem and 85.37 mg％ in the leaf. A total of 23 components - 14 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol- were detected in the stem. A total of 31 components - 21 kinds of hydrocarbon, 5 of aldehyde, 4 of alcohol and 1 of ester were detected in the leaf. The leaf had comparatively more varied volatile constituents than the stem. In the stem, the octanal content was highest and the contents of limonene, sabinene, -terpinene and -myrcene were higher; in the leaf, the content of octanal was highest and the contents of isobicyclogermacrene, limonene, -farnesene, undecaethiol, -terpinene, sabinene, elemene, -myrcen were higher. These were the major volatile constituents of the water d.opwort. The volatile constituent formation changed as the water dropwort was heated. The volatile constituents of the water dropwort heated in 1000 $m\ell$ were the most similiar to those of the raw water dropwort, and volatile constituent content was highest.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.209-214
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• 1998

A thermodynamic simulation method is developed for the process design and the performance evaluation of the gas turbine in IGCC power plant. The present study adopts four clean coal gases derived from four different coal gasification and gas clean-up processes as IGCC gas turbine fuel, and considers the integration design condition of the gas turbine with ASU(Air Separation Unit). In addition, the present simulation method includes compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. The present prediction results show that the efficiency and the net power of the IGCC gas turbines are seperior to those of the natural gas fired one but they are decreased with the air extraction from gas turbine to ASU. The operation point of the IGCC gas turbine compressor is shifted to the higher pressure ratio condition far from the design point by reducing the air extraction ratio. The exhaust gas of the IGCC gas turbine has more abundant wast heat for the heat recovery steam generator than that of the natural gas fired gas turbine.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.847-852
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• 2009

Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damange, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle inside feed-water heater installed downstream of the turbine extraction stream line. At that point, the extract steam from the turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows to reverse direction after impinging the impingement baffle, the shell wall of feedwater heaters may be affected by flow-accelerated corrosion. In this paper, to compare wall thinning range according to change entrance nozzle diameter and position with reference numerical analysis model's wall thinning range, various numerical analysis models applied. In case of changing diameter, four different diameter is applied. And a side of nozzle position, two different position-vertical type and parallel type-is applied. And then this paper describes operation of numerical analysis which is composed similar condition with real feed water heater. In conclusion, this study shows effective design for shall wall thinning by changing nozzle diameter and position.

• Journal of the Korean Society of Food Culture
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• v.12 no.3
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• pp.265-274
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• 1997

This study was conducted in ordor to find the most suitable conditions for producing the Doenjang with optimal odor compound contents. Three sample groups with the different preparing methods -Doenjang that has not gone through the soy sauce separation process (Doenjang A), Doenjang that has gone through the soy sauce separation process; Meju-20% salt water ratio of 1 : 4 (Doenjang B), and that with the ratio of 1.3 : 4 (Doenjang C)- were tested during different ripening periods. Odor compound contents were analyzed through Solvent Extraction Method and Simultaneous Steam Distillation Extraction (SDE). The number of odor compounds was greatest in Doenjang A and during the mid to late stage in each groups. In the sensory evaluation of Doenjang odors, Doenjang A received the highest scores in the categories of overall preferences, while Doenjang C got the lowest scores. Individual odor didn't vary significantly during ripening periods, but the overall odor and taste preference was highest in the samples ripened for 75 to 120 days. Stepwise multiple regression analysis of major odor compounds of Doenjang revealed that benzeneacetaldehyde is the major explanatory variable for offensive odor. Benzeneethanol, 3-methylthio-propanal and 4-methyl-phenol are the explanatory variables for salty odor, nutty odor and rancid odor, respectively. Odor compounds that contribute to the overall odor preference varied from the compounds that affect the taste preference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.775-783
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• 2015

This study was carried out to investigate the physicochemical properties and volatile ingredients of Jeju Apple mango subjected to different extraction methods and GC/MS. The crude protein, fat, and ash contents were $0.22{\pm}0.01$, $0.09{\pm}0.00$, and $0.27{\pm}0.02%$, respectively, and contents of free sugar increased in the order of sucrose, fructose, and glucose, whereas maltose, lactose, and galactose were not detected. The numbers of volatile flavor compounds obtained by the SE (solvent extraction), SDE (simultaneous steam distillation extraction), and SPME (solid-phase micro-extraction) methods were 51, 59, and 71, respectively. The percentages of extracted volatile flavor compounds in mango were 11.44, 15.68, and 73.54% by the SE, SDE, and SPME methods, respectively. The most abundant compounds found in Jeju Apple mango were terpenes and their derivatives, which accounted for 44.49~94.57% of total volatiles obtained. SPME method was considered to be the most effective extraction method in terms of the numbers of detected compounds and their amounts. ${\delta}$-3-Carene was identified as the dominant compound in mango, whereas ${\alpha}$-phellandrene, ${\gamma}$-terpinene, trans-${\beta}$-ocimene, ${\alpha}$-terpinolene, limonene, ${\alpha}$-pinene, and furaneol were the next important compounds.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.669-674
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• 2008

Zanthoxylum schinifolium and Zanthoxylum piperitum A.P. DC. belong to the Rutaceae family and are perennial, aromatic, and medicinal herbaceous plants. In this study, their aroma compounds were isolated by steam distillation extraction using a Clevenger-type apparatus, and then further analyzed by gas chromatography (GC) and gas chromatograph/mass spectrometry (GC/MS). The yields of the essential oils from Z. schinifolium and Z. piperitum AP. DC. were 2.5 and 2.0%(w/w), respectively, and the color of their oils was quite similar, a pale yellow. From the distilled oil of Z. schinifolium, 60 volatile compounds which make up 87.24% of the total composition were tentatively identified, with monoterpenes predominating. $\beta$-Phellandrene (22.54%), citronellal (16.48%), and geranyl acetate (11.39%) were the predominantly abundant components of Z. schinifolium. In the essential oil of Z. piperitum AP. DC., 60 volatile flavor components constituted 94.78% of the total peak area were tentatively characterized. Limonene (18.04%), geranyl acetate (15.33%), and cryptone (8.52%) were the major volatile flavor compounds of Z. piperitum A.P. DC.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.394-399
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• 1988

Volatile components of Ixeris dentata and Amaranthus mangostanus, Korean wild vegetables, were collected by Steam Distillation-Extraction(SDE) method. Essential oils were analyzed by gas chromatography(GC)and combined gas chromatography-mass spectrometry(GC-MS). Sixty one components, including 13 alcohols, 9 esters, 12 aldehydes, 6 ketones, 9 hydrocarbons, 6 acids, 3 phenols and 3 miscellaneous ones were confirmed in Ixeris dentata. Fifty six components, including 15 alcohols, 5 esters, 13 aldehydes, 8 ketones, 3 hydrocarbons, 9 acids and 5 miscellaneous ones were confirmed in Amaranthus mangostanus.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.841-846
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• 2009

Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed downstream of the high pressure turbine extraction stream line inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. This paper describes operation of experience and numerical analysis composed similar condition with real high pressure feedwater heater. This study applied several impingement baffle plates to feedwater heater same as previous study. In addition, it shows difference of pressure distribution and value between single phase and two phase based on experience and numerical analysis.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.674-680
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• 1997

Volatile flavor components of fresh, shady air dried, and presteamed shady air dried Chamnamul (Pimpinella brachycarpa) were collected by simultaneous steam distillation-extraction method, and essential oils were analyzed by gas chromatography-mass spectrometry (GC/MS). Twenty five, 17 and 23 volatile flavor components were identified in essential oils extracted from the fresh, shady air dried, and presteamed shady air dried Chamnamul samples, respectively; however, the kinds of individual components and its percent content of the total volatiles were varied depending on samples. The principal components of Chamnamul were isobutanal, trans caryophyllene, trans ${\beta}$-farnesene, and ${\alpha}$-selinene. Terpenoid compounds reached 44.11%, 33.91% and 72.63% respectively in fresh, shady air dried, and presteamed shady air dried Chamnamul.