• Food Science and Preservation
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• v.15 no.4
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• pp.524-531
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• 2008

To investigate tea prepared from Ixeris dentata root, color, and levels of free sugars, organic acids, cynaroside, total polyphenolics, and free amino acids were investigated using various thermal processing methods. These included natural drying(ND), hot-air drying(HAD, $75^{\circ}C$), hot-air drying after steam(HADS, steaming at $95^{\circ}C$ for 30 min) and roasting after hot-air drying(RHAD, roasting at $140^{\circ}C$ for $2{\sim}3$ min). Total free sugars, organic acids, cynaroside, and free amino acids contents were highest after ND treatment. Total polyphenolics was highest after RHAD processing. The level of cynaroside, a principal component of Ixeris dentata root, was significantly decreased by HADS. The major free sugars were fructose, glucose and sucrose. Succinic acid was prominent among organic acids, and was present at 2.25%(v/v) after ND treatment. The lightness(L), redness(a), and yellowness(b) of all dried Ixeris dentata root powders were best after RHAD treatment, but analysis of the leaching liquids after hot water treatment yielded variable results. Lightness and redness were the highest after RHAD and yellowness was the highest after ND treatment. Overall, the RHAD drying method was found to be superior to other methods, in sensory evaluation tests.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.641-647
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• 1997

Volatile flavor components in whole edible portion, stem and leaf of fresh angelica (Angelica keiskei Koidz) were extracted by SDE (simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether (1:1, v/v) as an extract solvent and analyzed by GC-FID and GC/MS. Identification of the volatile flavor components in aroma concentrate was mostly based on the RI of GC and mass spectrum of GC/MS. Twenty five hydrocarbons, 15 alcohols, 3 aldehydes, 6 esters, 2 ketones and 1 acid were identified in the whole edible portion of angelica. Twenty hydrocarbons, 13 alcohols, 4 esters and 1 acid were identified in the stem sample of angelica. Nineteen hydrocarbons, 11 alcohols, 4 aldehydes, 6 esters, 2 ketones and 1 acid were identified in the leaf sample of angelica. ${\gamma}-Terpinene$, germacrene B, ${\delta}-3-carene$, cis-3-hexen-1-ol, ${\gamma}-muurolene$ and ${\gamma}-elemene$ were the main components in each edible portions of angelica. The terpenoid compounds in volatile flavor components identified from whole edible portion, stem and leaf samples were confirmed as 75.76%, 86.42% and 78.21%, respectively. These results suggest that terpenoid compounds have a great effect on the flavor characteristics of angelica.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.380-386
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• 1995

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components with Commelina communis L.. Essential oils from the samples were isolated by simultaneous steam distillation-extraction(SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography(GC) and combined gas chromatography-mass spectrometry(GC-MS). Respective 29, 47, 36, and 24 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components were evidently depended upon the drying methods. 6,10,14-trimethylpentadecanone was regarded as the most abundant component in shady air dried samples, 6,10,14-trimethyl-2-pentadecanone in presteamed and shady air dried samples, neophytadiene in microwave dried samples, and ethyl acetate in freeze dried samples.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.291-295
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• 2018

Metcalfa pruinosa is a pest causing widespread problems to many crops in Korea. This pest infects fruit crops especially, persimmon and grapes. We tested the possibility of M. pruinosa management using essential oils of Alpina galangal and methylcinnamate which were extracted from A. galangal by steam distillation method. The use of essential oil showed a mortality rate of 10.0 and 23.3% for adults and nymphs, respectively. While the use of methylcinnamate resulted to a mortality rate of 40.0% in adults and 36.6% in nymphs. For its repellent effect, it showed an avoidance rate of 50.0 and 63.3% for adult and nymph respectively. Considering these two results, the extract of A. galangal are shown to have some synergic effect for pest control. The result of this study showed a possibility of M. pruinosa control using essential oil and methylcinnamate from A. galangal.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.134-142
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• 1997

Pectin and tannin analysis were carried out to inverstigate any available components from Pinus densiflora, P. koraiensis, P. thunbergii and P. rigida. To analyze terpenoid components, the essential oils were extracted with steam distillation method from four kinds of pine needles. The essential oil was analyzed by GC and GC-MS spectroscopy. The results were summarized as follows: Pectin content was highest in P. koraiensis with 0.40%, and tannin content was highest in P. koraiensis with 1.05. Major components of P. densiflora needles were ${\alpha}$-pinene, ${\beta}$-caryophyllene, ${\Delta}^3$-carene and phytol. ${\alpha}$-Pinene, ${\Delta}^3$-carene, ${\beta}$-caryophyllene, germacrene D, and camphene were found major components in P. koraiensis. Major components of P. thunbergii needles were ${\beta}$-pinene, ${\alpha}$-pinene, ${\beta}$-caryophyllene and germacrene D. ${\beta}$-Pinene, ${\alpha}$-piene, humulene oxide and ${\alpha}$-elemene were major components in P. rigida. Sabinene and citronellol were infrequent components in P. koraiensis, and ${\alpha}$-pinene oxide was present only in P. rigida. ${\alpha}$-Pinene, limonene, and bornylacetate well known as the main components of green air bath were found in P. densiflora and P. koraiensis.

• Journal of the Korean Ceramic Society
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• v.43 no.12 s.295
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• pp.812-822
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• 2006

This study amis to investigate the functional analysis of anode and cathode materials in Anode supported Solid Oxide Fuel Cell. The concentration polarization of single cell was investigated with CFD (Computational Fluid Dynamics) method for the case of the different morphology by using four types of unit cell and discussed to reduce the concentration polarization. The concentration polarization at anode side effected the voltage loss in Anode supported Solid Oxide Fuel Cell and increased contact areas between fuel gas and anode side could reduce the concentration polarization. For intermediate temperature operation, Anode-supported single cells with thin electrolyte layer of YSZ (Yttria-Stabilized Zirconia) were fabricated and short stacks were built and evaluated. We also developed diesel and methane autothermal reforming (ATR) reactors in order to provide fuels to SOFC stacks. Influences of the $H_2O/C$ (steam to carbon ratio), $O_2/C$ (oxygen to carbon ratio) and GHSV (Gas Hourly Space Velocity) on performances of stacks have been investigated. Performance of the stack operated with a diesel reformer was lower than with using hydrogen as a fuel due to lower Nernst voltage and carbon formation at anode side. The stack operated with a natural gas reformer showed similar performances as with using hydrogen. Effects of various reformer parameters such as $H_2O/C$ and $O_2/C$ were carefully investigated. It is found that $O_2/C$ is a sensitive parameter to control stack performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.27-34
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• 1987

The present paper was attempted to obtain the basic date concerning a reasonable preparing method and optimum fermentation conditions of Kochujang (Red pepper paste). To establish the standard quality of Kochujang, the chemical compositions and the volatile components of Kochujang was discussed. The native Kochujang collected from 80 households contained 40.51% of moisture, 6.00% of salts, 3.25 % of crude fat, 10.30 % of crude ash, pH 4.79, 9.28ml of tillable acidity. 19.60% of reducing sugar, 179.51 mg/100g of amino nitrogen and 4.43% of total nitrogen. The volatiles of Kochujang were extracted by a steam-distillation under the reduced pressure and determined by gas chromatography-mass spectrometry (GC-MS). Total volatile components identified in the native Kochujang were 46 components, i. e., 30 components in neutral fraction, 8 components in phenolic fraction and 8 components in acidic fraction, respectively. But no components were detected basic fraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.195-202
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• 2008

This study was performed to examine the effects of electron beam irradiation on volatile flavor components of Shingo pear (Pyrus pyrifolia cv. Niitaka) and on their changes according to storing period following irradiation. Volatile flavor components in pear were extracted using simultaneous steam distillation and extraction (SDE) apparatus and analyzed by GC/MS. 46 components were identified in control whereas 45, 44, 48 and 51 components were identified in irradiated samples by electron beam at 0.25, 0.5, 1, and 3 kGy, respectively. Hexanal, n-hexanol, and (E)-2-hexenal were identified as the major volatile flavor components of all samples. The characteristic volatile flavor components of irradiated pear by electron beam were similar to those of control, and their effects depending on irradiation source were not different. In addition, there was no noticeable change in volatile flavor components of pear with storage at $4^{\circ}C$ for 30 days or with irradiation. Sensory evaluation indicated that the consumer receptiveness tended to be higher at a low level of radiation dose under 1 kGy than control, albeit not significant. Therefore, electron beam irradiation at low level of radiation dose under 1 kGy could be considered as an effective method to exterminate vermin and thus to improve the shelf-stability of pear without deterioration.

• Food Science and Preservation
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• v.13 no.1
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• pp.108-114
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• 2006

This study was conducted to determine the volatile flavor compositions of the essential oil and the headspace of Capsella bursa-pastoris Medicus. Essential oil and headspace from the plant were extracted by simultaneous steam distillation extraction (SDE), and solid-phase microextraction(SPME) methods, respectively. Seventy-two compounds including 28 hydrocarbons, 4 aldehydes, 6 ketones, 16 alcohols, 4 esters, 8 acids, and 6 miscellaneous ones were identified in the leaf essential oil extracted by SDE method Sixty-eight compounds including 26 hydrocarbons, 2 aldehydes, 6 ketones, 17 alcohols, 4 esters, 6 acids, and 7 miscellaneous ones were identified in the root essential oil. According to the instrumental analyses the essential oil, phytol ($21.12\%$ in leaves, $20.94\%$ in roots) was the most abundant compound Alcohols, esters, and acids were main groups of the essential oil. On the other hand, thirty-eight compounds including 18 hydrocarbons, 3 aldehydes, 3 ketones, 9 alcohols, 2 esters, 3 miscellaneous ones were identified in the leaf headspace by SPME. In root headspace, thirty-three compounds including 16 hydrocarbons, 2 aldehydes, 1 ketone, 9 alcohols, 3 esten;, and 2 miscellaneous ones were identified. Hydrocarbons($44.02\%$ in leaves, $56.98\%$ in roots) were the main components of the headspace of Capsella bursa-pastoris Medicus.

• Food Science and Preservation
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• v.14 no.3
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• pp.308-314
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• 2007

To investigate effects of fermentation on volatile components, we analyzed volatile organic compounds of raw and fermented Rhus verniciflua S. bark. A 50%(w/v) sugar solution was used for fermentation. Volatile organic compounds of raw and fermented Rhus verniciflua S. were extracted by the simultaneous steam distillation and extraction(SDE) method, with a mixture of n-pentane and diethylether(1:1, v/v) and analyzed by gas chromatograph-mass spectrometer. A total of 51 and 27 volatile organic compounds were detected in raw and fermented samples, respectively, and were mainly alcohols. Compounds such as ethyl acetate, 2-methyl-3-buten-2-ol, 3-methylbutanal, 1-octen-3-o1, 3-methyl-2-butanone, hexanal and pentanal were detected as the primary compounds in the raw sample. The fermented sample showed sour different volatile compounds, such as ethanol, ethyl acetate, ethyl lactate and 3-methylbutanol. Thus, a number of volatile organic compounds were synthesized after fermentation of Rhus verniciflua S. bark.