• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1351-1355
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• 1998

A simple apparatus for adding a modifying solvent to supercritical CO2 extractant was described. Small, fixed volumes (typically 100 μL) of liquid modifying solvents were delivered during the extraction process by use of an in-line high pressure loop injector and an air pump. Without disconnecting the extraction cell from the supercritical fluid extraction system, the modifying solvent was repeatedly delivered. The solvent modification device was optimized during the extraction of carbaryl and bis(acetylacetonato) copper(Ⅱ). Extraction recoveries from spiked filter paper and soil samples ranged between 22% and 109%, depending on the analyte and matrix components. The addition of polar modifying solvents were necessary to improve the extractability of the nonpolar CO2.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.202-206
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• 1997

To develop mil fat fractions with desirable physico-chemical properties, anhydrous milk fat (AMF) was fractionated by one- and two-stage extractions using supercritical $CO_2$(SC-$CO_2$). Tow-stage extraction of AMF was performed by first producing tow fractions, an extract and a residue at 4$0^{\circ}C$/241bar, which were subsequently used as the feed for an extraction at 6$0^{\circ}C$/241bar and 4$0^{\circ}C$/345bar, and separated into five and four fractions, respectively, based one extraction time. These fractions were quantified and analyzed for fatty acids and physico-chemical properties. SHort-chain (C4~C8) fatty acids in extract fractions from an extract were 200~150% compared with those of the original AF. Long-chain (C14~C18) fatty acids in extract fractions from a residue were 118~141%. The ratio of unsaturated fatty acids in the residue fraction was 131%. Melting point ranged from 22 to 43$^{\circ}C$, iodine value 21.8 to 36.9, and saponification value 255 to 221 in the extract and residue fractions. SC-$CO_2$ fractionation of AMF by two-stage extraction offers the possibility of developing ractions with discrete fatty acid compositions and physico-chemical properties such as melting point, iodine value and saponification value.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.470-474
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• 2008

The whole berry, pulp, and seed of sea buckthorn fruit were extracted with supercritical $CO_2$ to produce edible oils. The effects of extraction pressure, temperature, and $CO_2$ flow rate on the oil yield and extraction rate were investigated, and the fatty acid composition, tocopherol, and carotenoid contents of the oils were compared. The results showed that the extraction rate was affected by pressure, temperature, and $CO_2$ flow rate and, in general, the yield increased with a rise in any of the 3 variables. Fatty acids in the whole berry and pulp oil were dominated by monounsaturated fatty acids (>64%), followed by saturated fatty acids (about 30%). In contrast, fatty acids in the seed oil consisted mainly of polyunsaturated (>60%) and monounsaturated fatty acids (>24%). The seed oil had a slightly higher content of tocopherols, but a much lower content of carotenoids, compared with the whole berry or pulp oil.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.405-406
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• 2007

In this paper, we propose feature extraction and tracking algorithm using multi resolution in 2-dimensional wavelet domain. Feature extraction selects feature points using 2-level wavelet transform in interested region. Feature tracking estimates displacement between current frame and next frame based on feature point which is selected feature extraction algorithm. Experimental results show that the proposed algorithm confirmed a better performance than the existing other algorithms.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1057-1061
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• 2002

Effects of modifier and soaking on extraction of triterpenoid saponin (glycyrrhizin) from liquorice were examined using supercritical $CO_2(SC-CO_2)$ at 50 MPa, $60^{\circ}C$, and flow rate of 3 mL/min, and glycyrrhizin content was analyzed by HPLC. Additon of undiluted methanol, ethanol or isopropanol as modifier to $SC-CO_2$ had little influence on extraction yield of glycyrrhizin. Soaking process using water increased the extraction yield as the sample to solvent ratio was increased. Addition of 70% methanol, ethanol or isopropanol to $SC-CO_2$ significantly increased the extraction yields, with 70% methanol resulting in the highest yield. When water at 90% (w/w) of sample weight was used for soaking, the extraction yield and rate increased, 70% ethanol-modified $SC-CO_2$ was almost equal to that obtained using 70% methanol.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.319-326
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• 2009

This study was carried out to investigate the high-acidity co-separation of Am and RE from a simulated radwaste solution by a solvent extraction using a mixture of Dimethyldibutyltetradecylmalonamide (DMDBTDMA, as an extractant) and dihexyl octanamide (DHOA, as a phase modifier) diluted with n-dodecane (NDD). All the experiments were conducted as a batch type. First, the environmentally friendly DMDBTDMA and DHOA composed of only CHON atoms were self-synthesized. Then, the conditions for the prevention of a third phase, generated in the organic phase were examined. In addition, the effects of the concentration of nitric acid, DHOA, oxalic acid and $H_2O_2$ on the co-extraction of Am and RE were elucidated. Consequently, the optimum condition of (0.5M DMDBTDMA+0.5M DHOA)/NDD-0.3M $C_2H_2O_4-4.5M$ $HNO_3$ and O/A=2 was obtained through experimental work. Under this condition, the extraction yields were found to be about 80% for Am, more than 70% for RE such as La, Eu, Nd, Ce, etc., 3% for Cs and Sr, 69% for Fe and less than 11% for Mo and Ru. For the co-extraction of Am and RE, Fe should be removed in advance or prevented from a co-extraction with Am by controlling the different extraction rates of Am and Fe. About 95% of the Am and RE in the organic phase were stripped using a 0.5M $HNO_3$.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.414-419
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• 1995

${\beta}-carotene$ was extracted from freeze-dried carrot by supercritical carbon dioxide $(SC-CO_2)$ and mixtures of $CO_2$ doped with ethanol or methanol as a cosolvent at temperatures of 40 to $60^{\circ}C$ and pressures of 138 to 276 bar. Solubility of ${\beta}-carotene$ in $SC-CO_2$ increased with the increase of extraction pressure and the decrease of extraction temperature. The highest solubility observed was $4.90\;{\mu}g/g\;CO_2\;for\;{\alpha}-carotene\;and\;0.604\;{\mu}g/g\;CO_2$ for ${\alpha}-carotene\;at\;40^{\circ}C$ and 276 bar. Addition of ethanol increased the solubility being the largest increase of 82% using a mixture of $CO_2$ and 17.4% ethanol. $SC-CO_2$ extraction can be used to selectively obtain natural carotenoids, free of solvent residuals, which can be used as food additives.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1439-1443
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• 2006

This study was performed on the effects of extraction temperature, pressure, time on apparent solubility and extraction yield of perilla oil and tocopherol, and color and fatty acid composition of the residue in supercritical carbon dioxide $(SC-CO_2)$ extraction. Apparent solubility of perilla oil and tocopherol increased with the increase of $CO_2$ density and was found to strongly depend on extraction pressure rather than extraction temperature. The extract yield of tocopherol in $SC-CO_2$ extraction increased with an increase of temperature and decreased with an increase of pressure and extraction time. The perilla oil apparent solubility of dried perilla powder for $60\sim180$ min at $40^{\circ}C/276$ bar increased with an extraction time, on the other hands, tocopherol apparent solubility decreased. As the increase of $CO_2$ density, less redness and yellowness increased. Fatty acid composition of perilla oil showed that perilla oil extracted by $SC-CO_2$ had better unsaturated fatty acid and decreased in saturated fatty acid. $SC-CO_2$ extraction offers a safe natural method for gaining perilla oil from dried perilla seeds powder.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.306-311
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• 2000

Lipid and cholesterol were extracted from beef and pork by the supercritical carbon dioxide $(SC-CO_2)$ for the manufacturing of low-lipid and low-cholesterol sausage. The ranges of extraction temperature and pressure were from 35 to $55^{\circ}C$ and from 103 to 375 bar, respectively. $SC-CO_2$ extraction yield of beef lipid increased as extraction pressure increased and/or extraction temperature decreased, while extraction temperature was more influential on the cholesterol extraction than pressure condition. When lipid and cholesterol of freeze-dried beef with varied moisture contents were extracted, their solubilities increased as the moisture content reduced. The extraction of lipid and cholesterol from pork was shown the same tendency as the beef. The chunk type of beef shape was more suitable for the lipid and cholesterol extraction than the powder type of beef. The color of meat after $SC-CO_2$ extraction was lighter than the raw freeze dried meat because of the extraction of color pigments. After $SC-CO_2$ extraction, beef and pork were rehydrated and mixed with raw beef and pork containing lipid and cholesterol. Their mixing ratio up to 50 : 50 did not affect physical properties of the sausage compared with the control sausage.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.609-613
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• 2005

Daidzein and genistein were extracted from Korean soybean by supercritical $CO_2$ and sub/supercritical water. The extracted sample was analyzed by reversed-phase high performance liquid chromatography (RP-HPLC). The retention time, retention factor, column efficiency, column selectivity and resolution of aglycons were compared with the change in the temperature and pressure of supercritical fluid and ethanol concentration. The characteristics of extraction of daidzein and genistein were more affected by ethanol concentration using supercritical $CO_2$. The most desirable extraction yield was obtained by supercritical $H_2O$ with $400^{\circ}C$ and 250 bar. Generally, the extraction yield of aglycons increased over 10 times using supercritical $CO_2$ than sub/supercritical $H_2O$.