• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1104-1109
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• 2003

Response surface methodology (RSM) was used to investigate the effects of the processing parameters on supercritical $CO_2\;(SC-CO_2)$. extraction of total carotenoids and ${\beta}$-cyptoxanthin from Citrus unshiu press cake. The parameters tested were $SC-CO_2$ pressure, dynamic extraction time, and concentration of ethanol added as the modifier to $CO_2$. Experimental data correlated well with the processing parameters (p<0.01), and there was a high statistically significant multiple regression relationship for the extraction of total carotenoids and ${\beta}-cyrptoxanthin$ ($R^2=0.9789$ and 0.9796, respectively). The optimal processing conditions were extraction pressure 33.4 and 37.3 MPa, extraction time 39.6 and 41.0 min, ethanol concentration 18.6 and 17.0% for total carotenoids and ${\beta}-cryptozanthin$, respectively. Maximum extraction yields predicted by RSM were 61.1 and 95.8% ppm, respectively. The extraction yield of total carotenoids increased asymptotically with the increase of the extraction pressure. It increased in proportion to extraction time and concentration of the cosolvent. The extraction yield of ${\beta}-cryptoxanthin$ increased with extraction pressure, extraction time, and concentration of the cosolvent. The extraction time and the concentration of the cosolvent, and the interaction between extraction time and the concentration of the cosolvent significantly affected the extraction yields of carotenoids from C. unshiu press cake.

• Journal of Pharmaceutical Investigation
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• v.8 no.2
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• pp.1-10
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• 1978

During the course of studies on the production of glutathione from yeast, process development and optimization was carried out. The optimal pH for the extraction of glutathione was found to be 2.5 to 4.0 and the maximum yield for glutathione was obtained when the extraction temperature was 25 to $45^{\circ}C$. The cuprous salt of glutathione was recovered maximally at the range of 2 to 4g of cuprous oxide per 10 Kg of compressed yeast. Further purification was needed for the removal of impurities from glutathione. Cation exchange resin, anion exchange resin and Sephadex G-25 were employed for this purpose. 13 to 15 g of glutathione was obtained from 10 Kg of compressed yeast and the purity was above 99.3%.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.117-124
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• 2015

The extract of white rose petals has an antioxidant effect and can be used to treat allergic disease. The purpose of this study was to identify optimal conditions for extracting antioxidative compounds from white rose petals with 2,2-diphenyl-1-picrylhydrazyl scavenging activities. A response surface methodology based on a central composite design was used to investigate the effects of three independent variables: ethanol concentration ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$). The estimated optimal conditions for obtaining phenolic compounds with antioxidant activities were as follows: ethanol concentration of 42% ($X_1$), extraction time of 80 min ($X_3$), and extraction temperature of $75^{\circ}C$ ($X_2$). The estimated optimal conditions for obtaining flavonoid compounds with antioxidant effects were an ethanol concentration of 41% ($X_1$), extraction time of 119 min ($X_3$), and an extraction temperature of $75^{\circ}C$ ($X_2$). Under these conditions, predicted response values for the phenolic and flavonoid contents were 243.5 mg gallic acid equivalent/g dry mass and 19.93 mg catechin equivalent (CE)/g dry mass, respectively.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1163-1168
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• 1998

Fish tissues were spiked with organophosphorus pesticides (OPPs), mixed with a celite as a drying agent, and dynamically extracted with pure $CO_2$ or modified $CO_2$ for 10 min at different extraction temperatures, pressures and $CO_2$ flow rates. Recoveries of OPPs spiked in jacopever increased with the decrease of extraction temperature and pressure, and decreased with the increase of $CO_2$ flow rates. Modified $CO_2$ extractions with 10% methylene chloride showed a slight increase in the recoveries over pure $CO_2$ extraction. Quantity of fish tissues had great effect on their extraction efficiencies. Recoveries of OPPs were $66.7{\sim}86.3%$ for jacopever, $56.2{\sim}79.2%$ for yellow tail, $57.6{\sim}77.8%$ for blanquillo, $84.2{\sim}96.3%$ for sardine, $74.6{\sim}83.6%$ for mackerel. Application of supercritical carbon dioxide extraction offers an attractive alternative to the use of organic solvents for extraction of pesticide residues from fish tissues.

• KSBB Journal
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• v.15 no.1
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• pp.80-83
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• 2000

Polyacetylenes were extracted from Korean ginseng using supercritical $CO_2$ Yield of extraction of panaxydol and panaxynol was increased as the pressure of supercritical $CO_2$ increased at the range from 200 to 300 bar. The optimal yields of panaxydol and panaxynol was achieved at 65 and $55^{\circ}C$, respectively. Methanol was applied as a modifier. The highest yield of panaxydol and panaxynol were 0.230 and 0.054 mg/g-dry weight at modifier concentration of 10%(w/w), 300 bar, and $65^{\circ}C$. When these results were compared to that of methanol-extraction, the recoveries of panaxydol and panaxynol by supercritical $CO_2$ extraction in SFE were 37.8 and 55.1%, respectively.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.205-217
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• 2017

Mineral carbonation by indirect method has been studied by serpentinite as cation source. Through the carbonation of $CO_2$ and alkaline earth ions (calcium and magnesium) from serpentinite, the pure carbonates including $MgCO_3$ and $CaCO_3$ were synthesized. The extraction solvent used to extract magnesium (Mg) was ammonium sulfate ($(NH_4)_2SO_4$), and the investigated experimental factors were the concentration of $(NH_4)_2SO_4$, reaction temperature, and ratio of serpentinite to the extraction solvent. From this study, the Mg extraction efficiency of approximately 80 wt% was obtained under the conditions of 2 M $(NH_4)_2SO_4$, $300^{\circ}C$, and a ratio of 5 g of serpentinite/75 mL of extraction solvent. The Mg extraction efficiency was proportional to the concentration and reaction temperature. $NH_3$ produced from the Mg extraction of serpentinite was used as a pH swing agent for carbonation to increase the pH value. About 1.78 M of $NH_3$ as the form of $NH_4{^+}$ was recovered after Mg extraction from serpentinite. And, the main step in Mg extraction process of serpentinite was estimated by geochemical modeling.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1218-1223
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• 2021

A hydrophobic ionic liquid including an amino moiety ([DiOcAPmim][NTf₂]) was synthesized. Its extraction behaviors towards Pd(II), Ru(III), Rh(III) were investigated in nitric acid aqueous solution as a function of contact time, effect of concentration of nitric acid, effect of temperature, and effect of co-existing metal ions. The extraction kinetics of Pd(II) was fairly fast and extraction equilibrium can be attained within only 5 min under the [HNO₃] = 2.05 M. When [HNO₃]< 1 M, the extraction percentage of Pd(II), Ru(III), Rh(III) were all above 80%. When [HNO₃] reached 2 M, all of the extraction percentage decreased and in an order of Pd(II)>Ru(III)>Rh(III). When [HNO₃]> 2 M, the extraction performance gradually recovered. The effect of temperature can slightly affect the extraction performance of Pd(II). Furthermore, in simulated high-level liquid waste, [DiOcAPmim][NTf₂] showed a better preference towards Pd(II) under the interference of various other co-existing metal ions.

• Food Engineering Progress
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• v.23 no.1
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• pp.22-29
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• 2019

This study was carried out using Celluclast 1.5L to increase the content of 2,6-DMBQ and water extractable arabinoxylan in wheat germ extract. Extraction temperatures were 30℃, 45℃ and 60℃. The extraction times were 0, 6, 12, 18, 24 and 30 h. The pH of the extract decreased rapidly from 18 h at 30℃ in both water- and enzyme-treated extracts. 2,6-DMBQ of water- and enzyme-treated extracts increased with the extraction time. At 30-hour extraction time, enzyme-treated extract increased 27.60% at 30℃ extraction temperature than water extraction. Extraction temperatures of 45℃ and 60℃ were increased by 65.03% and 151.05%, respectively. The highest content of water-extractable arabinoxylan was 15.23±0.08 mg/g when the enzyme was treated at an extraction temperature of 60℃ for 30 h. At 30=hour extraction time, enzyme-treated extract increased 7.92% at 30℃ extraction temperature compared to water extraction. Extraction temperatures of 45℃ and 60℃ were increased by 31.20% and 54.38%, respectively.

• Analytical Science and Technology
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• v.21 no.5
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• pp.392-396
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• 2008

Acer tegmentosum is a tree used to treat various liver diseases in Korea. There have been some concern regarding the safety of Acer tegmentosum due to some toxic chemical compounds in its stems. Supercritical fluid extraction (SFE) was employed to develop a removing method of toxic compounds from Acer tegmentosum. The toxic compounds were effectively extracted with ethanol modified supercritical fluid $CO_2$. The optimum condition of SFE was 100 bar of pressure, $40^{\circ}C$ of extraction temperature, 3 mL/min of $CO_2$ flow rate, 0.2 mL/min of modifier (ethanol) flow rate.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.578-584
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• 2003

Polychlorinated biphenyls (PCBs) known as environmental contaminants in soil were analyzed by the soil pollution standard process test and the static supercritical $CO_2$ extraction mode. It was shown that the percent average recoveries of PCBs by the soil pollution standard process test were ranged in 25-35% and the corresponding standard deviations were above 10%. In contrast, the percent average recoveries of PCBs by the static supercritical $CO_2$ extraction mode were 2-2.5 times higher and standard deviations were within 7%. These results indicate that static supercritical $CO_2$ extraction mode may be a useful alternative to sample pretreatment certified by the soil pollution standard process test. The increasing supercritical $CO_2$ pressure from 1130 psi to 1996 psi at $40^{\circ}C$ enhanced the recovery of all PCB congeners from soil. However, at same Tc and Pc, the equilibrium time (5 versus 60 minutes) had no effect on the recovery of each PCB congener. Finally, similar PCB recoveries were obtained under the same extraction condition, regardless of the molecular weight and structure (coplanar versus non-coplanar) of PCB congeners.