• Food Science and Preservation
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• v.17 no.2
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• pp.281-289
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• 2010

We determined the optimum ethanolic conditions for extraction of $\gamma$-oryzanol and other functional components from rice bran, using response surface methodology (RSM). A central composite design was used to investigate the effects of the independent variables of solvent ratio ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables including yield ($Y_1$), total phenolic content ($Y_2$), electron-donating activity ($Y_3$), ferulic acid level ($Y_4$), and $\gamma$-oryzanol concentration ($Y_5$). Solvent ratio and extraction temperature were the most important factors in extraction. The maximum yield was at 22.56 mL/g ($X_1$), 78.19C ($X_2$), and 522.15 min ($X_3$), at the saddle point. Total phenolic levels were little affected by solvent ratio or extraction temperature. The maximum concentration of extracted total phenolics was 90.78mg GAE/100 g at 21.26 mL/g, $94.65^{\circ}C$, and 567.97 min. A maximum electron-donating ability of 54.72% was obtained with the parameters 20.20 mL/g,$81.89^{\circ}C$, and 701.87 min, at the highest point. The maximum level of ferulic acid components was 210.47 mg/100g at 5.22 mL/g, $79.66^{\circ}C$, and 575.24 min. In addition, the maximum $\gamma$-oryzanol concentration was 660.39 mg/100g at 5.10 mL/g, $81.83^{\circ}C$, and 587.39 min. The optimum extraction conditions were a solvent ratio of 10.45 mL/g, $80^{\circ}C$ extraction temperature, and 535 min extraction time. Predicted extraction levels under optimized conditions were in line with experimental values.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.43-52
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• 1998

The objective of this study is to investigate the optimum conditions of extracting collagen without chrome ion from the leather waste. The effect of temperature, pH, and the concentration of alkaline solution on the collagen extraction has been studied. The result indicated that the incipient denatured temperature of collagen measured by viscosity was $25^{\circ}C$ and the complete denatured temperature was $31.5^{\circ}C$. The optimum solubilization condition for temperature was between $15^{\circ}C$ and $20^{\circ}C$, pH was 1.5, the concentration of alkaline solution was 3% of sodium hydroxide. The almost complete chrome ion separation was possible around the pH of 1.5. The separation efficiency of chrome ion from tannery waste was more than 99.5%. Extraction efficiency of crude protein from leather waste was about 89.5%. The hydroxyproline and collagen content in the extracted crude protein were 8.53% and 63.62%, respectively.

• Korean Journal of Optics and Photonics
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• v.32 no.6
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• pp.306-313
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• 2021

We study the amplification properties of an optical amplifier based on a cesium-vapor cell. An optical amplification system including cesium vapor mixed with a buffer gas is built, and its amplification feature is investigated as a function of the size of the incident beam and the temperature of the cesium-vapor cell. We observe that the optical amplification properties, such as amplification factor and extraction efficiency, change significantly depending on the temperature and beam diameter of the pump and seed light. A maximum extraction efficiency of 56% is obtained when the temperature of the cesium cell is 90 ℃, with a 200-㎛ diameter of the pump (500 mW) and seed light (10 mW). The numerical simulation of the amplification properties agrees reasonably with the results obtained from the experiment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.7
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• pp.549-556
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• 2001

Heat flow characteristics during hot water extraction process was studied experimentally. Data were taken at various outlet port type for the fixed inlet port type, inlet-outlet temperature differences and mass flow rates. In this study, the temperature distribution in a storage tank and an outlet temperature were measured to predict a flow pattern in the storage tank, and a hot water extraction efficiency was analysed with respect to the variables dominating a extraction process. Experimental results show that the extraction efficiency is high in a low flow rate in case of using modified distributor I(MDI) as a outlet port type.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.327-331
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• 1996

This experiment was conducted to establish the efficient extraction condition for anthocyanin and tannin pigments contained in rice bran of colored rices. Efficiency of the pigment extraction was maximum when the concentration of mired solvent of methanol(3) : ethanol(7) was 70%. In purple rite(anthocyanin pigment), ‘Kilimheugmi’, 80% ethanol containing 0.5% malic acid showed the highest extraction efficiency and stability with a maximum absorbance wavelength$(\lambda_{max})$ at 538 nm. In red rice(tannin pigment), ‘Jagwangdo’, 80% ethanol containing 0.01% citric acid showed the highest extraction efficiency and stability with a maximum absorbance wavelength$(\lambda_{max})$ at 456 nm. The relative optical density of the pigments increased until the solvent temperature was reached at $70^{\circ}C$, but drastically decreased over at $90^{\circ}C$ due to color change. The higher amount of the pigment was ertracted from the longer shaking time of the solvent. Ten minutes was enough for the grinding time of rite bran in solvent. Supernatant of the pigment extractives after one day storage at $4^{\circ}C$ in dark chamber revealed higher optical density than the filtration of the pigment extractives.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.97-103
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• 2015

This study investigated changes in phenolic contents of different parts of Rhus verniciflua Stokes (RV) according to extraction conditions. Bark and xylem parts of RV were extracted at 80, 100, 120, 140, and $160^{\circ}C$ for 1, 3, and 5 h, respectively. Major phenolic compounds (gallic acid, protocatechuic acid, fustin, fisetin, sulfuretin, and butein) of RV were analyzed. The gallic acid, fisetin, sulfuretin, and butein contents significantly increased as extraction temperature increased. Protocatechuic acid and fustin contents increased as increasing extraction temperature to $120^{\circ}C$ and decreased afterward. The gallic acid, protocatechuic acid, and butein contents of bark were higher than those of xylem extracts. The optimal extraction conditions of gallic acid, protocatechuic acid, fustin, fisetin, sulfuretin, and butein were $160^{\circ}C/3h$ (380.22 mg%), $120^{\circ}C/1h$ (9.25 mg%), $100^{\circ}C/3h$ (206.97 mg%), $140^{\circ}C/5h$ (93.84 mg%), $140^{\circ}C/5h$ (16.07 mg%) and $160^{\circ}C/5h$ (1.49 mg%), respectively. These results suggest that the optimum extraction temperature and time considering RV extraction yield and cost are $140^{\circ}C$ and 3 h, respectively.

• Food Science and Preservation
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• v.12 no.4
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• pp.367-371
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• 2005

This study analyzed the extraction condition for large-scale extraction process to be used industrially. The total sugar content of 5-year Red ginseng in viewpoint of the ginseng materials was highest by $32\%$ and it of 5-year Keumsan ginseng was $31\%$. Therefore 5-year Keumsan ginseng was used by test sample. The next extraction condition, that is the total sugar content of the internal white among the parts of ginseng, the extraction efficiency under the condition of optimal temperature $80^{\circ}C$ and optimal extract time 6hrs, was highest. And the amount of total sugar extracted from ginseng treated with protease, ${\alpha}-amylase$ and cellulase was increased about $20\%$. Total sugar recovery in methods of alcohol concentration $70\%$ and freezer-dry method was highest.

• Journal of Nutrition and Health
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• v.54 no.1
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• pp.116-128
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• 2021

Purpose: The extraction conditions for bioactive components from peanut shells, which is a byproduct of peanut processing, were optimized to enhance the total phenolic content (TPC, Y1), total flavonoid content (TFC, Y2), and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (RSA, Y3). In addition, this study evaluated the anti-obesity effect of peanut shell extract. Methods: Optimization of ultrasonic-assisted extraction (UAE) was performed using a response surface methodology. The independent variables applied for extraction were time (X1: 5.0-55.0), temperature (X2: 26.0-94.0), and ethanol concentration (X3: 0.0%-99.5%). Quadratic regression models were derived based on the results of 17 experimental sets, and an analysis of the variance was performed to verify its accuracy and precision of the regression equations. Results: When evaluating the effects of independent variables on responses using statistically-based optimization, the independent variable with the most significant effect on the TPC, TFC, and RSA was the ethanol concentration (p = 0.0008). The optimal extraction conditions to satisfy all three responses were 35.8 minutes, 82.7℃, and 96.0% ethanol. Under these conditions, the inhibitory activities of α-glucosidase and pancreatic lipase by the extract were 86.4% and 78.5%, respectively. Conclusion: In this study, UAE showed superior extraction efficiency compared to conventional hot-water extraction in the extraction of polyphenols and bioactive materials. In addition, α-glucosidase and pancreatic lipase inhibitory effects were identified, suggesting that peanut shells can be used as effective antioxidants and anti-obesity agents in functional foods and medicines.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.83-89
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• 2011

Various functional and useful components in Portulaca oleracea were extracted with ethanol and the optimum solvent conditions were set by monitoring of response surface methodology(RSM). A central composite design for optimization was applied to investigate the effects of the three independent variables of extraction temperature, ethanol concentration, and extraction time, on dependent variables including total phenolics, electron-donating ability, brown clolor and total flavonoids of Portulaca oleracea. The content of total phenol was essentially unaffected by extraction time or extraction temperature, but it was highly influenced by ethanol concentration. The maximum total phenol content was 31.70mg/mL obtained at 45.84% of ethanol concentration, $79.66^{\circ}C$, and after 2.67hr of extraction. Electron-donating ability (EDA) was affected by ethanol concentration and the maximum EDA was 74.67mg/mL at 52.95% ethanol concentration, $52.33^{\circ}C$ and 4.84hr of extration time. The browning color was rarely affected by extraction time but, it was highly influenced by ethanol concentration and extraction temperature. The maximum extent of browning color was obtained at 97.75% of ethanol concentraion, $65.88^{\circ}C$ and 2.93hr of extraction time. The content of total flavonoid was significantly influenced by extraction time, and the maximum total flavonoid level was 58.28mg/mL obtained at 96.62% ethanol concentration, $61.87^{\circ}C$ after 3.70hr of extraction. As a result, The optimal conditions for effective extraction were predicted as follows, 70.3% of ethanol concentration, $62.1^{\circ}C$ of extraction temperature and 3.3hr of extraction time.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.288-294
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• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.