• Journal of Plant Biology
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• v.19 no.4
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• pp.95-99
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• 1976

This work deals with different extraction media and reaction mixtures on photosystem II activity of Spinach chloroplasts. The photoreduction rate of ferricyanide and DPIP by intact chloroplasts which extracted with four kinds of extraction media; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, was measured in five kinds of reaction mixtures; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, 0.05 M-Tris pH 7.2. The extraction medium which shows the highest photoreduction rate was S-Tris-N at pH 7.2 and S-Tricine-N at pH 8.0. As to the reaciton mixture, S-Tricine-N pH 8.0 showed the highest rate. On the complex effects of extraction media and reaction mixtures, the highest photordeuction rate of Hill oxidant by intact chloroplasts was obtained by S-Tris-N pH 7.2 extraction medium and S-Tricine-N pH 8.0 reaction mixture. The second highest activity was obtained by S-Tricine-N pH 8.0 extraction medium and reaction mixture.

• Food Science and Preservation
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• v.22 no.2
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• pp.256-260
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• 2015

This study investigated the optimum pH condition for the efficient extraction of protein from Gastrodia elata Blume. Five extraction pH values (8, 9, 10, 11, and 12) and three precipitation pH values (2, 4, and 6) were used. The protein content, browning degree, and recovery yield of the protein obtained under each pH condition were determined. Most of the G. elata Blume was made up of carbohydrates, and its protein content was also high. The amount of the extracted protein increased according to the increase in the extraction pH, but did not significantly differ between pH 8 and pH 9. The browning degree of the protein significantly increased as the extraction pH increased. The greatest amount of protein was precipitated at pH 4, the recovery yield of which was also the highest. As a result, it was found that the combination of extraction pH 9 and precipitation pH 4, which resulted in a 38.7% recovery yield and a low browning degree, is the optimum condition for the efficient extraction of protein from G. elata Blume.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.619-624
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• 1995

Sesame protein concentrate(SPC) was prepared from defatted sesame flour(DSF) at several different pH(2.0, 7.0, 9.0, 11.0) for protein extraction. Some of their functional properties were determined in order to compare the effects of pH during preparation of concentrates. Compared with DSF, nitrogen solubility was markedly improved in all SPC, and SPC extracted at pH 11.0 showed the highest solubility at all pH leaves examined. Fatabsorption was increased in all SPC prepared, but water absorption was decreased as the extraction pH of protein increased. The emulsifying properteis and foaming properties of SPC were remarkably higher than DSF. As the extraction pH of protein was increased, the emulsion activity was also increased, but emulsion stability was decreased. SPC extracted at pH 7.0 showed the highest foaming capacity on the other hand, the highest foaming stability was shown in SPC extracted at pH 2.0. As the protein extraction pH increased, the viscosity of the protein solution was increased. SPC extracted at pH 11.0 showed highest viscosity at all protein concentrations tested.

• Resources Recycling
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• v.15 no.4 s.72
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• pp.13-18
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• 2006

This study was to investigate the extraction characteristics of extraction resins containing HEH/EHP for Gadolinium solution. The experiments were carried out with the variation of equilibrium pH and initial concentration of Gd. The optimum extraction time was 90 mins on Gd extraction using resin. The extraction ratio(%) was increased by increasing equilibrium pH from pH 1.0 to 2.0. The experimentally measured amounts of Gd on resins at equilibrium agreed well with those predicted using Freundlich's isotherm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1462-1466
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• 2014

In this study, an attempt was made to produce oat protein concentrates from defatted oat groat by alkali extraction. Independent variables formulated by D-optimal design were NaOH concentration (X1, 0.005~0.06 N) for extraction and precipitation pH (X2, pH 4.0~6.0), and the dependent variable was extraction yield (Y1, %). Experimental results were analyzed by response surface methodology to determine optimized extraction conditions. Extraction yield increased both with an increase in NaOH concentration of the extraction solution and when approaching a precipitation pH of 4.9, and NaOH concentrations were a major influencing parameter. Solubility of oat protein concentrates showed a minimum value (i.e., 0.1%) at pH 5 and increased substantially at pH values in the range of ${\leq}$ pH 3 or ${\geq}$ pH 7, reaching a maximum value at pH 11 (i.e., 76%). Regression equation coincided well with the results of the experiment. Optimized extraction conditions to maximize extraction yield were 0.06 N NaOH (X1) for extraction and pH 4.7 (X2) for precipitation.

• Food Engineering Progress
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• v.15 no.2
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• pp.143-147
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• 2011

For efficient extraction of protein from defatted rice bran, the 5 ranges of extraction pH (8, 9, 10, 11 and 12) and the 3 ranges of isoelectric precipitation pH (2, 4 and 6) were used. The protein content, browning reaction, the electrophoresis pattern and the recovery yield of soluble protein at each pH range were compared each other. The recovery yield of soluble protein increased in proportion to extraction pH, but at the same time, browning reaction became more conspicuous. The most amount of protein was recovered at the precipitation pH of 4. The SDS-PAGE patterns of the extracted proteins showed no significant correlations between pH and the protein content, but the highly alkaline condition was more advantageous to extract protein less than 35 kDa. In each pH range, the recovery yield of soluble protein averagely reached 32.5% on the basis of extraction. In result, it was found that combination of extraction pH 10 and precipitation pH 4, which resulted in 37.65% of recovery yield and low level of browning reaction, was the optimum condition for the extraction of protein from defatted rice bran.

• Analytical Science and Technology
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• v.9 no.3
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• pp.221-234
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• 1996

Basic studies for the effective extraction of dibenzylammonium dibenzyldithiocarbamate(DBADBDC) complexes of Ag(I), Pd(II), Au(III) and Pt(IV) into chloroform have been conducted. The effects of pH on the extraction of ligand itself and metal cemplexes showed that DBADBDC itself was uniformly extracted in the pH range of 2~9 and metal complexes were effectively extracted at the pH range as follows. That is, Ag(I) : in an acidic aqua medium, Pd(II) : > 4, Au(III) : wide range, and Pt(IV) : > 3. The distribution ratio and extractabilities were obtained from the partition and extraction equilibria of metal-DBDC complexes between aqueous solution and chloroform. Ag(I) : log D=4.226 : E(%)=99.9% in the aqueous solution of pH 0, Pd(II) : log D=1.804 : E(%)=98.5% at pH 4~7, Au(III) : log D=3.755 : E(%)=99.9% at pH 2~10, and Pt(IV) : log D=0.165 : E(%)=57.2% at pH 8.0. And also mole ratio of metal ion to ligand in complexes were determined by mole ratio method : 1 : 1 for Ag(I) and 1 : 2 for Pd(II), Au(III) and Pt(IV). $Cl^-$ was included as a coordination species in complexes of Au(III) and Pt(IV). Besides, extraction mechanisms of compleses sere examined in the presence of chloride ion in an aquous solution, and extraction reactions and estraction constants could be proposed and calculated, respectively.

• Journal of Environmental Science International
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• v.10 no.5
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• pp.381-386
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• 2001

The characteristics of precipitation separation and solvent extraction separation of magnesium from the waste bittern were studied experimentally In the result of precipitation separation, the size of magnesium hydroxide precipitated was not affected on pH, but decreased with increasing the precipitation temperature. The purity of magnesium oxide precipitated was increased with pH beyond pH 11. From the solvent extraction separation, the equilibrium extraction ratio of magnesium was increased with pH and temperature of extraction phase, the concentration of stripping phase, and with decreasing pH of stripping phase. The extractant of Aliquat 336 and Acid 810 mixture was more effective than that of DCH18C6 and $D_2EHPA$ mixture in the extraction separation of magnesium.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.871-877
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• 2012

This study investigated the effects of temperature, solvent concentration, and pH on the ${\beta}$-glucan extraction. Oat bran ${\beta}$-glucan was extracted with different extraction conditions, using various combinations of experiment factors, such as temperature (40, 45, 50, 55, and $60^{\circ}C$), ethanol concentration (0, 5, 10, 15, and 20%), and pH (5, 6, 7, 8, and 9). Under the various extraction conditions, ${\beta}$-glucan extraction rate and overall mass transfer coefficient of oat bran ${\beta}$-glucan, and viscosity of oat bran extracts were investigated. As increasing the extraction time, the extraction rate of ${\beta}$-glucan increased. The overall mass transfer coefficient of ${\beta}$-glucan ranged from $3.36{\times}10^{-6}$ to $8.55{\times}10^{-6}cm/min$, indicating the lowest at the extraction condition of $45^{\circ}C$, 15% and pH 8, and the highest at $50^{\circ}C$, 0% and pH 7. It was significantly greater with increasing extraction temperature and decreasing ethanol concentrations of extraction solvent, except for solvent pH. There were positive correlations among the overall mass transfer coefficient, the extraction rate of ${\beta}$-glucan, and the viscosity of extract.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.11
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• pp.1350-1357
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• 2003

This research was aimed to establish the standard extraction and analytical procedures for examining the chromophoric substance in madder root with the ultimate goal of identifying the dyes in badly faded textiles of archaeological origin. The separation temperature of gas chromatography, pH and other extraction conditions were tested. The results were as follows: The suitable separation temperature for the GC cappillary column was 50∼305$^{\circ}C$, and methanol was a good GC solvent for both standard alizarin and madder extraction. The best extraction of madder was achieved by 90 min soaking in room temperature followed by filtration and the actual heat extraction procedure. The best pH for extracting alizarin was pH 3 and above pH 5 alizarin was not detectible. Only alizarin and no purpurin was found in the extraction of the currently used madder plant.