• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.6
• /
• pp.537-546
• /
• 1986

In the previous paper(Kim et al, 1986), the alkaline proteinase from the pyloric caeca of mackerel was shown relatively strong activity in the alkaline pH range. Therefore purification of the enzyme has been undertaken to identify the proteolytic enzyme and three alkaline proteinases were isolated by ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration. One percent sodium chloride solution was the most effective for the extraction of alkaline proteinase from the pyloric caeca of mackerel. Three alkaline proteinases temporarily designated Enz. A, B and C were isolated from the pyloric caeca of mackerel, and identified to be homogeneous with electrophoresis. The specific activity of the purified Enz. A, B and C was increased to 34, 53 and 37-fold over the crude enzyme solution, respectively. Yield of them was 1.6, 2.1 and $1.5\%$, respectively, and a combined yield was $5.2\%$.

• Food Science and Preservation
• /
• v.11 no.3
• /
• pp.352-357
• /
• 2004

The present study was conducted to investigate extraction characteristics and antioxidative activity of Lycium chinense extracts. Lycium chinense were extracted by reflux extraction(RE) under different extraction conditions including solvent. The solid yield, turbidity, color value, titratable acidity, free sugar contents, electron donating ability(EDA) and superoxide dismutase(SOD)-like ability of Lycium chinense extracts were determined. The highest solid yield value were obtained with water of 10 fold. No significant difference in turbidity and color value were found among the extracts prepared with various extraction solvents, 75$\%$ ethanol, 50$\%$ ethanol and water. The highest titratable acidity were obtained with water of Lycium chinense. The free sugar contents of Lycium chinense extracted with water showed the highest value. Lycium chinense extracts with water included higher contents of free sugar compared with those of the other solvent extracts, 50$\%$ ethanol and 75$\%$ ethanol extracts. The total polyphenol compounds content of Lycium chinense extracted with 50% ethanol showed the highest value. Lycium chinense extracts with 50$\%$ ethanol included higher contents of total polyphenol compound compared with those of the other solvent extracts, water and 75$\%$ ethanol extracts.

• Korean Journal of Food Science and Technology
• /
• v.29 no.1
• /
• pp.183-187
• /
• 1997

The analytical conditions of 1,3-dichloro-2-propanol (DCP) and 3-chloro-1,2-propanediol (MCPD) by solid phase extraction were optimized to improve recovery. Selected-ion monitoring technique which was used for GC-MS analysis of both compounds gave substantially higher sensitivity. The detection limits of DCP and MCPD were 25 and 50 ppb, respectively. The effects of extraction column type, elution solvent and salt concentration on recovery were examined. A normal phase column was better than a reverse phase column in solid phase extraction of DCP and MCPD. It was explained in terms of polarity relationship of solvent-solute-solid phase. A maximum recovery was obtained at the salt concentration of 20% (w/v). Water-immiscible and chloropropanol-soluble solvents such as chloroform, diethyl ether, hexane and ethyl acetate were tested for elution solvent. Hexane and ethyl acetate were the most suitable solvents for the extraction of DCP and MCPD, respectively. High recovery better than 95% was obtained with the selected solvents.

• Korean Chemical Engineering Research
• /
• v.53 no.6
• /
• pp.792-797
• /
• 2015

Graphene has a wide spectrum on its application field due to various and excellent physical properties. However, it is very difficult to apply that graphene exists as lump or fold condition in general organic solvents. Besides, graphene was difficult to maintain as uniform condition due to chemical inert and distributions with various size and shapes. Therefore, this study was focused to study dispersion and modifying methods of aggregated graphene. The dispersion methods contain as follow: i) physical milling using glass bead, ii) co-treatment of glass bead and ultrasonic waves, iii) dispersion in organic solvents, iv) modifying with dry-ice. Milling using glass bead with size 2.5 mm was effective to be size decrease of 36.4% in comparison with control group. Mixed treatment of glass bead (size 2.5 mm) and ultrasonic waves (225W, 10 min) showed relative size decrease of 76%, suggesting that the size decrease depends on the size of glass bead, intensity of ultrasonic waves and treatment time. Solvents of Ethyl acetate (EA) and Isoprophyl alcohol (IPA) were used in order to improve dispersion by modifying surface of graphene. IPA of them showed a favorable dispersion with more -CO functional groups in the FT-IR analysis. On the other hand, the oxygen content of graphene surface modified by dry-ice was highly increased from 0.8 to 4.9%. From the results, it was decided that the favorable dispersion state for a long time was obtained under the condition of -CO functional group increase in IPA solvent.

• Food Science and Preservation
• /
• v.15 no.1
• /
• pp.66-73
• /
• 2008

Response surface methodology (RSM) was applied for monitor the yields of desirable substances from fig (Ficus carica L) under different extraction conditions. The maximum yield was 66.46% at 22.08 mL/g of solvent to sample ratio, $90.59^{\circ}C$ extraction temperature and 148.04 min extraction time. The maximum total phenolics was $121.31{\mu}g/mL$ at 17.87 mL/g, $98.82^{\circ}C$, and 130.80 min. The maximum electron donating ability was 54.09% at $121.31{\mu}g/mL$, 18.13 mL/g, and $98.81^{\circ}C$. The maximum value of protease activity was 54.51 unit/min at 17.45 mL/g, $99.01^{\circ}C$, and 131.43 min. In addition, the maximum value of reducing sugar content was 19.14 mg/mL in 22.66 mL/g, $86.30^{\circ}C$, and 153.59 min. The optimum conditions estimated by RSM for maximal extraction of the effective components were $17{\sim}25$ mL/g of solvent to sample ratio, $80{\sim}100^{\circ}C$ of extraction temperature, and $100{\sim}170$ min of extraction time.

• Nuclear Engineering and Technology
• /
• v.13 no.4
• /
• pp.221-228
• /
• 1981

${\gamma}$-(U-$^{14}$ C)-BHC was applied to rice plants grown in a pot and its fate in the growth, polishing and oil-extraction processes of the grain was investigated. The $^{14}$ C-activity was absorbed and translocated widely in the plant and the recovery of applied $^{14}$ C-activity in the straw and grain was about 2.8%, of which 9.4% was found in the brown rice. The % partitioning of $^{14}$ C-residues in bran and polished rice was 12:88 and that in oil and oilcake was 37 : 63. Characterization of $^{14}$ C-residues indicated the presence of ${\gamma}$-BHC, pentachlorocyclohexene, trichlorobenzene and hydrophilic metabolites, whose proportions were different in the straw and grain.

• Transactions of the Korean hydrogen and new energy society
• /
• v.16 no.2
• /
• pp.159-169
• /
• 2005

Cellulose, consisted of 45 wt% in wood, is usable as fuels and heavy oil additives if depolymerized to monomer unit, because the chemical structures are similar to high octane materials found in gasoline. In this study, thermochemical degradation by solvolysis reaction of cellulose such as the effect of reaction temperature, reaction time and type of solvent on conversion yield and degradation products were investigated. It was found that the effectiveness of the solvent on the sovolysis reaction was as follows; acetone>n-butanol>tetralin. When acetone was used as a solvent, the highest cellulose conversion was observed to be 91.8% at 500$^{\circ}C$, 40min. Combustion heating value of liquid products from thermochemical conversion processes was in the range of 7,330${\sim}$7,410cal/g. The energy yield and mass yield in acetone-solvolysis of cellulose was as high as 66.8% and 37.0 g oil/100g raw material after 40min of reaction at 400$^{\circ}C$. Various aliphatic and aromatic compounds were detected in the cellulose solvolysis products. The major components of the solvolysis products, that could be used as fuel, were mesityl oxide, mesitylene, isophorone.

• Applied Biological Chemistry
• /
• v.16 no.2
• /
• pp.53-59
• /
• 1973

The anthocyanins in Santa rosa plum (widely growing var. in Korea) were extracted with 0.5% methanolic HCl and purified with Amberlite IRC-50 cation exchange resin. The individual pigments were separated by paper chromatography. The two pigments were identified as cyanidin-3-monoglucoside and cyanidin-3-xyloglucoside based on the following evidence: Rf values in various solvents, partical acid hydrolysis, stepwise hydrolysis, sugar moiety, alkaline degradation, and absorption spectra in the visible region. Cyanicin-3-monoglucoside was the abundant pigment of the plum.

• Journal of the Korean Chemical Society
• /
• v.34 no.3
• /
• pp.221-226
• /
• 1990

The solvolysis of substitued phenacyl tosylates was studied in binary solvent mixtures of methanol-acetonitrile and methanol-acetone at 55$^{\circ}C$. Except for m-nitrophenacyl tosylate, the rate constants were increased with both of electron-donating substituents and electron-withdrawing ones and its rate constants were the largest in the binary solvent mixtures of 90% MeOH-10% MeCN. The results show that the reactions were changed with dissociative $S_N2$ mechanism judging from the magnitude of 1/m values going from the electron-withdrawing group to the electron-donating one of the substrate. And above results were consisted with the account for the PES model and QM approach.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.140.2-140
• /
• 2003

국산(2, 3년생) 및 중국산 음나무의 껍질을 이용해 음나무 껍질의 추출물에 대해 용매는 열수, 추출시간 및 추출온도는 각각 7시간, 9$0^{\circ}C$의 조건으로 추출하여 색도, 갈색도, 가용성고형분, 총페놀성화합물, 전자공여능, 조사포닌 및 환원당을 분석하였다. 원산지별 음나무 껍질 추출물의 색도에서는 명도(L)는 국산이 중국산 보다 조금 높게 나타났다. 그러나 적색도(a)는 중국산 음나무 수피의 추출물이 적색도가 높았으며 황색도(b) 역시 중국산 추출물이 가장 높은 것으로 나타났다. 갈색도 역시 국내산에 비해 중국산이 높은 수치를 나타내는 경향을 보였다. 가용성고형분의 경우 국산이 중국산 음나무 껍질 추출물에 비해 가용성고형분의 함량이 높게 나타났으며 국산에서는2, 3년생에서 큰 차이를 보이지 않았다. 총페놀성화합물의 경우에서도 중국산 보다 국산 음나무 껍질 추출물의 함량이 더 높게 나타났으며 그 중에서도 특히 국산 2년생이 가장 높은 값을 나타내었다. 전자공여능은 국산 및 중국산 음나무에서 그다지 큰 차이를 보이지 않았으나 국산이 약간 더 높은 경향을 보였다. 환원당의 경우 중국산에 비해 국산이 높은 함량을 보였으며 국산에서는 그다지 큰 차이를 나타내지 않았다. 조사포닌의 경우 다른 추출물에 비해 국산 2년생 추출물이 가장 높은 함량을 나타내었으며 특히 조사포닌의 경우 그 함량이 일반 인삼의 1/3 정도의 함량을 나타내고 있어 기능성을 기대해 볼 수 있을 것이다.