• Food Engineering Progress
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• v.21 no.3
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• pp.256-266
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• 2017

This study was designed to optimize ethanol extraction process of unfertilized corn silk (UCS) to maximize phytochemical contents and bioactivities. The response surface methodology (RSM) with central composite design (CCD) was employed to obtain the optimal extraction conditions. The influence of ethanol concentration, extraction temperature and extraction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activities and tyrosinase inhibition were analyzed. For all dependable variables, the most significant factor was ethanol concentration followed by extraction temperature and extraction time. The following optimum conditions were determined by simultaneous optimization of several responses with the Derringer's desirability function using the numerical optimization function of the Design-Expert program: ethanol concentration 80.45%, extraction temperature $53.49^{\circ}C$, and extraction time 4.95 h. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, DPPH radical scavenging activity and tyrosinase inhibition were $2758.74{\mu}g\;GAE/g$ dried sample, $1520.81{\mu}g\;QUE/g$ dried sample, 810.26 mg/100g dried sample, 56.86% and 43.49%, respectively, and the overall desirability (D) was 0.74.

• Food Science and Preservation
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• v.9 no.3
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• pp.332-337
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• 2002

This study was undertaken in order to compare reflux extraction(RE) and microwave-assisted extraction(MAE) in extraction efficiency and establish optimum microwave extraction conditions in obtaining Ligularia fischeri extracts. A considerable reduction in extraction time was accomplished by MAE. When 70% methanol 50% methanol 70% ethanol, or 50% ethanol was used, MAE extract contained equal levels of soluble solid and total polyphenol as obtained by RE. The optimum microwave-assisted extraction conditions for Ligularia fischeri were achieved by 120∼150 watts of microwave energy and 4∼8 minutes of extraction time. No significant changes were found in antioxidant activity with DPPH scavenging method over the variation of microwave energy or extraction time. The use of diluted methanol or ethanol improved soluble solid content(30%), total polyphenol content(2.7%) and antioxidant activity(68%).

• Food Science and Preservation
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• v.11 no.1
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• pp.88-93
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• 2004

This study was conducted in order to compare reflux extraction(RE) and microwave-assisted extraction(MAE) in extraction efficiency and establish optimum microwave extraction conditions in obtaining Aster scaber Thunb extracts. Extraction time was reduced considerably in MAE. When 70％ methanol, 50％ methanol, 70％ ethanol, or 50％ ethanol was used, no difference was found in the amount of soluble solid and total phenol between MAE and RE. The optimum microwave-assisted extraction conditions for Aster scaber Thunb were achieved by 120-150 watts of microwave energy and 4∼8 minutes of extraction time. No significant changes were found in antioxidant activity using DPPH scavenging method over the variation of microwave power or extraction time. The use of diluted methanol or ethanol improved soluble solid content(30.8％), total polyphenol content(2.9％) and antioxidant activity(69％ ).

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.527-534
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• 2021

The demand for sustainable extraction of bioactive compounds from food matrices has been increasing. Water extraction of anthocyanins in aronia was investigated using conventional and ultrasonic-assisted methods. The optimum extraction conditions for the conventional method included a sample-to-water ratio of 1:40 g/mL, extraction temperature 71℃, and extraction time of 39 min. The optimized conditions for ultrasonic-assisted extraction were a sample-to-water ratio of 1:40 g/mL, extraction temperature 80℃, extraction time of 20 min, and an amplitude of 87.2 ㎛. The anthocyanin contents of the two extracts were 155.32 and 158.02 mg/100 g fresh weight, respectively. The major anthocyanins were cyanidin 3-galactoside (65% of the total) and cyanidin 3-arabinoside (30% of the total). The contents of individual anthocyanins and phenolic acids were not significantly different between the two optimized extracts.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.809-827
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• 2017

Steam explosion was applied to extract phenolic compounds from oak wood (Quercus mongolica). The effects of three independent factors (ethanol concentration, extraction temperature and extraction time) on the total phenolic content, DPPH radical scavenging activity, and antimicrobial activity from the steam exploded oak wood were optimized using response surface methodology (RSM). The independent variables were coded at three levels and their actual values were selected on the basis of preliminary experimental results. The following optimal extraction conditions were selected: ethanol concentration 82.0%, extraction temperature $71.7^{\circ}C$, and extraction time 60.5 min for total phenolic content; ethanol concentration 78.3%, extraction temperature $70.3^{\circ}C$, and extraction time 57.6 min for DPPH radical scavenging activity; ethanol concentration 80.6%, extraction temperature $68.4^{\circ}C$, and extraction time 59.0 min for antimicrobial activity. The experimental values agreed with those were predicted within confidence intervals indicating the suitability of RSM in optimizing the ethanol extraction of phenolic compounds from the steam exploded oak wood. Under the optimized conditions, the experimental value of the total phenolic content was 111.8 mg GAE/g dry steam exploded oak wood, DPPH free radical scavenging activity was 65.7%, and antimicrobial activity was 17.0 mm, and those are reasonably close to the predicted values (109.2 mg GAE/g dry steam exploded oak wood, 62.3% and 15.9 mm, respectively).

• Journal of the Korean Society of Food Culture
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• v.23 no.6
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• pp.667-680
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• 2008

The moisture contained in conventionally extracted red crab shell samples was lower than than in samples extracted using high pressure. In contrast, ash content increased as the extraction time increased and displayed no significant variation in high pressure extraction. Extraction time was influential, with lower lightness (L-value) being obtained in samples extracted at high pressure as compared to traditional extraction. However, large variation in a- and b-values resulted from traditional extraction. For both traditional and high pressure extraction increases in pH, salinity and saccharide content were noted with increasing extraction time, but these parameters did not vary substantially in red crab shell extracted at high pressure. The mineral content in samples extracted by high pressure was higher than in traditionally extracted samples. The mineral content increased with time, with marginally higher contents of essential amino acids and flavor enhancing amino acids noted following high pressure extraction. The contents of the flavor enhancing amino acids increased from 30?60 min, thereafter decreasing. Assessment of consumer acceptance revealed that, while traditionally manufactured red crab sauce was popular, sauce manufactured using a 60 min high pressure extraction was preferred. Extending the high pressure extraction time to 75 min produced a less sensory acceptable product, due to higher mineral and protein levels.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1265-1272
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• 2011

In this study, the extraction characteristics of soluble solid from Rumex crispus(Curled dock) was studied from the investigation of the effects of experimental conditions on extraction rate; extraction ratio, composition of extractants, extraction time and pH of extractant, etc. The proximate composition of Rumex crispus was 2.58% crude lipid, 5.59% crude protein, 7.39% crude ash, 6.13% moisture and 78.31% carbohydrate, respectively. Turbidity of extract by distilled water was higher and increased with extraction time and extraction temperature, where as the turbidity didn't increase by ethanol and methanol in 20 folds of extraction ratio. Turbidity was inversely proportional to the extraction ratio for the three extractants at 25$^{\circ}C$ and 1 hour extraction. But turbidity of extract was highest by composition of 50% methanol-water extractant than any other compositions of extractants. Eighteen and fifteen free aminoacids were detected in extracts with distilled water, methanol and ethanol extractant, respectively, and it's contents were order of glutamic acid>proline>aminobutyric acid>alanine. The extraction rate of soluble solid from Rumex crispus was order of distilled water>methanol>ethanol within experimental extraction ratio. In extraction with distilled water, the contents of soluble solid was inversely proportional to the pH of extractant.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.2
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• pp.113-118
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• 2013

In this study, silk sericin films were prepared using different extraction methods, and the molecular conformation of sericin was examined using Fourier-transform infrared spectroscopy with attenuated total reflection geometry. Additionally, the effect of the film side (air-facing side or plate-facing side) on the molecular conformation of the sericin films was investigated. Interestingly, the molecular conformation of the sericin film depended on the film side. The molecular conformation of air-facing side of the sericin film was significantly influenced by extraction solution and time. The ${\beta}$-sheet crystallization and the crystallinity index of the sericin film markedly increased with an increase in the extraction time in hot water. The order of the crystallinity indices for the sericin films obtained with different extraction solutions was as follows: citric acid solution > urea solution >> hot water. In contrast, no remarkable differences were observed in the molecular conformation of the plate-facing side of the sericin film after extraction in hot water for different time periods. Urea and citric acid solution extractions showed remarkably higher crystallinity indices for sericin than those obtained after hot water extraction. However, no significant differences were observed in the crystallinity index of sericin between urea and citric acid solution extraction in plate-facing side of the film.

• Analytical Science and Technology
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• v.17 no.4
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• pp.295-301
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• 2004

In this study, static and dynamic solvent extractions are compared for more efficient extraction of polychlorinated dibenzofurans (PCDFs) from fly ash. Static solvent extraction rather than dynamic extraction showed a higher recovery of PCDFs, which was adsorbed strongly with fly ash. The effects of parameters, such as temperature, toluene-isopropyl alcohol mixture, static and dynamic time flow rate, and solvent volume on the extraction were investigated and the variations in average recoveries of PCDFs were explained. In both extractions, temperature was an effective parameter because the higher temperature gave the higher recoveries. In dynamic solvent extraction, dynamic time was more effective than flow rate and solvent volume for the extraction of PCDFs from fly ash. Multi-layer column chromatography on neutral and acidic silica gel with n-hexane was used for cleaning up the extracts. The quantification of the PCDFs extracted was performed using HPLC-UV.

• Journal of Ginseng Research
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• v.3 no.1
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• pp.40-53
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• 1979

In order to investigate the optimal conditions which affects to extraction of ginseng extract and saponin in ginseng extract, experiment was carried out varing with ethanol percentage, extraction time, temperature, sol$.$vent and Plant Parts. The results art as follows: 1. The amounts of ginseng saponin was increased according to increanation of ethanol Percentage while the amounts of ginseng extract was decreased. 2. The amounts of ginseng extract was increased as the prolongation of extraction time, on the ether hand, ginseng saponin contents increased lentil 40hr. and decreased after that. 3. By the raise of extract temperature, both of the amounts of ginseng saponin and ginseng extract was increased two times and four times. respectively. 4. The total amounts ginseng extract was obtained 22.86u when the water used as the extraction solvent, 11.28% on ethanol and 11.04U on methanol, in the order. and the saponin contents gained when the extraction solvents of water, methanol and ethanol 7.47%, 12.36% and 12.77%, respectively. 5. It showed 9.23% of ginseng extract in epidermis and 8.4% of ginseng saponin in tail Part of raw ginseng and in the case of dried ginseng, ginseng extract and saponin showed the most amounts in epidermis of 18.28% and 19.35%, respectively. 6. The ratio of panaxadiol and panaxatriol contents of ginseng saponin was almost same when it was extracted varing with ethanol percentage and extraction time (duration), and the more alcohol percentage and the longer extraction time increased, the more fractional content of ginseng saponin was extracted.