• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.117-124
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• 2000

Considering the thermal unstableness of ginseng components, microwave-assisted extraction(MAE) was performed under the atmospheric pressure condition. The monitoring of extraction characteristics and the optimization of extraction conditions were made by response surface methodology. The extraction efficiency of soluble ginseng components was high at lower ethanol concentration and at higher microwave power, while crude saponin content was easily extracted at higher ethanol concentration. Estimated conditions for the maximized extraction of soluble components including crude saponin, total phenolics and electron donating ability were $54{\sim}60%$ in ethanol concentration, $41{\sim}90$ W in microwave power, and within 4 min in extraction time. Predicted values at the optimum condition(60% ethanol, 80 W microwave power and 4 min extraction time) were in good agreement with observed values.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.379-383
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• 2008

Extraction characteristics of garlic and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 26.41% was obtained at microwave power of 146.29 W, ethanol concentration of 63.31 %, and extraction time of 5.88 min. At microwave power, ethanol concentration, and extraction time of 114.84 W, 58.83%, and 1.42 min, respectively, maximum electron-donating ability (EDA) was 72.86%. Maximum nitrite-scavenging ability was 94.62% at microwave power, ethanol concentration, and extraction time of 81.83 W, 2.65%, and 3.83 min, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 49.12% at microwave power of 34.23 W, ethanol concentration of 33.11 %, and extraction time of 4.40 min. Based on superimposition of 4-dimensional RSM with respect to extraction yield, electron-donating ability, nitrite-scavenging ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were microwave power of 0-100 W, ethanol concentration of 40-70%, and extraction time of 2-8 min.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.574-577
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• 2017

In Indonesia, vetiver oil is one commodity that plays an important role in the country's foreign exchange earnings. Currently, the extraction of essential oil from vetiver still uses conventional methods. Therefore, the aim of this study was to know and verify the kinetics and mechanism of microwave hydrodistillation of vetiver based on two models. In this study, microwave hydrodistillation was used to extract essential oils from vetiver. The extraction was carried out in nine extraction cycles of 20 min to 3 hours. The rate constant, the equilibrium extraction capacity, and the initial extraction rate were calculated using the two models. Kinetics of oil extraction from vetiver by microwave hydrodistillation proved that the extraction process was based on the second-order extraction model. The second-order model was satisfactorily applied, with high coefficients of correlation ($R^2=0.9427$), showing that it well described the process.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.222-228
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• 2003

Optimum extraction conditions for yield, browning color, electron-donating ability, nitrite-scavenging effect, total polyphenol content, and tyrosinase-inhibitory activity of Flammulina velutipes were determined using response surface methodology through central composite design. Yield of F. velutipes was affected by ethanol concentration, and browning color improved more with the increase of ethanol concentration than microwave power. Nitrite-scavenging effect was improved with increasing ethanol concentration and decreasing microwave power. Electron-donating ability and total polyphenol content were improved with increasing ethanol concentration and microwave power. Tyrosinase-inhibitory effect increased more with decrease in microwave power than with ethanol concentration. The optimal range of extraction conditions for effective component of F. velutipes were $47.21{\sim}76.05$ watt of microwave power, $10.25{\sim}43.56%$ of ethanol concentration, and 5.72 min of extraction time.

• Food Science and Preservation
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• v.12 no.4
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• pp.344-349
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• 2005

Microwave-assisted process (MAP) was applied to extract antioxidant-related components from Thymus quinquecostatus var. japonica Hara. Microwave power(2,450 MHz, $0{\sim}160$ W) and extraction time($1{\sim}5\;min$) were used as independent variables($X_i$) for central composite design to yield 10 different extraction conditions. Response surface methodology was applied to predict optimum extraction conditions for dependent variables of extracts, such as total yield, total phenolics, flavonoid, and electron donation ability depending on different powers and extraction times of MAP. Determination coefficients($R^2$) of regression equations for dependent variables were higher than 0.93 excluding that of total phenolics, and microwave power was predicted more influential than extraction time in MAP (p<0.05). The optimal extraction time for each dependent variable was ranged from 3.36 to 4.97 min, but microwave power showed wide ranges depending on variables. The superimposed contour maps for maximized dependent variables illustrated extraction conditions of 64 to 100 W in microwave power and 2.9 to 4.0 min in extraction time.

• Elastomers and Composites
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• v.33 no.3
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• pp.201-209
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• 1998

Alumina powders used as a filler in rubber compounding was extracted from kaolin in $H_2SO_4$ solution employing conventional thermal and microwave energy resources. Maximum degrees of alumina extraction from kaolin were 72.8% at $80^{\circ}C$, 1M $H_2SO_4$, and 180min in the conventional thermal extraction process and were 99.0% at $90^{\circ}C$, 1M $H_2SO_4$,, and 60min in the microwave extraction one, respectively. The samples synthesized in both processes were analyzed by means of TG/DTA, XRD, SEM, Atomic Emission Spectroscopy, and BET method. Studies are presently under way to unravel the basic interaction mechanisms between microwave and alumina power for high rates of alumina extraction from kaolin in the microwave ex-traction process.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.285-291
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• 2005

Effects of the aqueous or 50% ethanolic extracts prepared by various extraction procedures on macrophage activation were determined by using the mouse macrophage cell line RAW264.7 cells as a indicator cell. The results demonstrated that the fractions prepared by aqueous extraction for 2 h and by microwave extraction with 50% ethanol at 60 W for 3 min had the greatest inducing abilities for NO production, and that the greatest ROS scavenging abilities were found in the fractions prepared by hot water extraction for 2 h or 3 h, by microwave extraction with 50% ethanol at 60 W for 3 min and by 0.5% HCl extraction, respectively. Phagocytotic activities against Candida albicans were found to be highest for the 50% ethanolic extracts prepared by microwave extraction for 3 min at 60 W, 80 W and 12 W, respectively. Especially, we found that a extract prepared by microwave extraction with 50% ethanol at 60 W for 3 min enables to induce effectively overall functional activation of macrophage, such as NO production, ROS scavenging and phagocytosis of C. albicans, respectively. These results demonstrated that a 50% ethanolic extraction using microwave at 60 W for 3 min would be useful for enrichment of macrophage-activating components contained in Hericium erinaceus, implying participation of protein-bound polysaccharides as a active factor.

• Food Science and Preservation
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• v.12 no.2
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• pp.130-134
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• 2005

This study was conducted to investigate the effects of pretreatment and extraction methods on the water extraction yields of sugar, protein and phenolic compounds, and the antioxidative activity of extract from Ganoderma lucidum. The herb was ground, sifted, and treated for 10 min with microwave (2,450 MHz) and ultrasound (20 kHz), and then extracted by boiling underatmospheric pressure and pressured boiling. Particle size $(0.8\~2.4\;mm)$, extraction time (2 hr) and solvent/solid ratio (20:1) were selected as optimal conditions for extraction.. Microwave and ultrasound treatment increased the extraction yields of total sugar, protein and phenolic compounds and the radical scavenging activity of extract. In comparison with microwave treatment and ultrasound treatment, microwave treatment was more effective than that of ultrasound treatment. The yields of all three compounds and the radical scavenging activity of extract were higher in pressured boiling extraction than in boiling underatmospheric pressure. The results showed that microwave radiation and sonication prior to extraction, and pressured extraction could be utilized for improving the extraction efficiency of G. lucidum.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.273-279
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• 2020

In this study, conventional solvent extraction (CSE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE) were compared for the recovery of paclitaxel from biomass. As a result of investigating the effect of the extraction solvent type (acetone, chloroform, ethanol, methanol, methylene chloride), methanol was the most suitable for all extraction methods. In the case of MAE and UAE using methanol, most of the paclitaxel (> 95%) was recovered by only one extraction. The recovery rate of paclitaxel increased with the increase of extraction temperature (25-45 ℃), microwave power (50-150 W), and ultrasonic power (180-380 W) for MAE and UAE. In addition, SEM analysis showed that the biomass surface structure was slightly corrugated in CSE, while in the MAE and UAE, it was very rough and destroyed by strong impact.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1431-1436
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• 2007

In order to optimize the extract condition and improve physiological activity of the extract form Tricholoma matsutake, experiments related to extraction methods, totale yield, content of total soluble polysaccharide, SOD-like activity, total polyphenol amount, and volatile flavor compound and the others were carried out, results were obtained as following: Compare with traditional hydrothermal extraction method (Hot water extraction : HWEW), it illustrates that the low temperature extraction method which combines a supersonic waves and microwave (Supersonic microwave extraction : SMEW) causes of increasing the total yield, total soluble polysaccharide. As to the anti-oxident effect, SMEW method leds to increasing of the SOD-like activity, total polyphenol amount as well. Also, cytotoxic effect and growth inhibitory effect against cancer cell line are much higher in SMEW method than HWEW method, especially SMEW5 extracts treated by supersonic 15 min. and microwave 120W, 3 min. and 2 times. The main volatile flavor compound and infinitesimal volatile flavor compound both increase significantly by SMEW method. It is concluded the main components of the volatile flavor compounds extracted from Tricholoma matsutake are 1-octen-3-0l, Methyl cinnamate, 2-octeno1 et al. alcohol typies. Consequently, SMEW5 method is considered as the most effective one for anti-oxidant and is prior to any other methods. And the optimun conditions of this method are : supersonic waves (supersonic, 25KHz, 50W) 15 minutes, microwave spectroscopy (microwave, 2,450MHz, 120W) 3 minutes, and every treatment is performed once followed twice repeats.