• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2687-2690
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• 2009

Due to the importance of isoflavone content in soybean extracts, the microwave-assisted process (MAP) was compared to the conventional extraction methods. For comparison of the three methods, all extraction parameters (solvent, sample to solvent ratio, temperature, etc.) were kept the same; the microwave extractor was operated at 187.5 W with an emission frequency of 2450 MHz under atmospheric pressure conditions and the extractions were carried out at 75 ${^{\circ}C}$ for 3 min while the conventional reflux was at 75 ${^{\circ}C}$ for 3 h. Total yield and crude isoflavone content were determined by ultraviolet spectrophotometric and compared with the three methods. Results indicated that the MAP was comparable to the conventional method in its capability to extract target compounds without causing any degradation; in addition it dramatically reduced the extraction time from 3 h to a few minutes, suggesting that it can be an alternative technique to the time-consuming conventional reflux method.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.2
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• pp.86-97
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• 2024

Alkaline- or salt-assisted extractions have been widely used to extract edible insect proteins, however, there is a need for extraction techniques that balance cost-efficient production as well as preserving the protein properties. Mealworm proteins (Tenebrio molitor larvae) were extracted using three different extraction methods-alkali (AMP), salt (SMP), and water (WMP)-and then physicochemical and techno-functional properties were examined. AMP had high yield, protein, and amino acid contents, whereas WMP had high moisture, ash, and fat contents. SDS-PAGE showed a wide range of molecular weights in WMP whereas mostly low molecular weights were observed in AMP and SMP. AMP had poor protein solubilities compared to SMP and WMP across all pHs. AMP had enhanced water-holding capacity and emulsion stability, whereas WMP had improved oil-holding capacity and foaming properties. WMP formed a gel with and without the transglutaminase. The physicochemical and techno-functional properties demonstrated that water-soluble mealworm protein was superior to alkali-and salt-soluble mealworm proteins. Considering the cost efficiency and minimal impact on the environment as well, a cold press juicer could be utilized for mass production of mealworm protein compared to the conventional methods of protein extraction using alkali and salt.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.259-269
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• 2021

The effects of the physicochemical properties of soil such as soil pH, cation exchange capacity, and organic matter content on single extraction of Cd, Cr, Cu, Ni, Pb, and Zn using CaCl2, HOAc, HNO3, and DTPA were statistically investigated for 69 agricultural soils in Korea. Correlation analysis and multiple regression analysis were applied for soil samples which were grouped on the basis of average values of the physicochemical properties of the soil. Diluted HNO3 extracted higher concentrations of Cr, Cu, Ni, and Pb when compared with the other extractants, however, similar amounts of Cd and Zn were extracted by HOAc with HNO3. The results of correlation analysis indicated that DTPA extraction showed a high correlation with other single and pseudo-total extraction methods, and the physicochemical properties of soil influenced the concentrations of heavy metals leached by the single extraction methods. In the case of Zn, high correlations between pseudo-total and the studied single extraction methods were observed. As a result of regression analysis, it was found that the physicochemical properties of the soil could explain up to 74% of variances of the single extraction results. These results indicate that the physicochemical properties of the soil can have a direct influence on the concentrations of heavy metals extracted by the single extraction methods.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.637-644
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• 2008

Four different extraction and purification methods were evaluated to determine the heterocyclic amines (HCAs) in fried pork patties. Pork patties were cooked in the teflon-coated electric frying pan at $230^{\circ}C$ for 8 min per side. HCAs in the fried pork patties were extracted and purified using four different solid-phase extraction (SPE) methods and quantitated by LC-MS (API-ESI). Recovery of four different extraction and purification methods was evaluated by comparing the HCAs amounts quantified by the standard addition method. Validation of extraction and purification methods for fried pork patties was determined to establish accurate sample preparation. The recoveries of HCAs from different SPE methods were calculated. The recovery yields were 15.7-68.7% (Polar amine group) and 25.0-74.7% (less-polar amine group) in method A. Method D provided recovery yields ranging from 14.1% to 68.7% in polar amine groups and from 3.0% to 72.3% in less-polar amine groups, respectively. Modified procedures of Method A and D were the most suitable extraction and purification method for HCAs analysis from fried pork patties.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.282-287
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• 2001

This study was carried out to investigate the difference of ginsenoside compositions in crude ginseng saponins prepared by five different methods including three new methods. Two known methods are hot methanol(MeOH) extraction/n-butanol(n-BuOH) fractionation and hot MeOH extraction/Diaion HP-20 adsorption/MeOH elution. Three new methods are hot MeOH extraction/cation AG 50W $absorption/H_2O$ elution/n-BuOH extraction, cool MeOH extraction/Diaion HP-20 adsorption/MeOH elution and direct extraction with ethyl acetate(EtOAc)/n-BuOH. Analysis of ginsenoside composition in the crude saponins by conventional HPLC/RI(Refractive Index) did not show great difference between methods except EtOAc/n-BuOH method. However, HPLC/ELSD (evaporative light scattering detector) employing gradient mobile phase afforded fine resolution of ginsenoside Rf, $Rg_1$ and $Rh_1$, and great difference of ginsenoside compositions between methods. LC/MS revealed that large amount of prosapogenins were produced during the pass through the cation exchange (AG 50W) column being strongly acidic. Six major ginsenosides such as $Rb_1,w;Rb_2,$ Rc, Rd, Re and $Rg_1$, 5 prosapogenins and one chikusetsusaponin were identified by LC/MS. A newly established HPLC method employing ODS column and gradient mobile phase of $KH_2PO_4/CH_3CN$ revealed that malonyl ginsenosides were detected only in the crude saponin obtained from cool MeOH extraction.

• Korean Journal of Medicinal Crop Science
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• v.24 no.1
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• pp.47-54
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• 2016

Background : A new extraction method-heated ultrasonic extraction was qualitatively and quantitatively analyzed for the extraction of major ginsenosides from ginseng extract; this new high-performance liquid chromatography (HPLC) method was compared with the official extraction method of Korean industrial standards and standard for health functional food. Methods and Results : Ginsenoside compounds were analyzed for 35 minutes by the new HPLC analysis method using a Halo$^{(R)}$ RP-Amide column. The new HPLC analysis method was validated by the measurement of intra-day and inter-day precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) of each ginsenoside. The correlation coefficients (r2) for the calibration curves of the ginsenoside compounds were over 0.9997 in terms of linearity. The heated ultrasonic extraction method using ultrasonication for 30 minutes at $50^{\circ}C$ yielded higher amount of ginsenosides than the extraction method of the Korean industrial standards owing to the enhancement of extraction efficiency. Conclusions : Compared to the other extraction methods, the heated ultrasonic extraction method yielded a higher amount of ginsenoside Rb1 than Rg1 index compounds for the quality evaluation of ginseng roots.

• 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.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.1-6
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• 2013

Objectives : In other to determine the optimal extraction conditions, the various Bojungikgi-tang (BJIGT) decoctions prepared by different pressure levels and different extraction times were compared and evaluated in terms of the extract yield and the total soluble solid content. Methods : Decoctions were prepared by the pressure levels of 0 (non-pressurized) and 1 $kgf/cm^2$ (pressurized) for 60, 120 and 180 min. The extract yield and the total soluble solids content of decoctions were measured, and the amounts of the reference compounds in decoctions were investigated by the analysis using high performance liquid chromatography. Results : The extract yield and the total soluble solid content were higher in decoctions extracted by the pressurized method than those from decoction with non-pressurized method. The patterns of yield and contents showed a proportional increase to the extraction time. In analysis of the linear regression for four reference compounds such as liquiritin, nodakenin, hesperidin, and glycyrrhizin, the good linearity with the correlation coefficient more than 0.9999 was observed. The highest contents for four reference compounds were observed at 180 min of both the pressurized method and the non-pressurized method. Conclusions : This study suggests that the pressure in extraction method and the extraction time affect the compositional constituents in BJIGT decoctions. The extraction time of 180 min could be chosen in both pressurized and non-pressurized method as optimal extraction condition.

• Journal of Environmental Science International
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• v.12 no.4
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• pp.447-459
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• 2003

This study was carried out to develop an efficient process far the elimination of phenol pollutant from soils. An microwave-assisted process (MAP) and a conventional Soxhlet extraction method (SEM) were employed to extract phenol from two types of soils. The effects of extraction methods, aged time of the spiked soil samples, extraction solvent and extraction time on the extraction performance were compared. Our results demonstrate that the recoveries from standard soil spiked were at least 10% higher fer MAP than these f3r the conventional Soxhlet. The extraction time by MAP requires significantly shelter time (1 min) than 15 h of the conventional Soxhlet. The recoveries from non-contaminated soil spiked with phenol were also almost identical f3r above results. The reduction of the extraction times with efficiency higher than that afforded by the conventional Soxhlet technique supports the suitability of the MAP method.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.4
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• pp.42-53
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• 2012

In pattern recognition and machine learning society, classification has been a classical problem and the most widely researched area. Adaptive boosting also known as Adaboost has been successfully applied to binary classification problems. It is a kind of boosting algorithm capable of constructing a strong classifier through a weighted combination of weak classifiers. On the other hand, the PCA and LDA algorithms are the most popular linear feature extraction methods used mainly for dimensionality reduction. In this paper, the combination of Adaboost and feature extraction methods is proposed for efficient classification of two class data. Conventionally, in classification problems, the roles of feature extraction and classification have been distinct, i.e., a feature extraction method and a classifier are applied sequentially to classify input variable into several categories. In this paper, these two steps are combined into one resulting in a good classification performance. More specifically, each projection vector is treated as a weak classifier in Adaboost algorithm to constitute a strong classifier for binary classification problems. The proposed algorithm is applied to UCI dataset and FRGC dataset and showed better recognition rates than sequential application of feature extraction and classification methods.