• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1256-1260
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• 1997

A series of acyclic polyethers bearing amide end-groups and lipophilic alkyl chains (3-5) were successfully synthesized with quantitative yields. Based upon the transport experiment in a bulk liquid membrane (BLM) system and solvent extraction, a very high selectivity of Pb2+ over other transition metal cations was observed. Measurement of thermodynamic parameters for complexation in methanol at 25 ℃ gave a strong evidence for excellent selective complexation for lead ion over other transition metal ions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1343-1349
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• 2017

This study was carried out to determine the simultaneous extraction conditions of functional components (lutein, ${\beta}$-carotene, total polyphenol, flavonoids, and phenolic compounds) from sweet potato leaves and to evaluate the antioxidant activities. Extraction conditions included different ethanol concentrations (1st extraction: 99.9% ethanol; 2nd extraction: 50~90% ethanol) and times (30, 60, and 90 min). The highest values of lutein and ${\beta}$-carotene content were obtained by the 2nd extraction at an ethanol concentration of 90%. The extraction yields of lutein and ${\beta}$-carotene decreased with increasing extraction time. The maximum polyphenol, flavonoid, and total phenolic acid contents and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities were 32.3 mg gallic acid equivalent/g, 17.0 mg catechin equivalent/g, 2,842.6 mg/100 g, 17.0 mg ascorbic acid equivalent/g, and 1.94 mg/mL ($IC_{50}$) at the 2nd extraction with an ethanol concentration of 60%. The optimum extraction conditions were as follows; ethanol concentrations of the extraction solvent were 99.9% (1st extraction) and 60% (2nd extraction), and extraction time was 30 min.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.93-102
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• 1992

In order to reduce long preparating time for alkali pretreated B-type gelatin, enzyme pretreatment was tried on flounder(Limanda aspera) skin for I-type gelatin. The optimal extraction conditions of the B-type gelatin were 9 folds of added water with material(w/w), 3 hrs of extraction time, $60^{\circ}C$ of extraction temperature and pH 5. The maximum amount of I-type gelatin was extracted at $60^{\circ}C$ for 3 hrs using water controlled to pH 6.0(material : water= 1:9, w/w). The yields of the B- and E-type gelatin were $64.2\%\;and\;59.2\%,$ respectively. The B-type was superior to the B-type in physical properties such as jelly strength, viscosity and electric conductivity. Molecular weight of B-type was so far larger than that of the E-type due to different pretreatment method. Hydrolysis ratio of the E-type was higher than that of the B-type because of its molecular weight. Results suggest that B-type product would be better than I-type as fish skin gelatin but E-type was desirable in hydrolyzate preparation.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1317-1325
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• 2013

Paulownia coreana is a medicinal, edible and industrial plant with the largest leaf, and is native to Korea. We evaluated the reducing power activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (RSAs), nitrite scavenging activities (NSAs) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation RSAs by solvent extraction of P. coreana bark by using $50^{\circ}C$ hot water and $25^{\circ}C$ methanol. The antioxidative effect of P. coreana bark extract on corn seed oil was evaluated using the Rancimat test. The extraction yields on dry weight basis with 15 folds of hot water and methanol were 23.88% and 5.30%, respectively; further the flavonoid content in the hot water extract was over 2.5 times more than that in the methanol extract. The DPPH RSA of the methanol extract was substantially higher than that of the water extract, whereas the NSA of the water extract was higher than that of the methanol extract at pH 1.2. The ABTS RSAs of the two extracts were almost the same as that of ascorbic acid and 2,6-ditertiarybutyl hydroxytoluene. The two extracts of P. coreana bark in this study were found to slightly improve the oxidation stability of corn seed oil.

• Culinary science and hospitality research
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• v.23 no.3
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• pp.166-173
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• 2017

This study was performed to compare the vitamin A, E, ${\beta}-carotene$, polyphenol content, and DPPH radical scavenging activity of carrot, apple, and blueberry juices as affected by extraction methods using slow juicer (HJ), no vacuum blending (NVJ) and vacuum blending (VJ). Juice yields of carrot, apple, and blueberry were 100% in NVJ and VJ groups. Vitamin A content of all juices was the highest in VJ group. Vitamin E content in carrot and apple juices increased most in the HJ group, followed by the NVJ and VJ group; Vitamin E content in blueberry juice was higher in the NVJ group than VJ or HJ group. ${\beta}-carotene$ and polyphenol content in all juices were highest in the VJ group. In addition, the differences between vacuum blending and non-vacuum blending were only shown on apple and blueberry juices. Polyphenol content in carrot and blueberry juices increased most in the HJ group, followed by the NVJ, and VJ groups, and in apple juice, polyphenol content was higher in the VJ group than the HJ or NVJ group. DPPH radical scavenging activity in the VJ group was significantly higher than the NVJ group. The results of this study showed the vacuum blending method had outstanding antioxidative nutrients compared to other juicing methods.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.351-359
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• 2016

Background: We investigated the optimal aqueous extraction conditions for recovery of high yields of total phenolic compounds from roots of Arctium lappa L. (burdock, Asteraceae), and we compared their antioxidant capacity. Methods and Results: The antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, and oxygen radical absorbance capacity assays. In addition, the major phenolic compounds present in the extracts were determined by high performance liquid chromatography analysis. Our results suggest that the roasted burdock $100^{\circ}C$, 15 min extract exhibited the strongest radical scavenging activity and possessed the highest concentration of phenolic compounds. The polyphenol content of both dried burdock and roasted burdock significantly increased with increase in the extraction temperature and time. Conclusions: These results indicated a relationship between phenolic compound levels in burdock and their free radical scavenging activities. This suggests that phenolic compounds significantly increase the antioxidant potential of burdock extracts.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.365-373
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• 1997

In this paper, a new method of the 3D(dimensional) image reconstruction is proposed to build up the 3D image from 2D images using digital image processing techniques and computer graphics. First, the new feature extraction algorithm that doesn't need various input parameters and is not affected by threshold is adopted This new algorithm extracts feature points by eliminating some undesirable points on the ground of the connectivity. Second, as the cast function to reconstruct surfaces using extracted feature points, the minimum distance measure between two plane images has been adopted According to this measure, the surface formation algorithm doesn't need complex calculation and takes the form of triangle or trapezoid To investigate usefulness, this approach has been applied to a head CT image and compared with other methods. Experimental comparisons show that the suggested algorithm yields better performance on feature extraction than others. In contrast with the other methods, the complex calculation for surface formation in the proposed algorithm is not necessary.

• Mycobiology
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• v.45 no.4
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• pp.434-437
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• 2017

An improved method for extracting high quality and quantity RNA from a jelly mushroom and a dimorphic fungus-Tremella fuciformis which is especially rich in polysaccharides, is described. RNA was extracted from T. fuciformis mycelium M1332 and its parental monokaryotic yeast-like cells Y13 and Y32. The A260/280 and A260/230 ratios were both approximately 2, and the RNA integrity number was larger than 8.9. The yields of RNA were between 108 and $213{\mu}g/g$ fresh wt. Downstream molecular applications including reverse transcriptional PCR and quantitative real-time PCR were also performed. This protocol is reliable and may be widely applicable for total RNA extraction from other jelly mushrooms or filamentous fungi rich in polysaccharides.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.348-354
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• 2007

Extraction characteristics of ginger (Zingiber officinale) and the functional properties of the corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 38.83% was obtained under the specific extraction conditions, such as microwave power of 126.68 W, ethanol concentration of 53.39% and extraction time of 8.15 min. The maximum electron donating ability (EDA) was found as 77.92% at the conditions of 58.25 W microwave power, 91.87% ethanol concentration and 5.54 min extraction time. The maximum inhibitory effect on tyrosinase was 79.39% at 106.08 W, 2.06% and 5.61 min. The maximum polyphenol content was 105.59% under the extraction conditions of 81.82 W, 99.52% and 4.06 min. Based on superimposition of four dimensional RSM with respect to extraction yield and electron donating ability and polyphenol content obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $0{\sim}80\;W$, ethanol concentration of $0{\sim}40%$ and extraction time of $3{\sim}7$ min.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.281-285
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• 2015

An oleaginous fungus was isolated from soil and identified as Mortierella sp. (M-12) for producing arachidonic acid (AA). Cell disruption methods, extraction methods, and particle sizes of freeze-dried biomass were tested to achieve maximum extraction of total lipids and AA. M-12 grown in glucose yeast media at $25^{\circ}C$ for 7 days contained 35.5% total lipid, and 47% of the total lipid was AA. Lipid extraction yield from wet biomass was shown to be similar to that in a dry state. Maximum lipid extraction was achieved using a mixture of chloroform and methanol (2:1) as an extraction solvent. Different mechanical cell disruption methods did not affect lipid extraction yields. The smaller the particle size of the biomass, the better the lipid extraction yield was observed. Particle size of biomass was shown to more strongly affect lipid extraction than extraction time. The highest AA content was observed in the class of neutral lipids.