• 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.

• Herbal Formula Science
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• v.18 no.2
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• pp.125-134
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• 2010

Objectives : This study was performed to compare the differences between decoctions extracted by different extraction conditions. Methods : Two different decoctions were prepared with pressured or non-pressured extraction conditions for 60, 120 and 180min. The yields of extracts, sugar contents, hydrogen ion concentrations(pH), the contents of reference compounds and individual preferences on Ssanghwa-tang(Shuanghe-tang) were investigated. Results : As extraction time increased, individual preferences for decoctions by pressured extraction tended to increase more than those by non-pressured extraction, and the yields and sugar contents of both decoctions showed the tendency of increase. The pH values of decoctions in pressured conditions were lower than those in non-pressured conditions in all extraction times and both extraction conditions showed decreasing pH values according to increase of extraction times. Of the reference compounds, paeoniflorin showed higher contents in non-pressured conditions than in pressured conditions and the contents of cinnamaldehyde were always lower in non-pressured conditions than in pressured conditions at all time. Conclusions : The decoctions of Ssanghwa-tang(Shuanghe-tang) extracted by pressured or non-pressured extraction for 60, 120, 180min exhibited different individual preferences, yields of extracts, sugar contents, pH, reference compounds contents.

• Journal of Pharmacopuncture
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• v.21 no.2
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• pp.48-60
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• 2018

Objective: The aim of this study is to optimize the extraction of beneficial substance from Cudrania tricuspidata leaves grown at Jirisan Mountain in South Korea by three different solvents depending on extraction time and at different temperature. Methods: The total phenolic contents were determined by the method reported by $S{\acute{a}}nchez$-Moreno et al. The total flavonoid contents were analyzed by Slinkard and Singleton. The DPPH radical scavenging activity was determined according to the method reported by Blois Results: The extraction yield for each solvent is 9.05-14.1%, 2.17-5.67%, and 2.3-3.9% for D.W., ethanol, and hexane, respectively. The overall results were maximized for the extract obtained with D.W. for 5 min at $100^{\circ}C$. The average phenol contents were 77.11, 45.64, and 0.343 mg/g at $100^{\circ}C$ in water, $78^{\circ}C$ in ethanol, and $68^{\circ}C$ in hexane, respectively. The flavonoid contents were the highest in the materials extracted with D.W., and were increased with increasing temperature, regardless of the extraction solvents, whether water (green), polar organic ethanol, or nonpolar organic hexane. In the ethanol extract, the flavonoid contents are increased gradually from 5.66 mg/g to 7.73 mg/g. The total flavonoid contents were proportional to the concentrations of the water extracts, ranging from 4.14 mg/g to 48.89 mg/g. The antioxidative activities of the water-extracted compounds are generally increased with increasing temperature from 42.5% to 85.5%. Those of the hexane extracts are increased slowly from 3.79% to 8.8%, while those of ethanol extracts are increased from 29.8% to 47.4%. Conclusion: The extraction yields were dependent upon solvents for extraction as well as extraction time and the temperature. The optimal extraction time was 5 min and the extraction yields were increased with increasing temperature excepted hexane. Of the three tested extraction solvents, the greenest solvent of water shows excellent results, suggesting that water is among the most effective solvents for natural sample extractions for general medicinal, pharmaceutical, and food applications.

• Herbal Formula Science
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• v.19 no.1
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• pp.175-182
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• 2011

Objectives : This study was performed to compare the differences between decoctions extracted by different extraction method and extraction time. Methods : Decoctions were prepared with pressed or non-pressed extraction conditions for 60, 120 and 180min. The yields of extracts, sugar contents, hydrogen ion concentrations(pH), the contents of reference compounds in Yukmijihwang-tang(Liuweidihuang-tang) were investigated. Results : The yields and the dissolved solid content containing sugar content of decoctions were more in pressed extraction method than unpressed extraction method, and they tended to be increased as extraction time increased. The pH values of decoctions methods did not show significant differences between pressed and unpressed extraction methods or extraction times. Most of reference compounds showed higher contents in pressed extraction method than unpressed extraction method and their contents were augmented according to increase of extraction time. The content of paeonol was decreased when extracted in more than 120min with pressed extraction method and tended to be decreased as extraction time increased in unpressed extraction method. Conclusions : The pressed extraction with long extraction time could be useful for decoction of Yukmijihwang-tang(Liuweidihuang-tang). However, another ingredients possible to decrease in such condition need to be considered to determine suitable extraction condition.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.97-104
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• 2013

The objective of this study is to investigate the optimal condition for macerating enzymatic extraction process that leads to the highest yield and the largest extracted amount of bio-active contents from Rubus coreanus Miq. fruit. The optimal extraction conditions were found as the following: The initial amount of the water added to the fruit was 20 ~ 30% by weight. The mixing ratio used for the macerating enzyme was 4 : 1 : 2 (w : w : w) for cellulase:pectinase:amylogucosidase, and the amount of the macerating enzyme added was 2% by weight. The extraction process was done at a temperature of $45{\sim}50^{\circ}C$ for 10 hours. The extraction yields on Rubus coreanus Miq. fruit by macerating enzymatic extraction process was increased by 84.3% compared to that of hot-water extraction process. The amounts of organic acids and vitamin found in the extract were also higher. The amount of polyphenol and anthocyanin contents in the extract were 185% and 257% of those from hot-water extraction, respectively. These results suggest that macerating enzymatic extraction is an effective method to boost extraction yield and to increase the amount of extraction of bio-active contents from Rubus coreanus Miq. fruit.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.650-660
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• 2019

The purpose of this study is to verify the effect of the contents of tooth extraction education using VR(virtual reality) on knowledge, performance and satisfaction of practicing teeth. To accomplish this purpose, we divided 72 dental students into the two groups: The experimental group 30 dental students using VR based tooth extraction training contents. And the control group consisted of 42 participants. As a first result for the study, The experimental group using VR tooth extraction content and control group receiving the training using the tooth model based content showed no statistically significant difference in tooth extraction knowledge. Second, in the case of performance of tooth extraction (before tooth extraction-tooth extraction-after tooth extraction-finishing), the training group using VR tooth extraction contents was higher than the control group. Third, The satisfaction rate of the practice group using VR tooth extraction education contents was higher than in the control group. Therefore, it can be seen that the practical training using the VR applied tooth extraction contents improves the performance of the tooth extraction and the satisfaction of the practice more than the existing practice method.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.104-110
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• 2021

This study was conducted to confirm the change in the contents of the ingredients according to the extraction method of nipa palm. The contents were analyzed by extraction according to the ethanol ratio, extraction time, and extraction temperature. The contents of polyphenols and flavonoids according to the ratio of the extraction solvent were the highest at 36.91 and 27.62 mg/g, respectively, when extracted with 50% ethanol. Polyphenols and flavonoids according to extraction temperature and extraction time showed the highest content of 40.83 and 37.63 mg/g, respectively, when extracted for 6 hours at 60℃. The contents of the major component of nipa palm according to the ethanol ratio were 2.08 mg/g in 70% ethanol for 5-O-caffeoylshikimic acid, 0.10 mg/g for 4-hydroxybenzoic acid in 30% ethanol, and 0.12 mg/g for 3,4- hydroxybenzoic acid in 50% ethanol. It is expected that it can be used as basic research data when developing natural materials such as food and cosmetics through the change in the contents of the ingredients contained in nipa palm according to the extraction methods.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.85-92
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• 1985

Extraction efficienties of volatile organic acids in tobacco leaves according to several extraction methods were investigated and contents of volatile organic acids in 16 kinds of tobacco leaf varieties were compared. Extraction efficiency according to simultaneous distillation and extraction was 5 to 10 times higher than that according to solvent extraction, steam distillation, essential oil extraction or continuous extraction and distillation. Total contents of volatile organic acids were 1.62 to 12.94mg per l00g of sample in aromatic tobacco varieties,0.12 to 2.08mg in flue-cured tobacco leaves, and trace in burleys. Among the Korean aromatic tobacco varieties, total contents of volatile organic acids in ST374-3 were the highest, 4.66mg per l00g of sample, and those in Sohyang and Hyangcho were low, 1.69mg and 1.62mg, respectively. Among flue-cured tobacco varieties, those in NC2326 were the highest, 2.08mg per 100g of sample, but those in the other varieties were not more than 0.80mg per 1 00g of sample. Total contents of volatile organic acids in acidic hydrolysis with 0.1 M tartaric acid were higher than in non-acidic condition in all kinds of tobacco varieties.

• 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 Life Science
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• v.10 no.2
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• pp.202-209
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• 2000

The factors affecting chemical composition of green tea (Camellia sinensis L.) during extraction process were temperatures and times. The optimum extraction conditions were measured in relation to the changes of chemical compositions from water extracts of green tea (Camellia sinensis L.) under different extraction temperatures (50, 70, 9$0^{\circ}C$) and extraction times (1, 3, 5 minute). The change of color intensity during browning reaction, flavonoid components, contents of total phenols and hydrogen donating activity (reducing activity for $\alpha$, $\alpha$'-diphenyl-$\beta$ -picryhydrazyl) of water extracts form green tea increased as extraction temperatures increased from 50 to 9$0^{\circ}C$ and extraction times prolonged from 1 to 5 min. The contents of important free sugars such as sucrose and glucose slightly increased as the extraction time was prolonged, while little difference in the content of fructose with the prolonged extraction time. Catechins contents extracted from the commercial steamed green tea were increased at higher temperature and longer extraction time. Epigallocatechin (EGC) extracted from 9$0^{\circ}C$ (extraction time 5 min). presented 99.9 mg/g in highest composition of catechin followed by epigallocatechin gallate (EGCg), epicatechin (EC), epicatechin gallate (ECg). The content of vitamin C extracted from green tea was increased about 2 times as the extraction temperature increased from 50 to 9$0^{\circ}C$ and as the extraction time increased from 1 to 5 min. with exception at 9$0^{\circ}C$(extraction time:5 min) which showed less vitamin C content than 7$0^{\circ}C$(extraction time : 3 min) probably due to possible destruction of vitamin C by high temperature.