• Food Science and Biotechnology
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• v.16 no.5
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• pp.828-831
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• 2007

We evaluated the effects of heat treatment on various properties of onion extracts (Allium cepa). Onion was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid, and free sugar contents, and antioxidant activity were investigated. With increased heating temperatures and exposure times, the total contents of polyphenols and flavonoids, as well as antioxidant activity increased. The highest total polyphenol content (189.80 mg/100g) occurred after heating for 2 hr at $140^{\circ}C$. The highest total flavonoid content (252.51 mg/100g) occurred after heating for 3 hr at $150^{\circ}C$. The antioxidant activity assessed using the DPPH method was highest, at 2.1 mg/mL ($IC_{50}$ value), after heating for 2 hr at $150^{\circ}C$. Correlations between antioxidant activity and the total polyphenol, total flavonoid, and fructose contents were highly significant (all p<0.01). The optimal heating time and temperature were 2 hr and $130^{\circ}C$.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.84-87
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• 2006

Antioxidant activity of Akebia quinata Decne was evaluated. Water extract (0.5 g/50 mL) of flowers and leaves of A. quinata were prepared and total phenol contents and radical scavenging activity of the extracts was determined for antioxidant activity. The total phenol contents of extracts from A. quinata flowers (FAQ) and leaves (LAQ) were $30.05{\mu}M\;and\;20.23{\mu}M$, while the radical scavenging activity of FAQ and LAQ were 60.51 % and 52.97%, respectively. In addition, the effect of FAQ and LAQ extract on DNA damage induced by $H_2O_2$ in human lymphocytes was evaluated by comet assay. The FAQ and LAQ showed strong inhibitory effect against DNA damage induced by $200{\mu}M$ of $H_2O_2$. These results suggest that water extracts of A. quinata Decne flowers and leaves showed significant (p<0.05) antioxidant activity and protective effect against oxidative DNA damage.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.695-703
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• 2016

The purpose of this study was to measure the bioactivity and antioxidant activity of Orostachys japonicus A. Berger. Orostachys japonicus A. Berger have been known to contain functional materials such as kaempferol, hydroquinone, methyl gallate, quercetin, gallic acid etc. To identify the main functional materials of Orostachys japonicus A. Berger, the contents of flavonoid and phenol were measured. We extracted Orostachys japonicus A. Berger powder from four solvents such as chloroform:methanol (CM, 2:1, v/v), distilled water (DW), 70% methanol, 70% ethanol. After that, this study determined tannin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power and reducing power of Orostachys japonicus A. Berger extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of Orostachys japonicus A. Berger extracts was higher in the order of 70% ethanol, 70% methanol, DW and CM (p<0.05). The results showed that antioxidant activity of Orostachys japonicus A. Berger extracts supposed to affect by the total phenol and flavonoid contents.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.414-420
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• 2011

We investigated antioxidant activity and lignan contents by harvesting times to expand use of Schisandra chinensis (Turcz.) Baillon. Total polyphenol and flavonoid contents of seed was higher than those of flesh but there is not much difference in harvesting times. As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, was 13.7~24.2 ${\mu}g/m{\ell}$ in seed thus it showed a high antioxidant activity. Among lignan components, schizandrin content was the highest and followed by gomisin N and gomisin A in all of flesh and seed. Also these components in seed were 4~9 times more contained than those of flesh. All of them were decreased by harvesting times in flesh. But the contents of schizandrin and gomisin N were high in August 3rd and September 15th in seed, respectively. As the results, the seed of S. chinensis had high antioxidant activity and lignan contents so it could be potentially developed as a resource.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.384-392
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• 2007

The primary objective of this study was to determine the effects of a water-distilled extract with 15 kinds of Korean medicinal herb on antioxidant activity, antimicrobial activity against Helicobacter pylori, and lipid metabolism. The water-distilled extract (WE) and fermenting water-distilled extract (FE) of medicinal herbs were utilized in order to make functional beverages. The EDA (electron donating activity), SOD-like ability, and RAE (relative antioxidant efficacy) of WE averaged 24.47, 50.35, and 1.57%, respectively, but the EDA, SOD-like ability, and RAE of FE was retardeded by 12.01, 35.72, and 1.55%, respectively. The antimicrobial activity against Helicobacter pylori of WE averaged 12.84 mm as a diametric clear zone, and was significantly (p<0.05) higher than those measured in the WE and control. Serum triglyceride contents, total serum cholesterol contents, and serum LDL-cholesterol contents of the WE group were significantly (p<0.05) lower than those of the control group. The liver total-cholesterol contents and liver triglycerides of WE group were significantly (p<0.05) lower than those of the control group. The plasma TBARS value of the WE group was significantly (p<0.05) lower than that of the control group. The sensory evaluation, taste, and smell of FE were more desirable than those of WE, but the color of WE was more desirable. According to the above results, the water distilled extracts (WE) of 15 kinds of medicinal herb are supposed to be effective with regard to antioxidant activity and lipid metabolism, but the antimicrobial activity against Helicobacter pylori was increased as the result of fermentation.

• Culinary science and hospitality research
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• v.20 no.5
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• pp.29-33
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• 2014

In this study, we examined the antioxidant activity of the naturaceutical extract in vitro using total phenolic contents, total flavonoids contents, DPPH radical scavenging activity, reducing power assay, and phenolic acid contents. The total phenolic and total flavonoids contents of naturaceutical extract were 5.46 mg/g, 2.21 mg/g, respectively. The DPPH radical scavenging activity of natraceutical extract varied from 18.77 ($200{\mu}g/mL$) to 3.44 ($1,000{\mu}g/mL$). The reducing power of the natraceutical extract absorbance varied from 1.07 (0.78 mg/mL) to 3.44 (12.5 mg/mL), and reducing power of extract presented a concentration-dependent activity increase. The highest amounts of trans-ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, vanillin, vanillic acid, p-hydroxybenzaldehyde, and trans-cinnamic acid were observed in the naturaceutical extract at the levels of 750.79, 619.75, 531.34, 222.04, 219.28, 107.40, and $89.56{\mu}g/g$, respectively. The results imply that this antioxidant effect of the naturaceuticals extract could be harnessed in the management and prevention of degenerative diseases associated with oxidative stress.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.276-287
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• 1986

Chlorella ellipsoidea were cultured in the media containing rifampicin for 7 days. Aliquot cells were taken out after the inoculation and at intervals during cultivation and growth rate of Chlorella cells was measured. In order to investigate the effect of rifampicin on the nucleic acid synthesis, nucleic acid and RNA polymerase were extracted from chloroplast isolated from these cells, and the contents of nucleic acid and activity of enzyme were measured to compared with those of the control. The inhibitory concentration of rifampicin on growth was 80 ppm. The DNA contents in chloroplasts isolated were decreased 60% to compared with control, whole cells were markedly decreased 70% by rifampicin. The contents of base in the RNA were decreased 46% by rifampicin in shole cell, and 77% of base contents were decreased in chloroplast. Rifampicin also inhibited the activity of RNA polymerase, therefore whole cell was decreased 10% of activity and chloroplasts were decreased 42% of activity.

• Journal of Korean Library and Information Science Society
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• v.34 no.4
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• pp.179-202
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• 2003

Reading is a typical representative knowledge and information activities. It is a put of the presents man and by itself Read-learning is the cognitive and social activities of the creating platonic world. However, in the education training of students become a visible problems of read-learning too many. To solve the problems have to pull off a systematical plan in read activities. This aims to purpose the model of the union reading contents management as the method for the read activity based on the problems analysis of read-learning activity. It is reading contents management as the model knowledge cresting processes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.4
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• pp.121-132
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• 2021

This study analyzed the effect of the extracurricular activity management system on user satisfaction. For this purpose, the effects of content, navigation, screen frame, design, interaction, and error handling factors on user satisfaction were analyzed. A survey was conducted on 321 students of K University located in Chungcheongbuk-do, and the research results based on the survey contents are as follows. First, content, navigation, screen frame, interactivity, and error handling, which are major elements of the extracurricular activity management system, showed statistically significant results. Second, interactivity and error handling were found to have the greatest influence on the factors affecting user satisfaction of the extracurricular activity management system. In this study, it was found that the interaction of the whole system including contents is important for continuous improvement of the extracurricular activity management system, and that it has a positive effect on user satisfaction when prompt error handling is possible.

• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.133-140
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• 2019

Antioxidant activities of Ulmus davidiana root and bark extracts were evaluated by various antioxidant tests, including DPPH radical-scavenging, nitric oxide-scavenging, superoxide anion radical-scavenging, and ABTS radical-scavenging assays, and superoxide dismutase (SOD)-like activity and reducing power analysis, along with the determination of total phenolic and flavonoid contents. Both the extracts showed strong antioxidant activities by these testing methods. Ulmus davidiana root extract possessed strong reducing power and nitric oxide-scavenging activity, and high scavenging activities against free radicals including the superoxide anion, and the ABTS and DPPH radicals, but a weaker scavenging activity of SOD. In contrast, the Ulmus davidiana bark extract exhibited a strong SOD-like activity, but all the other activities were weak. It was observed that the total phenolic and flavonoid contents of the Ulmus davidiana root extract were higher than those of the Ulmus davidiana bark extract.