• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.190-194
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• 2005

This study was conducted to investigate the changes in contents of total flavonoid and total polyphenol of three leafy vegetables, spinach(Spinacia oleracea L.), chard(Beta vulgaris L.), whorled mallow(Malva verticillata L.) by various blanching times. Total flavonoid and total polyphenol contents of spinach were 21.01 and 25.58 mg/g, those of chard were 26.02 and 35.14 mg/g, and those of whorled mallow were 16.80 and 19.94 mg/g, respectively. Total flavonoid and total polyphenol contents of chard were the highest among the leafy vegetables. Total flavonoid and total polyphenol contents of leafy vegetables were decreased according to blanching time. Especially, total flavonoid content of chard showed significant loss of $15-30\%$ by blanching time. Total polyphenol content of whorled mallow showed loss of $37-39\%$, but the decrease was not significant.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.946-951
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• 2016

In this study, Ilex serrata Thunb was extracted with 70% methanol and concentrated under reduced pressure to measure its total polyphenol contents; furthermore, we examined the effect of electron donating ability of the various extracts. The extract was fractionated using different solvents such as methylene chloride, ethyl acetate, and methanol to investigate total polyphenol contents and electron donating abilities. The total polyphenol contents were $1,058.59{\pm}85.85{\mu}g\;GAE/mL$ in 70% methanol, $297.29{\pm}29.43{\mu}g\;GAE/mL$ in methylene chloride, $313.28{\pm}9.22{\mu}g\;GAE/mL$ in ethyl acetate, and $837.82{\pm}31.16{\mu}g\;GAE/mL$ in methanol. The total polyphenol contents showed significant differences (p<0.05) between the solvents. The electron donating abilities were $72.93{\pm}0.29%$ for 70% methanol extract, $14.02{\pm}2.01%$ for methylene chloride, $24.05{\pm}1.75%$ for ethyl acetate, and $84.08{\pm}1.95%$ for methanol. The electron donating abilities were significantly different (p<0.05) between the solvents. The two portions of Ilex serrata Thunb extracts obtained from methanol showed significantly relevant results in the total polyphenol contents and electron donating ability, which was higher than the original extract.

• Korean Journal of Oriental Medicine
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• v.16 no.3
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• pp.175-178
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• 2010

The aim of this study is to compare antioxidant activity and total polyphenol contents between before and after fermentation of Ssanghwa-tang according to solvent partition. Ssanghwa-tang was fermented with Lactobacilus fermentum. Ssanghwa-tang and the fermented Ssanghwa-tang were fractioned by solvent partition with ethyl acetate, butanol and water. The Ssanghwa-tangs and their solvent fractions were evaluated for total polyphenol contents and DPPH radical scavenging activity. The antioxidant activity as well as the total polyphenol contents were highest in each ethyl acetate fraction and significantly (p<0.05) increased after fermentation.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.975-980
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• 2009

In this study we evaluated polyphenol contents, phytate contents, and antioxidant activities (DPPH radical and hydroxyl radical scavenging activity) in several soybean cultivars. The polyphenol contents of the cultivars ranged from 0.0446 mg/g to 0.0652 mg/g, with the highest level found in the WS82 cultivar, whereas and the lowest in Duyukong. The phytate content of the WS2906 cultivar was the highest at 22.28 mg/g whereas Duyukong showed the lowest level. $IC_50$ values (concentration of soybean extract exerting 50% scavenging of radicals) for DPPH radical and hydroxyl radical scavenging activity showed the highest in WS82. A positive correlation between DPPH radical scavenging activity and polyphenol contents was observed in the soybean cultivars, whereas not significant relationship between antioxidant activity and phytate content was found.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.527-538
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• 2023

The aim of this study was to investigate the antioxidant effects of O. robusta stem extract (ORE) and to determine the total polyphenol and flavonoid contents. Free radical scavenging properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and ·OH (hydroxyl radical) scavenging assays. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods, respectively. Active compounds of ORE were determined using high-performance liquid chromatography (HPLC). The results of the study showed that ORE exhibited DPPH, ABTS, and ·OH radical scavenging activities in a dose-dependent manner. Especially, 1,000 ㎍/mL of ORE showed the strongest radical scavenging properties against DPPH, ABTS, and ·OH. ORE contained total polyphenol content of 57.4 mg GAE/g and total flavonoid content of 5.4 mg QE/g, which may contribute to their antioxidant effects. As a result of HPLC, the contents of active compounds in ORE, dihydrokaempferol (0.65 ㎍/mL), and 3-O-methylquercetin (1.10 ㎍/mL) were confirmed. In conclusion, ORE may be useful as a functional material with antioxidant properties.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Natural Product Sciences
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• v.24 no.4
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• pp.247-252
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• 2018

Halophytes are expected to possess abundant secondary metabolites and various biological activities because of habitat in extreme environments. In this study, we collected 14 halophytes (Asparagus oligoclonos, Calystegia soldanella, Carex pumila, Chenopodium glaucum, Elymus mollis, Glehnia littoralis, Limonium tetragonum, Messerschmidia sibirica, Rosa rugosa, Salsola komarovii, Spergularia marina, Suaeda glauca, Suaeda maritima, and Vitex rotundifolia) native to Korea and compared their total polyphenol contents, antioxidant and anti-inflammatory activities. The total polyphenol contents of R. rugosa (27.28%) and L. tetragonum (13.17%) were significantly higher than those of the other 12 halophytes and L. tetragonum, R. rugosa, and M. sibirica showed significantly greater antioxidant activities than the other 11 halophytes, as determined by DPPH (2,2-diphenyl-1-picrylhydrazyl). A. oligoclonos, E. mollis, and C. pumila showed significantly greater anti-inflammatory activities than the other 11, as determined by NO (Nitric oxide) and $PGE_2$ (Prostaglandin $E_2$) levels. In contrast, these three extracts had normal and low total polyphenol contents among the 14 halophytes. Consequently, the total polyphenol content in the 14 studied halophytes appeared to be related to antioxidant, but not anti-inflammatory activity levels.

• The Korean Journal of Food And Nutrition
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• v.33 no.2
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• pp.210-214
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• 2020

In this study, polyphenol and flavonoid contents were measured, and DPPH, OH, H₂O₂ radical scavenging activity, and the α-amylase inhibitory activity were measured to study the antioxidant activity of 70% ethanol extract from Morinda citrifolia L. The polyphenol and flavonoid contents of noni 70% ethanol extract were 29.52 GAE/g and 12.48 CE/g, respectively. Also, the IC₅₀ values of DPPH, hydroxyl radical, and hydrogen peroxide scavenging activity of 70% ethanol extract from noni were 18.70 mg/mL, 26.45 mg/mL, and 35.67 mg/mL, respectively. Measurement of the α-amylase inhibitory activity of 70% ethanol extract from noni showed 45% inhibitory activity at 10 mg/mL.

• Journal of the Korean Society of Food Culture
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• v.22 no.3
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• pp.336-341
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• 2007

Antioxidant activity of Astragalus membranaceus, Polygonatum stenophyllum, Angelica gigas, Acanthopanax sessiliflorus and Angelica pubescens extracts cultivated in Jecheon prepared with different solvents were determined by 1,1-diphenyl-2-picrylhydrzyl(DPPH) radical scarvenging ability and thiocyanate method . The highest hydroxy radical scarvenging activity was shown in Acanthopanax sessiliflorus, while the lowest was in Polygonatum stenophyllum. Angelica gigas showed strong antioxidant activity by thiocyanate method. Methanol extracts and water extracts showed higher antioxidant activities than ethanol extracts. Angelica pubescens showed the highest polyphenol contents and Acanthopanax sessiliflorus showed the highest flavonoid contents. Direct correlation between the hydroxy radical scavenging activity and polyphenol contents or flavonoid contents was established by simple regression(r>0.8) in each solvent extracts. Among medicinal plants cultivated in Jecheon, Acanthopanax sessiliflorus and Angelica pubescens showed strong antioxidant activities. These results suggest that methanol or water extracts of several medicinal plant cultivated in Jecheon could be used as natural antioxidants.

• The Korean Journal of Food And Nutrition
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• v.34 no.5
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• pp.537-544
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• 2021

In this study, antioxidative activities of Jeolpyun containing Smilacis chinae R. extract powder (2%, 4%, 6%, 8%) were evaluated using total polyphenol contents, electron donating ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and decomposing ability of hydrogen peroxide. In chromaticity analysis, the brightness significantly decreased with increasing Smilacis chinae R. extract powder content. Jeolpyun containing 6% Smilacis chinae R. extract powder revealed the highest value (9.67±0.603) for the redness and 2% Smilacis chinae R. extract powder was the highest value (14.20±0.917) for the yellowness. Total polyphenol contents of Jeolpyun containing 8% Smilacis chinae R. extract powder were the highest content of 17,320±390.38 ㎍ gallic acid equivalent/mL (GAE/mL). Total polyphenol contents were significant relation at p<0.05. Electron donating ability for Jeolpyun containing 8% Smilacis chinae R. extract powder revealed the highest electron donating ability (74.24±0.827%). Electron donating abilities revealed significant difference (p<0.05). Jeolpyun containing 6% Smilacis chinae R. extract powder revealed the most hydrogen peroxide decomposing ability (-3.38±1.44) and hydrogen peroxide decomposing ability revealed significant difference (p<0.05).