• 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.27 no.1
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• pp.75-81
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• 2012

This study was conducted to investigate the physiological activity of acai berry (Euterpe oleracea Mart.) extracts from three different solvents (water, methanol, and ethanol). We measured total polyphenol and total flavonoid content, DPPH radical scavenging activity, nitrite scavenging activity, metal chelating effect, and reducing power. The extraction yield from water, methanol, and ethanol was 17.10, 9.50, and 37.51%, respectively. The highest total polyphenol content (10.54 mg/100 g) and total flavonoid contents (1.88 mg/100 g) was observed in water extract. DPPH radical scavenging activity was the highest in both water extract (72.03%) and methanol extract (74.79%) at levels of 5 mg/mL, which was similar to that of BHT (78.90%). Water extract yielded the highest metal chelating effect (92.54%) and reducing power (1.09) at levels of 5 mg/mL. Taken together, these findings suggest that extracts of acai berry can be used as functional food materials with antioxidative and nitrite scavenging activities.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.739-744
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• 2012

Cirsium japonicum (Gyonggido (GG), Gangwondo (GW), Jeollanamdo (JN) and Jejudo (JJ)) were investigated for their antioxidative components (total polyphenol and flavonoid contents) and their antioxidant activities (2,2-diphenyl-1-picrylhydrazyl) (DPPH), 2,2'-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP) and reducing power). Analysis of antioxidative components and activities showed significant (p<0.05) differences across samples from various regions (GG, GW, JN, JJ). Amounts of total polyphenol and flavonoid contents were in the order of GG${\geq}$GW>JJ>JN (p<0.05). The results of the antioxidative activity test of Cirsium japonicum showed that GG and GW had higher activities compared to others (p<0.05). Therefore, the results of the antioxidative activity test (DPPH, ABTS, FRAP and reducing power) were correlated with total polyphenol and flavonoid contents values.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.263-270
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• 2016

Background: In this study, microwave extraction was used, which is an effective method to extract useful bioactive substances as it requires low quantities of solvent and short time periods. The aim of this study was to determine the optimal extraction conditions for Agrimonia pilosa Ledeb. Methods and Results: The independent variables were ethanol concentration, microwave power, and extraction time, each of which had five levels. The dependent variables were total polyphenol and total flavonoid content, and DPPH radical scavenging activity. To determine the optimal extraction conditions for bioactive compounds, a response surface methodology was employed. Contour maps were generated from polynomial equations. The optimal conditions were then assumed by superimposing these contour maps. Based on the resulting graph, the optimal microwave extraction conditions for Agrimonia pilosa Ledeb were determined as 42 - 48% ethanol concentration, 240 - 280W microwave power, and 13 - 20 min of extraction time. Conclusions: Ethanol concentration had a significant effect on microwave extraction, in terms of total polyphenol and total flavonoid content, as well as DPPH radical scavenging activity. Microwave power and extraction time influenced the total polyphenol content, but not the total flavonoid content or the DPPH radical scavenging activity.

• KSBB Journal
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• v.31 no.2
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• pp.100-104
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• 2016

Dolsan leaf mustard has various biological functions, including those in the immune system and cancer prevention. It contains high amounts of nutritional and medicinal compounds, which are important for maintaining optimum health. The objective of this study was to determine the total phenolics contents and antioxidant activity in Dolsan leaf mustard pickle (DLMP) during storage. DLMP methanol extracts had the highest total polyphenol and flavonoid contents of $35.56{\pm}0.01GAEmg/g$ and $4.54{\pm}0.03QEmg/g$, respectively. The DPPH and ABTS radical scavenging activities in the DLMP methanol extracts showed the highest activities of 79.4 and 85.36%, respectively. The ferric reducing antioxidant power (FRAP) assay showed 2.24-3.82 mM $FeSO_4$ eq. (p<0.05) in DLMP extracts. Overall, storage at day 14 showed the highest antioxidant activity.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.195-200
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• 2009

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.255-261
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• 2013

The purpose of this study was to examined the antioxidant activities by water and 70% ethanol extract from durian (Durio zibethinus.) seed, sarcocarp and peel. Durian extract were studied for reducing sugar content, polyphenol content, superoxide dismutase (SOD) like activity, electron donating ability, nitrite scavenging ability, flavonoid content, hydroxy radical scavenging activity. Reducing sugar content were increased peel > sarcocarp > seed. Total polyphenol, flavonoid content, DPPH radical scavenging ability and SOD like activity were increased seed > peel > sarcocarp. Total polyphenol content was relatively high as $21.90{\pm}0.50mg/g$ in the ethanol extract of the seed. DPPH radical scavenging ability was relatively high as $62.08{\pm}2.63%$ in the water extract of the seed. Nitrite scavenging ability was no significant difference. Hydroxy radical scavenging activity was increased seed > peel > sarcocarp, was relatively high as $58.27{\pm}1.13%$ in the water extract of the seed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.769-775
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• 2010

The genus Lespedeza belonging to Leguminosae is an annual or perennial herb, which has been used as a Chinese herbal medicine. Antioxidant activity on DPPH ((1,1)-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylenebenzothiazoline-6-sulfonic acid) radicals and the contents of total polyphenol and flavonoid were analyzed with 12 methanol extracts from six Lespedeza genus plants with different plant parts. The highest content of total polyphenol was detected in the leaves of Lespedeza$\times$robusta (194.6 mg GAE/g), while the highest content of total flavonoid existed in the aerial part of Lespedeza thunbergii var. intermedia (47.9 mg QE/g). Generally, the amounts of polyphenol and flavonoid compounds were higher in the leaves than in the stems. The $SC_{50}$ value of DPPH radical scavenging activity ranged from 10.16 to 90.94 ppm, of which the strongest activity was determined in the leaves of L. robusta. Most ABTS radical scavenging activities from the investigated methanol extracts were higher than that of L-ascorbic acid, implying the excellent antioxidant activity. The radical scavenging activity in this study showed high correlation with the amount of total polyphenol rather than that of total flavonoid. These data suggest that the methanol extracts from these Lespedeza spp. could be potential candidates for natural antioxidants.