• Journal of the Korean Society of Food Culture
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• v.30 no.2
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• pp.220-226
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• 2015

This study was to conducted to investigate the antioxidative activity of 70% ethanol extracts of kiwi of three different colors (gold, green and red) by measuring DPPH, ABTS radical scavenging activity, tyrosinase inhibitory effect, metal chelating effect, reducing power, and nitrite scavenging activity. Total polyphenol contents were: gold kiwi, 3.09 mg GAE/g, green kiwi 2.71 mg GAE/g, and red kiwi 4.59 mg GAE/g, respectively. Red kiwi showed higher antioxdidant activity than gold and green kiwi. DPPH and ABTS radical scavenging activity, and nitrite scavenging activity of red kiwi exhibited 94.83, 99.57, and 97.88%, respectively, at a concentration of 20 mg/mL, which were equal to those of ascorbic acid (positive control). Metal chelating effect of red kiwi was superior to that of ascorbic acid. Therefore, the availability of red kiwi will be increased in the field of functional material for food additives and value added products.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• Korean Journal of Medicinal Crop Science
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• v.17 no.1
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• pp.15-20
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• 2009

This study was carried out in order to determine the biological activities such as antioxidant activities in nine cultivars of Momordica charantia L. (Korea, China, Japan and Philippine native cultivars). Their antioxidant activities were measured using DPPH free radical scavenging, ABTS cation radical scavenging, and Nitrite scavenging ability. The highest total polyphenol content (16.82 ${\mu}g/m{\ell}$) measured in the native Korea cultivar, and this value was 4.0 ${\mu}g/m{\ell}$ higher than that of the 'Verde Beuhas' cultivar (12.82 ${\mu}g/m{\ell}$). The 'Peacock' cultivar had the highest total flavonoid amount which was 4.38 ${\mu}g/m{\ell}$. The free radical scavenging activity using DPPH method was the highest in the native China cultivar ($RC_{50}$ = 102.6 ${\mu}g/m{\ell}$). ABTS cation radical scavenging activity according to cultivars was significantly higher in 'Peacock'. Nitrite scavenging ability showed the most remarkable effect at the pH 1.2, exhibited to 81.5${\sim}$86.9% by addition of ethanol extract 1${\mu}g/m{\ell}$ from Momordica charantia L. These results suggest that Momordica charantia L. had the potent biological activities, and that their activities exhibited differently depending on cultivars.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.548-556
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• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.363-371
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• 2015

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity ${\beta}$-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.189-194
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• 2007

This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.351-356
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• 2006

In this study, we investigated the effect of adding a 1, 3, or 5% solution of germinated brown rice concentrate (GBRC) to fermented kimchi. During fermentation, the concentration of free amino acids and essential amino acids increased with increasing concentrations of GBRC. In particular, higher levels of free amino acids were associated with a sweet taste compared with controls. The ${\gamma}$-aminobutyric acid (GABA) content of kimchi containing the 5% GBRC solution was 3 times higher than that of controls. The total phenolic compound content (130 mg%) did not change significantly in the control group, but increased in 10 mg% increments as the GBRC concentration rose from 1 to 3 to 5%. 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity and superoxide radical scavenging activity also increased with the GBRC concentration, with maximum activity during the ripe stage with GBRC measured at 79 to 82% compared with controls (30 to 71 %). The nitrite scavenging activity was 10% higher with GBRC compared with controls and was highest when the pH was 1.2. These results showed that the addition of GBRC is effective in improving the function of kimchi.

• 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.

• The Korea Journal of Herbology
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• v.31 no.6
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• pp.45-52
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• 2016

Objectives : This study was performed to investigate the antioxidant activity of water and ethanol extracts from Sasa borealis leaves, stems and roots. Methods : Sasa borealis leaves, stems and roots extract were prepared using water and ethanol. The total polyphenol and total flavonoid contents were analyzed. 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity, SOD like activity, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS), hydroxyl radical scavenging activity, and Nitrite scavenging activity assays were carried out to determine the antioxidant activities. Results : The antioxidant activities of the Sasa borealis appeared higher in ethanol extract than water extracts. Total polyphenol and total flavonoids contents in ethanol extracts of leaves were $24.6mg/m{\ell}$ and $14.3mg/m{\ell}$, respectively, which were much higher than those of any other parts. SOD like activity was 70% ethanol extract of the leaves was highest with 15.68%. Electron donating ability was 70% ethanol extract of the leaves had the highest 59.07%. It exhibited high electron donating ability than BHT(45.68%). Nitrite scavenging activity of 70% ethanol extract was higher than the water extract at pH 2.5 and pH 4.2. Nitrite scavenging activity was 70% ethanol extract of the leaves was the highest 75.2%. Hydroxyl radical scavenging activity was 70% ethanol extract of the leaves was highest with 16.16%, showed very low activity than BHT(61.56%). Conclusions : These results suggest that 70% ethanol extracts from Sasa borealis leaves, exhibited higher antioxidant activities than those of root and stem, and can be potentially used as proper natural antioxidants.

• Advances in Traditional Medicine
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• v.5 no.3
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• pp.209-215
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• 2005

This study was conducted to investigate the efficacy of antioxidative activity and nitrite scavenging ability of each fractions from Phyllostachys bambusoides S. et Z. (P. bambusoides) trunk ethanolic extract using reverse-phase flash chromatography. Among the each fractions, fraction 3 $(H_2O\;:\;MeOH\;=\;1:1)$ showed high DPPH free radical scavenging activity (81.33%) at $80\;{\mu}g/mL$ concentrations and strongly inhibited autooxidation of pyrogallol by superoxide dismutase-like activity (45.8 %) at 0.46 mg/mL concentrations compared with different fractions. The fraction 3 was also increased to 76.62% cell viability against hydrogen peroxide-mediated cytotoxicity. Nitrite scavenging ability was the most remarkable under pH 1.2 condition among various pH regions examined and effectively exhibited to 65.6% by treatment of the fraction 3 with a concentration of 0.2 mg/ml. In general, nitrite scavenging ability decreased with higher pH condition. These results suggest that fraction 3 from P. bambusoides ethanolic extract can be used for bioacitve and functional materials.