• 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.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.667-671
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• 2003

The total phenolic and flavonoid contents of Lentinus edodes extracts were determinated by spectrophotometrical .method, and antihepatotoxic activity was detected on glutathione S-Transferases(GST). The total phenolic contents was highest water extract than solvent(ethanol, methanol) extracts, but flavonoid content was appear on opposite. GST activity was the highest appears in water extract. This fact verified of anticancer effect indirectly of Lentinus edodes.

• 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.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.268-273
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• 2005

Changes in contents of phytochemical compounds (${\beta}$-carotene, ascorbic acid, chlorophylls, total flavonoid, total polyphenol) and hazardous factors (microbial counts, nitrate) of spinach (Spinacia oleracia L.) were investigated by conventional and microwave blanching methods. ${\beta}$-Carotene and chlorophylls contents of spinach were significantly increased by blanching, with conventional blanching resulting in higher contents than microwave blanching. In contrast, contents of ascorbic acid, total flavonoid, and total polyphenol of blanched spinach decreased, with microwave blanching resulting in higher ascorbic acid, total flavonoid, and total polyphenol contents than conventional blanching. Total plate count and total coliforms of blanched spinach significantly decreased, with conventional blanching showing less than 20-25% of microwave blanching. Nitrate content of blanched spinach also showed decreasing pattern, with decrease due to microwave blanching being lower, although not significantly, than that of conventional blanching.

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.331-338
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• 2020

Background: The aim of this study was to analyze the total phenol and total flavonoid contents and antioxidant activity of steam-treated leaves and rhizomes of Polygonatum sibiricum Redoute. In addition, we aimed to confirm their potential use as cosmetic materials by investigating their anti-aging and skin-whitening activity. Methods and Results: The leaves and rhizomes of P. sibiricum were treated with steam at different temperatures for different durations, and the antioxidant activity (DPPH and ABTS radical scavenging activity) and total phenol and total flavonoid contents of each sample were tested. The steam temperature and treatment duration siginificantly affected the antioxidant activity and, total phenol and total flavonoid content of the leaves and rhizome of P. sibiricum. Treating the P. sibiricum samples with steam at 120℃ for 12 h, yielded higher total phenol and total flavonoid contents. Comparatively, the samples treated with steam at 120℃ for 12 to 24 h showed significantly higher antioxidant activity. Further, the steamed samples of P. sibiricum demonstrated collagenase and tyrosinase inhibition activity, which indicated their anti-aging and skin-whitening properties. The samples steamed at 120℃ for 12 h, exhibited higher collagenase and tyrosinase inhibition activity. Conclusions: Leaves and rhizomes of P. sibiricum steamed at 120℃ for 12 h, showed highest antioxidant activity and, total phenol and total flavonoid contents than all other samples. Our results indicate the potential of using P. sibiricum as a cosmetic material by confirming its excellent anti-aging and whitening activity.

• 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 Pharmacognosy
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• v.41 no.2
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• pp.130-135
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• 2010

This study was performed to the activity of antioxidant and anti-diabetic from Zanthoxylum schnifolium fruit. The Zanthoxylum schnifolium fruits were extracted with water, 100% methanol, 100% ethanol, 70% methanol and 70% ethanol. The activities of each extracts were measured by antioxidant tests, such as total phenolic contents, total flavonoid contents, hydroxyl radical activity, DPPH radical scavenging activity, reducing power and $\alpha$-glucosidase inhibition activity assay. The water extract represented the highest activity in the antioxidants properties in vitro, including hydroxyl radical activity, DPPH radical scavenging activity, reducing power. Furthermore, water extract also showed significantly high total phenolic contents but the 100% methanol extract showed high total flavonoid contents estimated as $196.48{\mu}g/mg$. The $IC_{50}$ values for $\alpha$-glucosidase inhibition activity of the 100% ethanol and 100% methanol extracts were $275.66{\mu}g/mg$ and $261.44{\mu}g/mg$. Our results indicated that the Zanthoxylum schnifolium fruit expected to be useful as antioxidants.

• 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 $130^{\circ}C$.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.307-312
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• 2003

Antioxidative activities of Methanol and Ethanol extract of branch, bark, leaves, fruits, wood of Hovenia dulcis THUNBER var. koreana Nakai were analyzed for total poly phenol, flavonoid, antioxidant capacity and DPPH free radical scavanging activitiy. The most total polyphenol and flavonoid contents measerd extract from bark and fruits. Extract from fruits and bark show hight on antioxidant capacity and DPPH free radical scavanging activitiy. There was a good correlation between total polyphenol or flavonoid contents and antioxidant activity.