• Journal of Life Science
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• v.30 no.6
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• pp.555-562
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• 2020

This study analyzed the total polyphenol (TP), total flavonoid (TF), and protein content, the Absorbance at 400 nm (A400), and the antioxidant and hemolytic activities of 150 Korean honey products, including 41 chestnut (CH), 42 acacia (AH), 62 multi-floral (MH), and five Styrax japonica (TH) varieties. Our results showed that the components and antioxidant activities of honey are dependent on botanical origin rather than farming area or farmer. CH showed the highest levels of TP (88.6±29.8 mg/100 g) and TF (1.20±0.82 mg/100 g), whereas TH had the highest protein (21.5±5.1 mg/100 g). A400 was the highest in CH (0.161±0.044). All of the honey products exhibited negligible hemolytic activity against human red blood cells up to 1 mg/ml. Potent radical scavenging activities for 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azobis(3-ethylbenzothiazoline-6- sulfonate) (ABTS), nitrite and reducing power were also observed in CH. Correlation coefficients (CCs) between analysis parameters were calculated and the highest was identified between TP and ABTS scavenging activity (0.726). The CCs between A400 and TP and A400 and ABTS scavenging activity were 0.644 and 0.661, respectively, suggesting that A400 could be used as a quality indicator for the polyphenol content and antioxidant activity of particular honeys. Future research on polyphenol by flower origin and the identification of compounds for A400 is necessary.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.371-380
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• 2017

In this study, 17 kinds of polyphenols and 5 kinds of anthocyanins were analyzed to compare the contents of polyphenols and anthocyanins in 76 colored agricultural products. A total of 17 polyphenols were analyzed simultaneously by 9 phenolic acids (gallic acid, protocatechuic acid, chlorogenic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, t-ferulic acid, t-cinnamic acid) and 8 flavonoids ((+)catechin, syringic aldehyde, rutin, epicatechin gallate, naringin, luteolin, naringenin, kaempferol) and 5 anthocyanins (delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-arabinoside) were simultaneously analyzed. The total content of 17 polyphenols was determined as seoritae $255.1{\pm}7.5{\mu}g/g$, seomoktae $275.8{\pm}5.3{\mu}g/g$, black rice $78.5{\pm}4.6{\mu}g/g$, black sesame $75.8{\pm}3.2{\mu}g/g$, blueberry $143.3{\pm}5.5{\mu}g/g$, aronia $195.2{\pm}4.9{\mu}g/g$ and blackcurrent $131.6{\pm}3.2{\mu}g/g$, the highest content was found in the order of seomoktae > seoritae > aronia > blueberry > blackcurrant > black rice > black sesame. The total content of 5 anthocyanins was determined as seoritae $82.4{\pm}17.2{\mu}g/g$, seomoktae $95.2{\pm}6.1{\mu}g/g$, black rice $74.1{\pm}9.7{\mu}g/g$, black sesame were not detected, blueberry $110.8{\pm}1.9{\mu}g/g$, aronia $218.9{\pm}6.1{\mu}g/g$ and blackcurrent $209.7{\pm}4.0{\mu}g/g$, the highest content was found in the order of aronia > blackcurrant > blueberry > seomoktae > seoritae > black rice. These results indicated that seomoktae and aronia possessed the high level of functional components and further study will be needed to develop high value-added foods based on the colored agricultural products.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.486-491
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• 2019

Phenolic compounds and antioxidant activities of ethanol extracts from barley sprouts were evaluated in this study. Barley sprouts were extracted using water and ethanol in various concentration (25, 50, and 75%) using reflux extraction methods. Ultra performance liquid chromatography (UPLC) analysis showed that barley sprouts are mainly composed of rutin, gallic acid, ferulic acid, and ${\rho}$-coumaric acid. The 75% ethanol extracts had higher total polyphenol contents ($44.01{\pm}1.32mg/g$) and total flavonoid contents ($102.96{\pm}2.49mg/g$). 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity ($EC_{50}$ value: $1.65{\pm}0.02mg/mL$) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activity ($EC_{50}$ value: $1.67{\pm}0.02mg/mL$) of the 75% ethanol extracts of barley sprouts were found to be the most effective. The 75% ethanol extracts of barley sprouts exhibited a strong reducing activity and ferric reducing antioxidant activity. As a result, the 75% ethanol extracts of barley sprouts showed stronger antioxidant activity than other extracts.

• Food Science and Preservation
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• v.20 no.5
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• pp.608-613
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• 2013

The physicochemical characteristics and antioxidant capacities of 15 red wines (Cabernet Sauvignon) from the US (5) and Chile (10) were investigated. The contents of soluble solid, reducing sugar, titratable acidity, and $SO_2$ were measured. Antioxidant capacities were examined by DPPH, ORAC assay, and total phenolic contents. In addition, polyphenols composition were analyzed by HPLC. The contents of soluble solid, reducing sugar, and acidities were 7.03~8.6 $^{\circ}Brix$, 2.7~6.7 g/L, and 0.7~0.8%, respectively, and showed no differences between wines from the two countries (p<0.05). The $SO_2$ content of Chile wines was 50% higher than that of US wines (p<0.05). Antioxidant activities by DPPH assay ranged 5.58~9.80 mM and 6.77~9.48 mM in the US and Chile wines, respectively. The ORAC values of the US and Chile wines ranged 2.17~18.08 mM and 4.55~33.77 mM, respectively. The total phenolic content ranged from 1,315 to 2,651 mg/L among the US red wines, and from 1,653 to 2,493 mg/L among Chile red wines. Gallic acid, catechin, syringic acid, p-coumaric acid, quercetin, and kaempferol were identified by HPLC. The polyphenol contents of the Chile red wines were higher than those of the US red wines(p<0.05). There were no differences in the physicochemical characteristics and the antioxidant capacities of the wines from US and Chile, but only in their $SO_2$ and polyphenol contents (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.723-727
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• 2003

The antioxidant activities and their antioxidant compounds of a group of teas obtained in local markets were investigated. A total of 18 teas were tested for their antioxidant activities based on their ability to scavenge ABTS (2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) cation radical and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. The former was expressed as mg of ascorbic acid equivalents per 1 tea bag (L-ascorbic acid equivalent antioxidant capacity, AEAC) and the latter was expressed as percentage of electron donating activity (EDA%). A good correlation of AEAC and EDA was observed between the two methods. The concentrations of total polyphenolics and flavonoids in tea extracts were measured by spectrophotometric methods. Total ascorbic acid was determined via the 2,6-dicholoroindophenol titrimetric method. According to the AEAC value and EDA, black tea, brown rice green tea, green tea, herb tea and malva tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of polyphenolic compounds were observed in black tea, green tea and herb tea. Overall, six teas out of 18 teas tested in the study showed better antioxidant activities and higher amounts of total polyphenolic compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.942-948
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• 2011

The physiological activities of extracts from the leaf, stem, and fruit of Cudrania tricuspidata were investigated. The electron-donating ability (EDA) of the 70% (v/v) ethanolic extract of stem was 90.20%; this was the highest value of all the extracts tested and higher than the L-ascorbate solutions. The total polyphenol contents were the highest in the leaf extracts under all extraction conditions. Especially, 70% (v/v) methanolic extract of leaf contained the highest total polyphenol content of 224.48 mg%. SOD-like activity showed the highest activity in water extract of leaf at 64.53%. Tyrosinase-inhibitory activities were the most effective in all extracts of fruit. ACE inhibitory activities were the highest in water extract of fruit. Nitrite-scavenging abilities under acidic conditions (pH 1.2 and pH 3.0) were the most effective in all the extracts. The results of this study will be useful for understanding the physiological activities of Cudrania tricuspidata extracts.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.110-119
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• 2024

This study was conducted to provide information on the possibility of using Rhododendron micranthum as resource plant. Through polyphenol profiling of R. micranthum shoot extract, useful components were selected and the content of useful components and antioxidant activity by extraction solvent were compared. As a result, 37 polyphenol compounds were identified in R. micranthum shoot extract through LC-ESI-MS analysis. Contents by extraction solvent were compared of chlorogenic acid, astragalin, myricetin, and afzelin. Chlorogenic acid was highest at 6.57±0.12 mg/g in the ethanol extract, astragalin was 2.29±0.02 mg/g in the ethanol extract, myricetin was 4.77±0.06 and 4.52±0.27 mg/g in the methanol, ethanol extracts, and afzelin was highest at 0.10±0.01 mg/g in the methanol extract. Total polyphenol content of the R. micranthum shoot extract according to the extraction solvent was highest in the ethanol extract at 80.01±2.36 mg/g, and total flavonoid content was also highest in the ethanol extract at 78.08±3.44 mg/g. The IC₅₀ value of DPPH radical scavenging activity according to the extraction solvent of R. micranthum shoot was lowest in methanol extract at 943.57±10.68 mg/L, and the IC₅₀ value of ABTS radical scavenging activity was also lowest in methanol extract at 641.60±7.58 mg/L.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1309-1314
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• 2006

This study analyzed the contents of vitamin C, polyphenol compounds, and evaluated the inhibitory activities against xanthine oxidase and tyrosinase of Lepista nuda extract prepared by the reflux and microwave-assisted methods. The vitamin C content of the fresh L. nude was $9.92{\pm}0.02$ mg/100 g. The content of phenolic compounds in the fresh L. nuda was $1.87{\pm}0.02\;mg/g$. The ethanol extracts prepared by reflux method and microwave-assisted method showed the highest phenol contents of $12.06{\pm}0.12\;mg/g\;and\;11.84{\pm}0.17\;mg/g$, respectively. The inhibitory rates on xanthine oxidase and tyrosinase of ethanol extracts prepared by the microwave assisted method showed the highest value of 99.78% and 30.30% at the concentration of $3,000{\mu}g/mL$. The inhibitory activities on xanthine oxidase and tyrosinase were increased depending on the extract concentration.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.549-556
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• 2005

Estrogenic and antioxidant activities of ethanol extracts of 45 edible and medicinal plants were evaluated by ${\beta}-galactosidase$ assay, and DPPH radical scavenging assay, and TBARS inhibition rate, respectively. Total polyphenol contents were in the range of 8.6 (Panax notoginseng Buck F.H. Chen.)-594.7 (Amomum globosum Loureiro) mg/g. Direct correlation between the DPPH radical scavenging activity and polyphenol content $(r^2=0.61)$ was established through simple regression analysis, whereas no correlation was observed between TBARS inhibition rate or ${\beta}-galactosidase$ activity and polyphenol content. Among medicinal plants screened, Glycyrrhiza glabra L. and Rheum undulatum L. showed strong antioxidant and estrogenic activities. Results of this study could be used as fundamental data for selecting potential phytoestrogen candidates.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.897-905
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• 2014

The foliage of sweet potato [Impomoea batatas (L.) Lam] is an excellent source of food material due to the functional components of polyphenol and carotenoid. In this study, the lightness (L-value), polyphenol contents, and DPPH radical scavenging activity of the foliage of Shinwhangmi, Hayanmi and Suioh cultivars harvested after different cultivation periods (60, 90 and 120 days after planting) and according to tip locations (1st~5th, 6th~10th, 11th~15th tips) were investigated. As a result, Shinwhangmi showed a lower lightness value (60 days after planting and 1st~5th tips). The longer the cultivation periods and the closer the tips, the higher the contents of polyphenol and DPPH radical scavenging activity were in lyophilized foliage of Shinwhangmi, Hayanmi and Suioh. In the 1st~10th tip of Shinwhangmi, Hayanmi and Suioh cultivated for 90 days and dried by 2 step hot-air (1st: $70^{\circ}C$ for 8 hr, 2nd: $80^{\circ}C$ for 4 hr), the polyphenol and ${\beta}$-carotenoid contents were 5.0, 3.9 and 4.0 mg/g and 75.6, 71.6 and 63.1 mg/g, respectively. The DPPH radical scavenging activities and ABTS radical scavenging activities ($EC_{50}$) were 0.29, 0.36 and 0.33 mg and 0.12, 0.15 and 0.11 mg, respectively. These antioxidative activities were over two times stronger than spinach.