• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.87-94
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• 2011

Flavonoid contents of common buckwheat (cv. Kitawase) and tartary buckwheat (cv. Hokkai T 8, Hokkai T 9 and Hokkai T 10) were determined by high-performance liquid chromatography (HPLC). Moreover, they were measured at different plant developments such as 10, 18, 20, 22 and 30 days after sowing (DAS) and with plant parts including leaf, stem and flower harvested at 30 DAS. Total flavonoids including chlorogenic acid, four kinds of C-glycosylflavones (orientin, isoorientin, vitexin, isovitexin) and rutin of tartary buckwheats (range of 44.2-54.7, mean 44.2) were found 35% higher than those of common buckwheat (28.9 mg/g dry wt.). Among them, rutin was measured above 80% of total flavonoid contents. The other flavonoids (chlorogenic acid and four kinds of C-glycosylflavones) presented the highest level at 10 DAS and decreased according to plant developments. On the other hand, rutin content of Kitawase presented the highest level (33.6 mg/g dry wt.) at 22 DAS and decreased up to 30 DAS. Rutin content in tartary buckwheat temporarily decreased from 10 to 18 DAS and then reversely increased up to 30 DAS presented the highest level as 'U' curve. In Hokkai T 10, rutin content was found the highest level (53.8 mg/g dry wt.) at 30 DAS. In different plant parts harvested at 30 DAS, rutin content of leaf (range of 42.8-68.0, mean 57.0) was 5.3-fold higher than that of stem (range of 8.0-15.9, 10.8 mg/g dry wt.), regardless of cultivar. Significantly, rutin content (78.7) in the flower of Kitawase was 1.8 times higher than in the leaf and 9.8 times in the stem. Especially, chlorogenic acid content (14.6 mg/g dry wt.) in the flower of Kitawase was 63-fold higher than in the leaf, and 20-fold in the stem.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.7-16
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• 2017

BACKGROUND: Increased value added by rapeseed (Brassica napus) by-product and the development of a usable rapeseed functional tea. METHODS AND RESULTS: To develop a usable rapeseed functional tea, the total flavonoid content in the varieties Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111 was investigated. Effect of three treatments, i.e., drying, leaching, and roasting, on flavonoid contents or flower was tested using multiple processing methods per treatment. Total flavonoid content decreased under the various drying methods, confirming that flavonoid content is heat-dependent. This finding was more pronounced for freezing and oven-drying (15.3 and 13.8 mg/g DW, respectively), with a 10% difference in the total flavonoid content between the two methods. Under leaching conditions, the flavonoid content decreased with increasing treatment time. Notably, roasting methods did not result in loss of flavonoid content. The total flavonoid content in the rapeseed varieties decreased in the following order: Youngsan, Tammi, Tamra, Naehan, Hanra, Mokpo No. 68, and Mokpo No. 111. CONCLUSION: The flavonoid content in rapeseed flower was higher in Youngsan than in the other varieties, under processing conditions such as freeze-drying, leaching at $90^{\circ}C$ for 5 min, and roasting.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.372-380
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• 2020

The purpose of this study is to investigate the physicochemical properties of jelly made from fermented red ginseng concentrate (FRGC) that can be easily absorbed and digested for the health promotion of the elderly. The pH of the jellies tended to decrease with increasing concentration of FRGC. Soluble solid content has significantly higher value when added more than 2%, and the water content of the sample was significantly lower when the FRGC was added 4%. As the amount of FRGC was increased, the total color difference increased, and the hardness of samples decreased significantly. On the other hand, the total ginsenoside contents of the FRGC was 45.50 mg/g. As the concentration of FRGC increased, the content of polyphenol and flavonoids increased. The increasing pattern of polyphenols and flavonoids showed a similar trend. As the content of FRGC increased, ABTS free radical scavenging activity significantly increased (p<0.05), and in the control, the minimum value (62.6 AEAC) and the 4% sample were highest (116.2 AEAC). DPPH radical scavenging activity was like that of ABTS radical scavenging activity. However, there was no significant difference in DPPH radical scavenging activity of 3% and 4% red ginseng jelly.

• Journal of Life Science
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• v.33 no.10
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• pp.835-841
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• 2023

To determine the characteristics of propolis fermented with microorganisms, the optimal conditions for propolis extraction with ethanol were first reviewed, and the physicochemical properties of the extracted propolis were then investigated. The shaking and stationary extraction methods were tested. The flavonoid content was 6.40 mg/g when the stationary extraction method was used and 6.95 mg/g when the shaking extraction method was used. The ethanol concentration was then varied, and the use of 50, 60, 70, and 80% ethanol resulted in the total flavonoid content in the propolis samples reaching 6.75, 8.45, 7.45, and 7.75 mg/g, respectively. This indicated that a 60% (v/v) concentration was optimal. As the extraction time was increased from 1 to 3 hr, the flavonoid content slightly increased; however, extending the extraction step to more than 3 hr did not significantly affect the flavonoid content. In terms of the extraction temperature, the highest concentration of flavonoids (8.63 mg/g) was detected at 50℃. In the propolis samples, 5.80, 2.61, and 1.32 mg/g of fructose, sucrose, and rhamnose were detected, respectively. As for the amino acid content, 17 amino acids, including glutamic acid, were detected, and the total amino acid content was 2.49 mg/g.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.650-659
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• 2014

Large quantities of Korean wild grape (Vitis coignetiae, KWG) pomace, a by-product of grape juice and wine manufacture, are generated annually, and disposal cost of KWG pomace is now increasing. Therefore, this study was conducted to determine total polyphenol, flavonoid, and anthocyanin content in whole KWG, KWG skin and KWG pomace and to identify and quantify flavonoids found in whole KWG and KWG pomace using LC/MS/MS. Spectral analysis showed high total polyphenol and flavonoid in KWG skin extracted with 75% ethanol (p < 0.05). KWG pomace had higher amount of total polyphenol, flavonoid and anthocyanin than whole grape (p < 0.05). Sixteen flavonoids were identified, but only 10 flavonoids were quantifiable from whole KWG and KWG pomace. Both epicatechin and rutin were the major flavonoids, and 521 or 147 ng/g of epicatechin (p < 0.05) and 305 or 110 ng/g of rutin (p > 0.05) were found in whole KWG and KWG pomace, respectively. The results show that KWG pomace is a very rich source of flavonoids, thus KWG pomace can be used as a functional food additive. Plans to include KWG pomace in food production are necessary.

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.266-270
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• 2007

This research was conducted to investigate antioxidant activities of Juglans mandshrica forages by the irradiation of far infrared ray during leaf drying processes before compound extraction, with its potential use for activating antioxidants. The contents of total phenolics and flavonoids in the basis of a gram leaf dry weight were maximized in 20 min at 30 V of far infrared irradiation. Total phenolic content was 25.43 mg/g in the FIR treatment, while it was 21.12 mg/g in the non-FIR treatment control. Total flavonoid content was 39.38 mg/g in the FIR treatment, while it was 32.78 mg/g in the non-FIR treatment control. The contents were decreased when the condition of far infrared ray irradiation was higher voltage and longer treatment time, exhibiting 16.93 mg/g of total phenolics and 23.78 mg/g of total flavonoids in 30 min at 50 V of far infrared irradiation. The antioxidant activities were shown to positive relationships with the contents of total phenolics and total flavonoids. In this study, we concluded that content of bioactive molecules relating antioxidant activity in Juglans mandshrica forages is optimized in 20 min at 30 V of far infrared irradiation for leaf drying process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.232-238
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• 2013

An experiment was conducted to determine the content of phenolics and flavonoids, antioxidant activity and antioxidant enzyme status for the extracts from 5 and 7-day old sprouts (DOS) of cowpea (Vigna unguiculata L. Walp). Total phenolics [mg ferulic acid equivalents (FAE) $kg^{-1}$ DW] content was highest in cotyledon extracts (48.8 mg $kg^{-1}$), followed by roots (30.8 mg $kg^{-1}$) and hypocotyl (22.2 mg $kg^{-1}$) extracts (p < 0.05) from 5 DOS. The result of total flavonoid level [mg rutin equivalents $kg^{-1}$ DW] had same tendency to the results of total phenolics, showing lower amount ranges. The antioxidant activity of the methanol extracts from all the plant dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in cotyledon extracts (82.5%) than in root (52.6%) or hypocotyl parts (35.0%) from 5 DOS. Among antioxidant enzymes, APX and CAT activities were highest in cotyledon part and POX and SOD activities in root part of 5 and 7 DOS. The results showed that total phenolics content ($r^2$ = 0.1516~0.9911) were more highly correlated with antioxidant activity than total flavonoids level ($r^2$ = 0.0113~0.9442), and that the level and activity of physiological-active substances were different depending on plant part of the sprout.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.123-126
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• 2008

The five flavonoids, isoqueritrin, juglanin, astragalin and 2-O-trans-p-coumaroyl astragalin were quantitatively analyzed in the leaves, unripe- and ripe fruits of four Korean Rubus species including Rubus crataegifolius, R. pungens var. oldhami, R. parvifolius, and R. coreanus belonging to the Rosaceae family. The HPLC analysis demonstrated that flavonoids are more abundant in the leaves than in the fruits. In the four Rubus species, ripe fruits generally contained similar or more amount of flavonoids than in unripe fruits. In particular, the quantity levels of total flavonoid (49.81${\pm}$0.50 mg/g) and isoquercitrin (35.08${\pm}$0.37 mg/g) were highest in the leaf of R. crataegifolius. In addition, the content of the flavonoids were quite low in the unripe fruits of R. coreanus that is most widely used as Rubi Fructus.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.106-106
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• 2019

Human needs energy to maintain metabolisms, and these energy sources were uptake foods or nutritions. The most effective source was known for glucose among the nutrients, furthermore the glucose is an important source of energy for blood cells and control brain maintenences cells. But as food is plentiful and eating habits become more westernized, fast food and irregular meal times by works. Nowadays, diabetes were rapidly increased by malnutriton and obesity. Diabetes was the sixth highest on the list of causes of death in Korea, released by the Statistics Korea in 2015, which is considered a serious social problem for adult diseases. Therefore, this study aims to establish the optimal hot water extraction conditions of mixed herbs extract mixture compounds that are effective in diabetes. The independent factors were extraction temperature (X1: $40-120^{\circ}C$), extraction time (X2: 2-10 hrs.), and the ratio of water to sample (X3: 40-200 mg/mL). Their effects were assessed on dependent variables of the extract properties, which included soluble solid contents, Brix of sample extract, total polyphenols content, total flavonoids content and DPPH Radical scavenging activity. As a result, the content of total polyphenol content was the highest in No.12(6 hrs, $120^{\circ}C$, 67 mg/mL) and the highest total flavonoid contents was found in No.16(6 hrs, $80^{\circ}C$, 40 mg/mL). DPPH Radical scavenging activity showed the highest activity in No.7(8 hrs, $100^{\circ}C$, 100 mg/mL).