• 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 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.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.

• Analytical Science and Technology
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• v.11 no.6
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• pp.478-484
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• 1998

Distribution of polyphenolic compounds in oak tree (Quercus acutissima, three years old) collected from Forest Research Institute located in Kwang Leung, Kyeonggi-do, Korea, was investigated using chromatographic studies. Total 25 polyphenolic fractions were separated from an oak tree, of which 15, 11, 7, 7, and 4 were in leaf, stem, root, bark, and seed, respectively. Catechins are predominant compounds in the polyphenols and some flavonoids were also identified. Distribution of polyphenols was relatively different in each part. Polyphenols in all of the part studied, except leaf where polymer was not detected, were existed as polymeric, oligomeric, and monomeric forms. Relative contents of total polyphenols in Quercus acutissima were the highest in bark, followed by root, leaf, acorn, and stem. Monomeric polyphenols were the predominant compounds present in all of the part of the oak tree.

• Journal of agriculture & life science
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• v.51 no.2
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• pp.47-59
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• 2017

The objectives of this study were to select the seeds of Cucurbitaceae and Solanaceae genotypes in terms of superior with bioactive compounds content and to inform sophisticated data for developing the high value-added products. We evaluated to aspects of the antioxidant activity, polyphenol content, and flavonoid contents in seeds from two vegetable family. We used in the Cucurbitaceae(watermelon, squash, bitter gourd, and sponge gourd) and Solanaceae(hot pepper, sweet pepper, and egg plant) the total 408 genotypes. In Cucurbitaceae, polyphenol content of watermelon and squash genotypes were ranged 19.9-343.8 and $6.1-81.2mg{\cdot}100g^{-1}\;DW$, respectively. The polyphenol content of watermelon genotypes was 12% among all genotypes over $160mg{\cdot}100g^{-1}\;DW$. The mean of flavonoid content in watermelon and squash genotypes represented 80 and $41.3mg{\cdot}100g^{-1}\;DW$, respectively. In Solanaceae, flavonoid content of hot pepper genotypes was ranged $64.4-472.5mg{\cdot}100g^{-1}\;DW$, with an average of $165.0mg{\cdot}100g^{-1}$. The 23 hot pepper genotypes were classified over 90% antioxidant activity. The antioxidant activity of sweet pepper was ranged 35.9-90.3%, and 23% of all genotypes represented 82% antioxidant activity. The polyphenol and flavonoid content of egg plant was ranged $38.1-642.0mg{\cdot}100g^{-1}\;DW$ and $14.2-1217.0mg{\cdot}100g^{-1}\;DW$, respectively. In addition, we selected that 8 egg plant with the superior genotypes for antioxidant activity, polyphenol, and flavonoid content. Results revealed that there was significant variation of antioxidant activity and bioactive compounds contents in both vegetable famaily. In addition, we suggested that selected genotypes seeds with high contain bioactive compounds will be more efficiency to develop natural value-added products.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.191-200
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• 2010

Anthocyanin and polyphenolic compounds present in fruits of mulberry (Morus alba L.) were determined and the influence of temperature and UV irradiation on stability of the anthocyanin-copigment complex were investigated. The copigmentation substance selected in non-anthocyanin fraction from mulberry for the study included: phenolic acid (hydroxybenzoic acid) and flavonoid (quercetin-3-O-$\beta$-D-glucopyranoside). The copigmentation effect increased with the copigment content. UV irradiation had a stronger degradation effect on the copigmentation complex than heating at $80^{\circ}C$. The non-anthocyanin fraction of mulberry and isolated flavonoid (quercetin-3-O-$\beta$-D-glucopyranoside) from mulberry fruit predominated over other copigment substances.

• International Journal of Industrial Entomology and Biomaterials
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• v.42 no.2
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• pp.25-32
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• 2021

Mulberry fruit (Morus alba L.) contains phytochemicals, including 1-deoxynojirimycin, quercetin-glucoside, kaempferol-glucoside, and anthocyanins, which have antioxidant effects. In this study, mulberry fruit extract was prepared at various temperatures (25-100℃) and water/ethanol solvent concentrations (0%-100% ethanol). Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism (CD) data indicated that the content of bioactive compounds such as polyphenols and flavonoids was lower in 100% ethanolic extracts than in 30%-50% ethanolic extracts. Radical scavenging activity determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-3-ethylbenzthiazoline sulfonic acid (ABTS) assays was highly correlated with polyphenol and flavonoid content. In conclusion, 30%-50% ethanolic extracts contained the highest contents of bioactive compounds and exhibited high levels of radical scavenging activity. These findings may inform the use of mulberry fruit extract as a functional food.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.745-752
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• 2001

Wild edible plants are consumed as raw or processed. Analytical data for raw biologically functional compounds were relatively well established. The changes on functional compounds during processing are, however, not well studied. This study was carried out to investigate the change of the quality of wild edible plants, Chamchwi, blanched at various conditions. Samples were blanched at the salt concentration of 0%, 1% or 2% for 1, 3, and 5 minutes each. The biologically active compounds, vitamin C, ${\beta}-carotene$, chlorophyll, flavonoids, polyphenols and minerals were analyzed. The concentration of vitamin C in Chamchwi did not show any significant change under various blanching conditions. Beta-carotene in Chamchwi was not significantly affected by blanching time. Higher salt concentration of blanching water, however, resulted in the increased concentration of ${\beta}-carotene$ in the blanched Chamchwi. Higher salt concentration of blanching water also reduced the loss of total flavonoids and total polyphenols from the blanched Chamchwi. The change of colors in the blanching water seemed to be corresponding to those of total flavonoids and total polyphenols concentrations in the blanching water.

• The Korean Journal of Food And Nutrition
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• v.30 no.1
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• pp.175-180
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• 2017

To enhance the physiological activities and reduce the off-flavor of garlic in the Kimchi, we manufactured the Kimchi seasoning replaced with 25~75% black garlic instead of raw garlic and measured the contents of antioxidants and antioxidant activities. The polyphenol compound content was $270.91{\mu}g/mL$ in the control and $278.18{\sim}305.75{\mu}g/mL$ in the Kimchi seasoning with black garlic. The polyphenol compound content increased by increasing the amount of black garlic in the Kimchi seasoning. The polyphenol compound contents gradually decreased during storage period. The flavonoid compound content was 26.18 mg% in the control and 26.80~38.72 mg% in the Kimchi seasoning replaced with 25~75% black garlic. The flavonoid compound contents increased by increasing the amount of black garlic. The flavonoid contents were different from those of polyphenol compounds during storage periods. In the case of DPPH electron donating abilities, DPPH electron donating ability of the control was 84.82%, which showed a lower antioxidative activity than the Kimchi seasoning replaced with black garlic. The electron donating abilities of the Kimchi seasoning replaced with black garlic were increased as the amount of black garlic was increased. In the lipid peroxidation test, the control showed no lipid peroxidation during the storage period. The Kimchi seasoning replaced with black garlic also inhibited lipid peroxidation during storage as in the control. However, it showed lower activity than the control. Reducing power was higher in the Kimchi seasoning replaced with black garlic than in the control. The higher the ratio of black garlic, the higher the reducing power.