• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.278-278
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• 2017

Brown rice grains are increasingly attended by consumers due to their potential health benefits of antioxidant capacity. Therefore, this research was carried out to evaluate the antioxidant activity of brown rice in Korea-native weedy rice germplasm. Two hundred and twenty one accessions of weedy rice used in this study were received from the National Agrobiodiversity Center of RDA, and were regenerated in the experimental field of Chonbuk National University. The sampled seeds were extracted using methanol and the extracts were analyzed using the 1, 1-dipheny-2-picrylhydrasyl (DPPH) free radical scavenging assay for antioxidant capacity determination. Among the all germplasm, the samples of seed coat in red colour, white colour, red -white mixing colour and brown colour were 171 (81%), 26 (12%), 12 (6%) and 2 (1%), respectively. The antioxidant activity values of all samples were varied in the range from 22.31% to 95.53 % and mean value was 82.09%. Depend on the seed coat colour, the average antioxidant activity of the extract of weedy rice seeds indicated that the following order in seed coat colour: red colour (89.11%) > the red-white mixing colour (70.67%) > brown colour (53.16%) > white colour (45.99%). The antioxidant activity of red coloured weedy rice were significantly higher than those of the others. It is suggested that Korea-native weedy rice accessions with high antioxidant activity could be developed as a potential functional food material by further research of component analysis.

• Korean journal of food and cookery science
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• v.24 no.3
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• pp.358-366
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• 2008

The antioxidant properties of red ginseng extracts prepared under different extraction conditions were evaluated by a variety of antioxidant assays, including $DPPH^{\cdot}$ radical scavenging, $ABTS^{+\cdot}$ radical scavenging, superoxide anion scavenging, nitrite scavenging and reducing power activities. The contents of total phenolic compounds and flavonoids were also determined. The various antioxidant activities were compared to positive controls such as Trolox, tannic acid and ascorbic acid. The antioxidant activities of all of the extracts were shown to be the highest in the ethanol extract. The antioxidant activities of the red ginseng powder were the lowest among the samples. The amounts of total phenolic compounds and flavonoids were at a maximum in the ethanol extract. Correlation analysis demonstrated the existence of a linear relationship between free radical scavenging activities and the phenolic compounds contents of extracts. The antioxidant activity of yogurt was increased as the result of the addition of red ginseng extract. The quality characteristics of the yogurt to which red ginseng extract was added were similar to those of yogurt without red ginseng extract. The overall sensory score and color of yogurt made from 0.5% red ginseng was the best of the tested yogurts. In accordance with the antioxidant activity and quality characteristics, the optimal concentration of red ginseng extract was approximately 0.5%.

• Food Science of Animal Resources
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• v.34 no.6
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• pp.769-776
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• 2014

The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than $70^{\circ}C$. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.372-378
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• 2012

Xanthium sibiricum using extracts antioxidant activity and antimicrobial activity were analyzed and the following results were obtained. Antioxidant activity using DPPH as a VLC column fractionation experiments XS-5 (water fraction of Xanthium sibiricum) concentration in the 500 ${\mu}g/ml$ to 87.53 percent in the highest antioxidant activity was found, VLC fractionation in XS-3-2 (eluted with chloroform/methanol 7~10%) concentration of 500 ${\mu}g/ml$, showed the antioxidant activity of 78.72%. The antioxidant activity measured by PCL XS-1 (n-hexane fraction of Xanthium sibiricum) XS-5 (water fraction of Xanthium sibiricum) and 13.32 nmol open column XS-3-2 (eluted with chloroform/methanol 7~10%) showed antioxidant activity with 14.34 nmol. The antimicrobial activity against Candida albicans XS-2 (methlene chloride fraction fo Xanthium sibiricum) is the concentration of 500 ${\mu}g$/disc 1 mm of the clean zone was formed. XS-3 (ethanol fraction fo Xanthium sibiricum) in the antioxidant activity using DPPH and PCL had higher antibacterial activity was low.

• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.291-298
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• 2014

The aim of this study was to investigate the antioxidant activity of orange (Citrus auranthium) flesh (OF) and peel (OP) extracted with acetone, ethanol, and methanol. Antioxidant potential was examined by measuring total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA), total radical-trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and cellular antioxidant activity (CAA). The comet assay was used to determine the protective effects of OF and OP against $H_2O_2$-induced DNA damage. TPC was highest in the acetone extracts of OF and OP. DPPH RSA was also higher in the acetone extracts than in the ethanol extracts. The DPPH RSA was highest in the acetone extracts of OF. The TRAP and ORAC values of the all extracts increased in a dose-dependent manner. In the TRAP assay, the acetone extracts of OF and OP had the lowest $IC_{50}$ values. In the CAA assay, the methanol and acetone extracts of OP had the lowest $IC_{50}$ values. All of the samples protected against $H_2O_2$-induced DNA damage in human leukocytes, as measured by the comet assay, but the acetone extracts of OP had the strongest effect. These results suggest that acetone is the best solvent for the extraction of antioxidant compounds from OF and OP. Furthermore, the high antioxidant activity of OP, which is a by-product of orange processing, suggests that it can be used in nutraceutical and functional foods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.102-107
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• 2002

Cereal grains are rich in phenolic compounds that give beneficial effect in human health. Although several research works have been reported on the effects of phytochemicals of plant origin, such as fruits, vegetables, few studies have examined the antioxidative effects of whole cereal grains. The objective of this study was to determine total antioxidant capacity of 80% ethanolic extracts of cereal grains by testing the ability of the extracts to inhibit UV -induced lipid peroxidation in vitro using linoleic acid in comparison to well-known antioxidant such as ascorbic acid and tannic acid. The total phenolic content of the cereal grain (80% ethanolic extracts) investigated in this study varied from 2.1 mg/g (wheat cv. Olgeurumil) to 10.4 mg/g (barely cv. Seodunchalbori). Highly positive relationship between total phenol compounds and antioxidant activity was found. When the antioxidant activities of all investigated extracts were measured with application of same quantity of phenol compounds, oat grain extracts showed similar antioxidant activity of barely cultivars. However, barely extract appeared as the most potent antioxidant activity of inhibition of UV -induced lipid peroxidation. This indicated that factors such as phenolic compound composition and their individual antioxidant activity could playa crucial role in the total antioxidant activity of cereal grains.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1367-1374
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• 2016

The present study evaluated the total phenolic and flavonoid contents as well as total antioxidant capacity (TAC) of three cultivars of Actinidia arguta Planch. kiwi berries; cv. Mansoo (Mansoo), cv. Chiak (Chiak), and cv. Haeyeon (Haeyeon). In addition, the anti-inflammatory effects of the three cultivars of kiwi berries were investigated using a lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cell line. Mansoo had the highest total phenolic content and TAC among the three cultivars, whereas Chiak had the highest total flavonoid content. The total antioxidant capacities of the kiwi berry extracts were more strongly correlated with total phenolic content than with total flavonoid content. The kiwi berry extracts suppressed the secretion of pro-inflammatory cytokines, including interleukin-6 and tumor necrosis factor-α, from LPS-stimulated RAW 264.7 cells. The release of nitrite, an indirect indicator of nitric oxide, was also ameliorated by pre-treatment with the kiwi berry extracts in a dose-dependent manner. Cellular-based measurements of antioxidant capacity exhibited that the kiwi berry extracts had cellular antioxidant capacities. Such cellular antioxidant effects are possibly attributed to their direct antioxidant capacity or to the inhibition of reactive oxygen species generation via anti-inflammatory effects. Our findings suggest that kiwi berries are potential antioxidant and anti-inflammatory agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.98-104
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• 1995

To utilize the mackerel viscera effectively, antioxidant substances were extracted and the effects on the oxidation were evaluated. Total lipid(TL) extracted from mackerel viscera were fractionated into hexane extracts, tetracarbon chloride($CCl_4$)-methanol(1 : 1, 1 : 3, 1 : 9, v/v) extracts, phospholipid(PL), phosphatidylcholine(PC), and PC free fracitons(PCF). Inhibition of fish oil oxidation was investigated using these fractions. Hexane fraction showed lower antioxidant activity compared to the TL or $CCl_4-methanol$ fractions(C-M) ; in addition, antioxidant activities increased as polarity of C-M increased. Significant antioxidant activities were observed with PL, PC, and PCF ; among them, PC was the most effective. To determine the antioxidant activity of PC, effects of natural or synthetic antioxidant were compared. Addition of PC to fish oil proved to enhance antioxidant activity the antioxidant activity of phospholipids was derived mainly from PC.

• Journal of Pharmacopuncture
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• v.24 no.1
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• pp.24-31
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• 2021

Objectives: Accumulation of cellular reactive oxygen species (ROS) leads to oxidative stress. Increased production of ROS, such as superoxide anion, or a deficiency in their clearance by antioxidant defences, mediates cellular pathology. Grewia Spp fruits are a source of bioactive compounds and have notable antioxidant activity. Although the antioxidant capacity of Grewia Spp has been studied, there is very limited evidence that links the antioxidant activities of Grewia bicolor and Grewia flava to the inhibition of free radical formation associated with damage in biological systems. Methods: This study evaluated the protective effects of Grewia bicolor and Grewia flava extracts against free radical-induced oxidative stress and the resulting cytotoxicity effect using HeLa cells. Antioxidant properties determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic content (TPC) assays showed significantly higher (p < 0.05) antioxidant activity in Grewia flava (ethanol extract) than Grewia flava (water extract) and Grewia bicolor (ethanol and water extracts). Results: Using 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide or MTT assay, cytotoxicity results showed that extracts of Grewia bicolor and Grewia flava were less toxic to HeLa cells at tested concentrations compared to the untreated control. This confirmed the low toxicity of these edible fruits at the tested concentrations in HeLa cells. Furthermore, hydrogen peroxide (H2O2)-induced cell loss was effectively reduced by pre-incubating HeLa cells with Grewia bicolor and Grewia flava extracts, with Grewia flava (ethanol extract) revealing better protection. Conclusion: The effect was speculated to be associated with the higher antioxidant activity of Grewia flava (ethanol extract). Additional studies will warrant confirmation of the mechanism of action of such effects.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.305-305
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• 2022

In this study, 139 Korean landrace sorghum germplasms collected in 10 different Korean regions were analyzed for tannin, total phenolic contents(TPC), and antioxidant activities using three assays including ABTS, DPPH, and FRAP. The Korean landrace sorghums showed significant variations of metabolite contents and antioxidant activities by collection regions. Gyeonggi sorghum had the highest tannin and TPC contents with 273.73%, 7.395mgGAE/g, respectively. Therefore, three assays of antioxidant activities of Gyeonggi sorghum, which is highly related to tannin and TPC, were also significantly higher than others. However, Gyeongnam sorghums showed the lowest tannin and TPC with 148.34% and 3.482mgGAE/g, thus, three antioxidnat activities showed the lowest levels. Three accessions(IT322580, IT340261 and IT329053) had the highest tannin levels over 400%, but, two accessions (IT322613, IT270366) showed less than 1% of tannin content. Four accessions (IT270349, IT286448, IT331878, and IT251882) showed the highest level of TPC over 9mgGAE/g. In this study, antioxidant activities with three assays were strongly related to tannins and TPC, and TPC showed higher significance than tannin with all three antioxidant activities. The germplasms with the highest overall antioxidant activity were IT270349, IT340261, and IT286448, which had the highest levels of tannin and TPC. The principal component analysis presented that 2 sub-populations were divided. Gyeonggi and Gangwon Yeongseo sorghums, which had high metabolite contents and antioxidant activity levels, were mainly included in group 1. Gyeongnam and Jeonnam sorghums, which had low metabolite and antioxidant activity levels, were mainly included in group 2. This results could contribute to discover breeding metarials for the development of functional sorghum varieties.