• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.695-701
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• 2015

This study was conducted to evaluate the effects of drying and extraction methods on antioxidant activity and total phenol content of Gnaphalium affine D. DON (GA). Hot-air, shade-drying, and freeze-drying were used for drying, after which magnetic stirring and ultrasonification were applied. Extracting solvents were water, 80% ethanol, and 80% methanol. Total phenol content was highest in 80% ethanol extract of freeze-dried and stirred GA. Total flavonoid content was highest in 80% methanol extract of freeze-dried and stirred GA. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was higher in 80% methanol and 80% ethanol extracts than in water extract. 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was highest in 80% ethanol extract of shade-dried and ultrasonicated GA. Reducing power was generally higher in 80% methanol extract than in 80% ethanol and water extracts of GA. Total phenol and total flavonoid contents were highly correlated with DPPH radical scavenging activity and reducing power, respectively. This result implies that the antioxidant activity of GA can be attributed to phenol compounds such as flavonoids. Conclusively, phenol compounds such as flavonoids are responsible for the antioxidant activity of GA, and there was no significant effect of drying and stirring conditions on antioxidant activity of 80% ethanol. Meanwhile, DPPH radical scavenging activity of water extract and reducing power of 80% methanol extract were higher in hot-air and shade-dried GAs than in freeze-dried GA.

• 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.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.227-235
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• 2023

The current study evaluated the presence and concentration of health-promoting phenolic antioxidants in sorghum seed accessions from seven regions in three different countries (Uzbekistan, Myanmar, and the United States). The free radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl assay was 13.10±2.37 ㎍/mL in the Uzbekistan sorghum seed extracts, demonstrating the highest antioxidant activity. Additionally, the total phenol content was the highest in the Uzbekistan sorghum seed extracts [157.87±4.04 mg GAE/g (gallic acid equivalents per gram)]. The total flavonoid content was 12.69±0.72 mg QE/g (quercetin equivalents per gram) and represents the highest value in the Myanmar collection. The Uzbekistan collection demonstrated the greatest potential for whitening activity, with the tyrosinase inhibition rate of 79.20±4.15%. The wrinkle improvement function using elastase also showed the highest anti-aging activity of 55.85±4.78% in the same seed extract. The Uzbekistan seed extract had the highest NO production inhibitory activity of 144.35±4.55%. We conclude from these results that the Uzbekistan sorghum seed has excellent antioxidant activity, content of various functional ingredients, and anti-inflammatory activity.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.186-194
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• 2016

Consumption of fruits and vegetables has been conducted to be effective in the prevention of chronic diseases. In this study, 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v) were used as solvents in the extraction of apple peels. The total phenol content, total flavonoid content and antioxidant activity of various extracts were investigated using in vitro assays. The extract obtained by 70% methanol showed the highest total phenol content ($20.87{\pm}0.17mgCAE/g$), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity and ferric reducing antioxidant power. However, 70% ethanol extract possessed the strongest antioxidant activity assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ${\beta}$-carotene bleaching method. And CM extract was found to show the highest total flavonoid content with the value of $9.26{\pm}0.06mgQE/g$. These results indicated that apple peels can be used in dietary applications with a potential to reduce oxidative stress.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.295-301
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• 2008

In this study, the antioxidant activities of red pepper seed kimchi extracts were examined. The extracts were evaluated by various antioxidant assays that included determinations of total phenolic and flavonoid contents, DPPH radical scavenging, superoxide anion radical scavenging, nitric oxide scavenging, superoxide dismutase (SOD) activity, metal chelating activity, and reducing power. All the kimchi extracts showed strong antioxidant activities by the tested methods. The 7% red pepper seed kimchi that was fermented for 6 days possessed the highest activity according to the performed tests. Yet, the highest scavenging activity was exhibited against nitrite, by extracts from kimchi for 0 day of fermentation rather than 6 days. All the activities for the kimchi fermented for 0 day with the addition of 7% red pepper seed increased markedly with an increase in concentration. With the exception of metal chelating and SOD activities, for the antioxidant properties assayed, the red pepper seed kimchi extracts were found to be highly effective.

• KSBB Journal
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• v.29 no.2
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• pp.92-97
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• 2014

In this study, we investigate the antimicrobial and antioxidant activities of extracts of Enteromorpha intestinalis. To evaluate the antimicrobial and antioxidant activities, three solvents (hexane, chloroform and methanol) were applied to obtain extracts. The extraction yields are hexane (A) 1.11%, chloroform (B) 0.94%, and methanol (C) 8.2%. Also, the contents of total phenolic compounds of extract A, B, C are 4.03%, 8.15%, and 2.33%, respectively. In the results of antimicrobial activity, extract A and B have higher activity than that of extract C. Especially, Vibrio vulificus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli are more sensitive than others. In antioxidant activity, extract A and B present the higher DPPH activity than that of control (BHA and ascorbic acid). The DPPH radical scavenging activity and SOD-like activity are ordered as B>C>A. However, extract C show high value in ferric reducing antioxidant power assay. In nitrite scavenging activity, extract A is relatively higher than others. However, the antioxidant activities are lower than that of controls (ascorbic acid and BHA). The antioxidant activities are presented the increasing pattern of increasing by the increasing of extract concentration.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.580-584
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• 2007

Actinidia arguta extracts obtained from three cultivars ('Sae-Han', 'Dae-Sung', and 'Chil-Bo') were assayed for their antioxidant properties and nutritional composition. Antioxidant activity of the extracts was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Total phenolic contents of the extracts were determined by the Folin-Ciocalteu method. Vitamin C (L-ascorbic acid) content measured by a colorimetric method and reducing sugar content estimated by dinitrosalicylic acid (DNSA) method. Crude extracts from A. arguta 'Sea-Han' showed the most potent radical-scavenging activity showing 86.55% at 10 mg/ml. The DPPH radical scavenging activity of extracts and solvent fractions from Sea-Han cultivar was in decreasing order of EtOAc fraction>BuOH fraction>$CH_2Cl_2$ fraction>hexane fraction, among which EtOAc fraction showed the highest antioxidant activity (87.51 % at 5 mg/ml). Total phenolic contents in A. arguta 'Sae-Han', 'Dae-Sung' and 'Chil-Bo', were 32.93, 28.23, and 25.60 mg/g, respectively. Vitamin C contents of them were 840.57, 578.81 and 730.10 ug/g, respectively.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.355-360
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• 2016

The influence of extraction temperature, powder concentration, and extraction time on the antioxidant properties of aqueous ginger extract was investigated. The possibility of estimating the antioxidant properties of the extract from its absorbance and colour properties was also investigated. Results indicated that powder concentration was the most significant factor to consider in optimizing antioxidant extraction. However, temperature and time still influenced the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity while extraction temperature influenced the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extract. Using the total phenol content, total flavonoid content, ABTS radical scavenging activity, and DPPH radical scavenging activity of the extract, the multiresponse optimization condition for extraction of antioxidant based on the experimental range studied is $96^{\circ}C$, 2.10 g/100 mL, and 90 min. The absorbance of the ginger extract at 610 nm could be exploited for rapid estimation of its total flavonoid and polyphenol with a $R^2$ of 0.713 and 0.753, respectively.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.88-97
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• 2017

This study explored the physicochemical and nutritional changes associated with storage duration of fresh tomatoes. Fruits of the 'TY Megaton' and 'Yureka' tomato cultivars were harvested at the pink stage and stored at $12^{\circ}C$ for 20 days. During storage, firmness, weight loss, skin color (Hunter L, a, b, a / b values), soluble solids content (SSC), titratable acidity (TA), pH, antioxidant contents (lycopene, ascorbic acid, and total phenolics) and antioxidant activity were evaluated. Firmness was above the minimum marketable limit and fresh weight loss was below maximum acceptable weight loss after 3 weeks of storage, and no deleterious effect on antioxidant contents or activities were observed. Significant differences in SSC, TA, and pH were seen between varieties, but not between fruits stored for different durations. In both varieties, Hunter a values increased more than five-fold after 8 days of storage; this correlated with a more than four-fold accumulation of lycopene after two weeks of storage. The antioxidant activity of tomatoes was highest at the beginning of the storage period, likely because of the effective DPPH - reducing power of ascorbic acid and total phenolics. Antioxidant activity increased after 12 days of storage because of increasing lycopene content. Hence, this study indicates that pink - stage tomatoes may be stored at $12^{\circ}C$ for up to 3 weeks without affecting marketability or nutritional value.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.130-134
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• 2015

In this study, to confirm the physiological activity of the grasshopper (Oxya chinensis sinuosa) antioxidant activity, antimicrobial activity, thermal stability of the antimicrobial substance, pH stability, total polyphenol content of the adult grasshopper was measured. Antibacterial activity in accordance with the extraction solvent showed a strong antibacterial activity in a mixed solvent of ethanol for the E. coli strain. Antimicrobial activity in $40^{\circ}C$ hot air drying and a freezedried condition was the highest and there was no difference in the gender. Antibacterial substance was stable to heat and pH. Antioxidant activity of the grasshopper exhibited a high activity in the 50% and 70% ethanol extract. Total polyphenol content was the 12 ~17 mg / 100 g and there was not great difference according to the drying conditions and gender.