• Food Science and Preservation
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• v.21 no.4
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• pp.593-599
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• 2014

This study was conducted to determine the antioxidant potentials of some available plants to source alternate antioxidants and antibiotics. The antioxidant activity was evaluated by determining the antioxidant activity reducing powers and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities of extracts from some local edible native plants. The DPPH radical scavenging activity of the extracts was found to have been 0.41-94.84%. The Elsholtziasplendens NAKAI extract ($85^{\circ}C$, ethanol, accelerated solvent extraction) showed the highest level of antioxidant activity. Eight samples of plant extracts were evaluated for their antimicrobial activities against three microflora (Bacillus subtilis, Escherichia coli, and Candida albicans) using disc diffusion assay. Two samples (Geranium krameri FR. Et SAV. and Cleyera japonica Thunb.) had much more intensive antimicrobial activities than the control. However, their DPPH free radical scavenging activity levels were only 14.50 and 13.85, respectively. It is suggested that they could be used as natural preservatives against bacterial contamination in cosmetics and foods, in place of the common synthetic preservatives currently used.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.673-682
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• 2017

Protein hydrolysates derived from plants and animals having antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was fractioned to hydrolysis of Ogae egg white protein using the ultrafiltration. The antioxidant activity of the produced peptides was analyzed. As a result, the maximum value of DPPH radical scavenging was 1 kDa(70.83 %), hydroxy radical scavenging was 5 kDa(47.01 %), superoxide anion radical scavenging was 5 kDa(40.57 %), and $Fe^{2+}$ chelation ability was 5 kDa(29.87 %). Furthermore, the antioxidant Inhibition concentration ($IC_{50}$) of peptides was evaluated for each fraction. As a result, the maximum value of HDS was superoxide anion radical scavenging($IC_{50}$, 5.42 mg/ml). 1 kDa was $Fe^{2+}$ chelation ability($IC_{50}$, 1.67 mg/ml), 5 kDa was $Fe^{2+}$ cheating ability($IC_{50}$, 2.09 mg/ml), 10 kDa was $Fe^{2+}$ cheating ability($IC_{50}$, 2.61 mg/ml), papain was $Fe^{2+}$ cheating ability($IC_{50}$, 4.53 mg/ml). Therefore, we expect that peptides produced from Ogae egg white protein using 5 kDa fraction are useful as an antioxidant functional food ingredients.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.215-220
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• 2017

Xanthium strumarium L. is an annual plant belongs to the family Asteraceae which is is called a 'Cocklebur' that is used for medicinal purposes. Convergent phyto-activity of various extracts of Xanthium strumarium L. (Asteraceae) was examined. We estimated antioxidant activity from ground part and fruit extract of X. strumarium using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and ABTS assay. The extract of X. strumarium was separated each fraction that of ethanol, petroleum ether, and ethyl acetate. It showed potent radical scavenging effect against the DPPH radical and ABTS. The study revealed that X. strumarium could be used as a potential source of natural antioxidant.

• Journal of the Korean Society of Food Culture
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• v.32 no.2
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• pp.144-149
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• 2017

This study was designed to investigate the contents of icariin during ripening of Epimedium koreanum with sugar and Soju (25, 30, and 35% alcohol contents) using a homemade method. Contents of icariin of Epimedium wine were examined using high performance liquid chromatography. Icariin levels in Epimedium wine increased during the first 3 days of storage; after 6 days, icariin contents decreased gradually until 30 days. Contents of icariin in Epimedium wine by storage temperature (5 and $20^{\circ}C$) were not different during storage. After 30 days, icaiin was not detected in all tested Epimedium wines. Epimedium wines were assessed for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and (ABTS) radical scavenging activity. DPPH and ABTS radical scavenging activities increased in early storage periods, however, after 6 or 9 days, activities decreased gradually.

• Human Ecology Research
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• v.62 no.2
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• pp.295-302
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• 2024

This study analyzed the quality characteristics of nutritional bars with varying concentrations (0, 0.5, 1.5, 2.5%) of Enteromorpha intenstinalis powder added. To achieve this, color analysis, an assessment of DPPH radical scavenging activities, and sensory evaluations were performed. The results revealed that as the amount of Enteromorpha intestinalis powder (EIP) increased, pH and lightness values decreased. DPPH radical scavenging activities of 75.26%, 56.11%, 71.59%, and 62.49% were exhibited for the 0%, 0.5%, 1.5%, and 2.5% concentrations, respectively at 50 mg/mL. Significant differences were observed between the samples with respect to the color, appearance, texture, taste, and overall preference for the nutritional bars. Overall preference was highest for the nutritional bar with 1.5% Enteromorpha intenstinalis powder added. Therefore, adding 1.5% of Enteromorpha intenstinalis powder to a nutritional bar is most suitable for enhancing preference and quality characteristics.

• 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.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.451-460
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• 2017

This study optimized the extraction of antioxidants from Gugija (Lycium chinensis Mill). To determine operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), response surface methodology was applied to monitor yield, anthocyanins, flavonoids and DPPH radical scavenging activity. Coefficients of determinations ($R^2$) of the models were range of 0.8645~0.9859 (p<0.01~0.1) in dependant parameters. Yield of Gugija extracts was maximized 23.12% in extraction conditions of 4.22 h at 8.25% ethanol. Anthocyanins was maximized 1.43 (OD in 530 nm) in extraction conditions of 3.06 h at 79.98% ethanol. Flavonoids was maximized $3,100{\mu}g/100g$ in extraction conditions of 3.37 h at 67.02% ethanol. DPPH radical scavenging activity was maximized 96.93% in extraction conditions of 1.67 h at 69.81% ethanol. Optimum extraction conditions (2.5 h extraction at 70% ethanol) were obtained by superimposing the contour maps with regard to anthocyanins, flavonoids and DPPH radical scavenging activity of Gugija. Maximum values of anthocyanins, flavonoids and DPPH radical scavenging activity in optimum extraction condition were 1.0080 (OD in 530 nm), $3,145{\mu}g/100g$, 96.96%, respectively. But values of anthocyanins, flavonoids and DPPH radical scavenging activity in water extraction condition (1 h at water) were 0.4652 (OD in 530 nm), $1,633{\mu}g/100g$, 86.98%, respectively.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.337-342
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• 2012

The purpose of this study was to investigate total polyphenols, total flavonoid, and DPPH radical scavenging activity in 26 species of Korean natural plants and 14 species of medicinal plant extracts. The plant containing the highest total polyphenols and total flavonoids were Plantago asiatica, and Lespedeza cuneata G. Don, respectively. The content of polyphenols and flavonoids in natural plants was the highest in Lespedeza cuneata G. Don, which also demonstrated high DPPH radical scavenging activity. In medicinal plant extract, Saururus chinensis (Lour.) Baill and Artemisiae Asiaticae Herba had the highest level of total polyphenols (194.60 and 203.92 mg/g extract, respectively) and DPPH radical scavenging activity. Diospyros kaki Thunb and Dryopteris crassirhizoma did not contain high levels of total polyphenols (112.98, 121.46 mg/g extract, respectively) and flavonoids (46.10, 58.69 mg/g extract respectively), but DPPH radical scavenging activity was relatively high. Further study regarding plants that exhibit higher total polyphenols, total flavonoid, and DPPH radical scavenging activity is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1649-1655
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• 2009

The antioxidant activities of water extracts from wild vegetables such as Ligularia fischeri (GC), Capsicum annuum L. (GCY), Aster scaber (CNM), Petasites japonicus S. et Z. Max (MYD), Ipomoea batatas L. (Lam) (GGM) were evaluated and compared with water extracts from freeze dried block. The antioxidant properties of water extracts from wild vegetables and their freeze dried block were evaluated using different antioxidant tests; 2.2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and nitrite scavenging activities. The water extracts from wild vegetables were found to have a higher total phenolic content than water extracts from freeze dried block. Total phenolic contents of water extracts from GC, GCY, CNM, MYD, and GGM were $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;{\mu}g/mg\;and\;122.67{\pm}3.51\;{\mu}g/mg$, respectively. At the concentrations of 1000 ppm, water extracts from GC, GCY, CNM, and GGM showed higher activities than water extracts from their freeze dried block on DPPH radical scavenger activity. The activity of water extracts from CNM, GC, GCY, MYD, and GGM were 90.9%, 89.9%, 76.6%, 71.1%, and 57.4%, respectively. When 10000 ppm of GC, GCY, CNM, MYD, and GGM water extracts tested for hydroxyl radical scavenging activity, activities were increased by 38.8%, 33.4%, 35.9%, 34.3%, and 33.8%, respectively and a similar effect was found with water extracts from GCY, CNM, and GGM freeze dried block at 10000 ppm concentration. However, the water extracts from GC and MYD was slightly more effective than freeze dried block extracts. The water extracts from wild vegetables and their freeze dried block had effective DPPH radical scavenger activity and hydroxyl radical scavenging activity at all tested concentrations. Nitrite scavenging activity of GC water extract significantly increased in a dose-dependent manner and the extract had higher nitrite scavenging activity than extracts freeze dried block extracts. We found that freeze dried block maintained antioxidant activities of the wild vegetables.

• Natural Product Sciences
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• v.7 no.1
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• pp.1-4
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• 2001

The antioxidant activity of Pinus densiflora was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The methanol extract of P. densiflora showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate>n-butanol>water>dichloromethane> n-hexane fraction. The ethyl acetate soluble fraction exhibiting strong antioxidant activity was further purified by repeated silica gel column chromatography. Antioxidant (+)-catechin was isolated as one of the active principles from the ethyl acetate fraction, together with the inactive components, dihydrokaempferol and 1-O-benzoylglucose. The radical scavenging effect of (+)-catechin on DPPH radical exceeded to that of L-ascorbic acid which is a well known antioxidant.