• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.521-528
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• 2016

The antioxidant activity of 70% methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts from turmeric (Curcuma longa L.) was investigated in this study. The antioxidant potential of various extracts of turmeric was evaluated by using different antioxidant tests, namely DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, ferric reducing antioxidant power and ${\beta}$-carotene bleaching assays as well as total phenol content and total flavonoid content. All extracts exhibited abundant total phenol content, total flavonoid content and strong antioxidant activity. Particularly, higher activity was exhibited by CM extract with $46.32{\pm}0.35mgCAE/g$ and $15.58{\pm}0.39 mgQE/g$ of total phenol content and total flavonoid content. Generally, antioxidant activity of various extracts from turmeric increased in the following order: 70% methanol extract, 70% ethanol extract and CM extract, respectively. Results suggested that turmeric could be widely used as a source of antioxidant and a kind of functional material in food.

• Food Engineering Progress
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• v.14 no.4
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• pp.342-345
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• 2010

The purpose of current study was to examine bioaccessibility of antioxidant activity and total phenolic content in each part of water spinach (Ipomoea aquatic Forsk.). In vitro biomimicking system simulated human digestive fluid was employed in order to measure bioavailable anti-oxidative effect and phenolic content. Antioxidant activity and total phenolic content was measured by using the DPPH method and the Folin-Ciocalteu assay, respectively. Stem of water spinach had a higher DPPH free radical scavenging effect (5.43 mg/mL for $IC_{50}$) than leaf (5.95 mg/mL for $IC_{50}$), while leaf had a greater level of total phenolic content (287.45 ${\mu}g$ GAE/mL) than stem (216.45 ${\mu}g$ GAE/mL). Bioaccessible antioxidant capacity and digestive stability of total phenolic content showed a similar pattern to what found in raw materials. Our result also indicated that total phenolic content was not found to be a major marker for prediction of antioxidant activity. It is plausible that other constituents such as vitamin E and C in water spinach could be contributors for antioxidant activities.

• Journal of Apiculture
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• v.32 no.4
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• pp.327-332
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• 2017

In this study, we studied the changes in antioxidant activity of Actinidia arguta fruit of Autumn Sense cultivar during fruit ripening. The aim of this investigation was to find the knowledge of the changes of physiochemicals associated with fruit quality, antioxidant properties (free-radical scavenging activity and reducing power), total phenolics and vitamin C during fruit ripening. The highest free-radical scavenging activity (at $100{\mu}g/ml$) and reducing power (at $100{\mu}g/ml$) in A. arguta fruit were 78.57% and 0.22, respectively. Total phenolic content and vitamin C content in fruit of 10 days after fruit set were $639.48{\mu}g/g$ and $1052.2{\mu}g/g$, respectively. In general, the antioxidant activity and the related parameters, including total phenolic content and vitamin C content decreased during fruit ripening. These results improve knowledge of the effect of ripening on the antioxidant activity and related compounds contents that could help to establish the optimum A. arguta fruit harvest data for various usages.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.451-456
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• 2007

The potential antioxidant activities of methanolic extracts from soybean and rice fermented with Monascus sp. were investigated. M. pilosus IFO 480 and M. anka IFO 478 were screened as a suitable strain to promote the antioxidant activities in soybean- and rice- fermentation. The methanol extracts from soybean and rice after fermenting for 20 days at $30^{\circ}C$ resulted in a significant increase in the antioxidant capacities expressed as radical (ABTS and DPPH) scavenging assay and peroxidation inhibition (%) by thiocyanate method and increased (p<0.01) by a 2.6 to 3.1-fold compared with those of the unfermented products. The average antioxidant potentials of Monascus-fermented soybean extracts (MFSE) were significantly (p<0.01) stronger than Monascus-fermented rice extracts (MFRE). A linear correlations between free radical scavenging activity of MFSE and the total phenolics content (r=0.84) and total flavonoids content (r=0.81) were observed. These results indicated that MFSE exhibited stronger (p<0.01) antioxidant activity and contained significantly higher levels (p<0.05) of phenolics than MFRE.

• Natural Product Sciences
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• v.10 no.1
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• pp.16-19
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• 2004

Triphala churna is a widely used herbal formulation that contains equal proportion of dried fruit powder of Emblica officinalis, Terminalia chebula and Terminalia belirica. In the Indian system of medicine, it is used in cleaning wounds, urinary disorders, diabetes mellitus, leprosy, constipation, eyesight promotion, piles, and as a rejuvenator. In the present study, the methanolic extract of 5 commercial Triphala was evaluated for antioxidant activity by 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging method, total phenolic content by Folin-Ciocalteu method and gallic acid equivalents (GAE) by high performance thin layer chromatographic (HPTLC) method. All extracts exhibited antioxidant activity significantly. The $IC_{50}$ of the extracts ranged between $7.16\;to\;12.96\;{\mu}g/ml$. The total phenolic content of the extracts was found to be 195.3-296.4 mg of GAE/gm of GAE/gm dw. The HPTLC chromatographic data reveal that the content of GAE present in the extract was found to be $7.17-4.11\;{\mu}g/ml$. The study reveals that out of the churnas analysed, C was found to exhibit the most potent antioxidant activity. A clear correlation between $IC_{50}$ and content of GAE nor the total phenolic content could be observed. The study reveals that the consumption of Triphala would exert several beneficial effects by virtue of its antioxidant activity.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.89-92
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• 2022

In this study, the effects of soil conditions on antioxidant activities of the aerial and underground parts of rosemary were assessed to determine the most effective soil conditions for cultivation. The antioxidant activity was the highest (51.58±2.93 ㎍/mL) when cultivated in the mixture of gardening soil and vermiculite using DPPH assay. The antioxidant activity of underground parts the highest (127.48±12.38 ㎍/mL) when cultivated in the mixture of soil, vermiculite, and perlite. ABTS assay showed that the antioxidant activity of aerial parts was 230.34±57.93 ㎍·mL^-1 when cultivated in the mixture of gardening soil and vermiculite and that of underground parts was 320.98±16.04 ㎍·mL^-1 when cultivated in the mixture of gardening soil, vermiculite, and perlite. The total phenolic content of aerial parts was the highest (155.25±2.96 mg GAE/g) when cultivated in the mixture of gardening soil. The total flavonoid content of aerial parts was the highest (67.32±5.27 mg QE/g) when cultivated in the mixture of gardening soil. Therefore, the mixture of gardening soil, vermiculite, and perlite is superior to gardening soil alone for cultivation of rosemary to increase its antioxidant activity as well as total phenolic and flavonoid content.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.286-292
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• 2012

We investigated the effect of various cooking methods (boiling, steaming, stir-frying, and roasting) and three cooking times (5, 10, and 15 min) on the antioxidant properties of red pepper. Raw and cooked peppers were measured for proximate composition, ascorbic acid (AsA) content, total carotenoid content (TCC), total polyphenol content (TP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities. Results showed that the proximate composition, AsA content, TCC, TP, and antioxidant activities were significantly (p<0.05) affected by the cooking procedure; the loss rate varied among individual compounds. Boiling and steaming significantly reduced AsA content (24.3~66.5%), TP (13.9~54.9%), and antioxidant activity (21.7~60.5%) in red pepper, while stir-frying and roasting slightly reduced AsA content (2.7~25.9%), TP (1.8~4.9%), and antioxidant activity (4.9~17.9%). The highest loss was observed after boiling, followed by steaming, roasting, and stir-frying. Stir-frying and roasting better preserved AsA content, TCC, TP, and antioxidant activity. In conclusion, dry-heat cooking methods such as stir-frying and roasting may be preferred to retain the nutrient compositions and antioxidant properties of red pepper.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.335-338
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• 2007

Five samples (Bakwoonbae, Chungsilbae, Sandolbae, Dolbae, and Chuwhangbae) of Pyrus species differing in their origin of production were analyzed for total phenolic content, vitamin C content, and antioxidant activities. Two antioxidant activities were measured by the free-radical scavenging activity and reducing power method. Total phenolic content of the Chungsilbae extract (20.35 mg/g) was higher than those of other pears. Vitamin C content in five Pyrus species ranged from $420.32\;{\mu}g/g$ in Sandolbae to $659.75\;{\mu}g/g$ in Bakwoonbae. Chungsilbae also had the highest free radical scavenging activity (76.56%) and reducing power (0.35).

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.6
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• pp.519-528
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• 2019

Mitochondrial dysfunction is closely associated with reactive oxygen species (ROS) generation and oxidative stress in cells. On the other hand, modulation of the cellular antioxidant defense system by changes in the mitochondrial DNA (mtDNA) content is largely unknown. To determine the relationship between the cellular mtDNA content and defense system against oxidative stress, this study examined a set of myoblasts containing a depleted or reverted mtDNA content. A change in the cellular mtDNA content modulated the expression of antioxidant enzymes in myoblasts. In particular, the expression and activity of glutathione peroxidase (GPx) and catalase were inversely correlated with the mtDNA content in myoblasts. The depletion of mtDNA decreased both the reduced glutathione (GSH) and oxidized glutathione (GSSG) slightly, whereas the cellular redox status, as assessed by the GSH/GSSG ratio, was similar to that of the control. Interestingly, the steady-state level of the intracellular ROS, which depends on the reciprocal actions between ROS generation and detoxification, was reduced significantly and the lethality induced by $H_2O_2$ was alleviated by mtDNA depletion in myoblasts. Therefore, these results suggest that the ROS homeostasis and antioxidant enzymes are modulated by the cellular mtDNA content and that the increased expression and activity of GPx and catalase through the depletion of mtDNA are closely associated with an alleviation of the oxidative stress in myoblasts.

• Food Science and Preservation
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• v.31 no.2
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• pp.256-266
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• 2024

This study examined the effects of chestnut powder content (2.5%, 5%, 7.5%, and 10%) on the antioxidant activity and quality characteristics of rice muffins. With the increasing chestnut powder content, the total polyphenol content, flavonoid content, antioxidant activity (determined by radical scavenging activity and reducing power), hardness, gumminess, chewiness, and overall acceptability (determined by sensory evaluation) increased, whereas the moisture content, pH, specific volume, and cooking loss decreased. Regarding color, chestnut powder content was negatively correlated with L and b and positively correlated with a. Notably, overall acceptability abruptly decreased to its minimum at 10%. Thus, adding powder at loadings of <7.5% improved the antioxidant activity and acceptability of rice muffins. Our results can be used as preparatory data for developing a rice muffin model.