• ALGAE
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• v.20 no.3
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• pp.251-260
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• 2005

Antioxidative activities of Chlorophyta and Phaeophyta in Jeju Island were measured by superoxide anion ($O_2^{{\cdot}-}$), hydroxyl radical ($HO^{\cdot}$), hydrogen peroxide ($H_2O_2$) and DPPH free radical scavenging assays. Methanolic and aqueous extracts of the seaweeds were prepared at both temperatures, higher (70$^{\circ}C$) and room temperature (20$^{\circ}C$), and screened for the construction of an extract bank from seaweeds in Jeju Island. A variety of extracts showed positive effect against reactive oxygen species (ROS). Especially, Sargassum thunbergii methanolic extract at 70$^{\circ}C$ (70ME, 97.41%), S. fulvellum methanolic extract at 20$^{\circ}C$ (20ME, 84.66%), Codium fragile aqueous extract at 70$^{\circ}C$ (70AE, 96.61%) and S. thunbergii 20ME (97.44%) exhibited the highest scavenging activities against $O_2^{{\cdot}-}$, $HO^{\cdot}$, $H_2O_2$ and DPPH free radicals, respectively. Total phenolic contents also examined but did not show a positive correlation with ROS scavenging abilities (except for a few extracts). These results indicate that further investigation is needed to identify and purify the responsible antioxidative components.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.700-703
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• 2005

Eight edible mushrooms grown in Korea were extracted with ethanol at room temperature for 24 hr. The extracts were investigated for their antioxidant activities as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activities. Among the mushroom extracts evaluated in this study, the ethanolic extracts from Ganoderma lucidum and Pleurotus eryngii showed the greatest potential antioxidant activity, by producing 85 and 88% inhibition in DPPH radical scavenging method and 219 and 165 mg ascorbic acid equivalent antioxidant capacity (AEAC), respectively. Total phenolics and total flavonoids in the ethanolic extracts were determined by spectrophotometric method. Positive correlations were found between total phenolic contents in the extracts and their antioxidant activities, suggesting that phenolic contents in the mushrooms extracts are mainly responsible for their antioxidant activities.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.460-465
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• 2008

The objective of this study was to evaluate the antioxidant properties and sensory qualities of citron peel tea, and to determine the optimum ratio of citron peel powder for its preparation. Yuza peel powders were prepared with citron peel tea at weight 2 and 3 g, respectively. Then, color values(L-value, redness, and yellowness), total phenol content, total antioxidant activity, DPPH radical scavenging activity, and sensory characteristics were measured in the tea samples. The pH of the citron peel tea decreased with increasing preparation temperature. And as the amount of citron peel powder increased, total phenol content, antioxidant capacity, and radical scavenging activity increased. The level of total phenolics in the tea had a higher correlation with total antioxidant capacity($r^2$ = 0.731). Depending on the level of added yuza powder, significant differences(p < 0.05) were shown for aroma, color, and overall acceptability however, there were no significant differences in sourness and bitterness.

• Preventive Nutrition and Food Science
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• v.21 no.1
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• pp.68-72
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• 2016

To examine the possibility of using thiacremonone isolated from high-temperature-high-pressure treated garlic, this study investigated the physiological activities properties. The $IC_{50}$ values of hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radical scavenging activities of thiacremonone were 92.50, 65.05, 12.60, and $81.53{\mu}g/mL$, respectively. On the other hand, the activities of vitamin C were 104.93, 99.43, 42.42, and $122.64{\mu}g/mL$, and the activities of butylated hydroxyanisole were 37.22, 68.45, 22.47, and $40.54{\mu}g/mL$, respectively. The $IC_{50}$ value of ACE inhibition activities of thiacremonone and captoprill were 0.265 and $0.036{\mu}g/mL$, respectively. The $IC_{50}$ value of xanthine oxidase inhibition activities of thiacremonone and allopurinol were 39.430 and $9.346{\mu}g/mL$, respectively. The $IC_{50}$ value of tyrosinase inhibition activities of thiacremonone and kojic acid were 101.931 and $65.648{\mu}g/mL$, respectively.

• Korean Journal of Medicinal Crop Science
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• v.24 no.5
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• pp.351-359
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• 2016

Background: We investigated the optimal aqueous extraction conditions for recovery of high yields of total phenolic compounds from roots of Arctium lappa L. (burdock, Asteraceae), and we compared their antioxidant capacity. Methods and Results: The antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, and oxygen radical absorbance capacity assays. In addition, the major phenolic compounds present in the extracts were determined by high performance liquid chromatography analysis. Our results suggest that the roasted burdock $100^{\circ}C$, 15 min extract exhibited the strongest radical scavenging activity and possessed the highest concentration of phenolic compounds. The polyphenol content of both dried burdock and roasted burdock significantly increased with increase in the extraction temperature and time. Conclusions: These results indicated a relationship between phenolic compound levels in burdock and their free radical scavenging activities. This suggests that phenolic compounds significantly increase the antioxidant potential of burdock extracts.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.258-263
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• 2018

To assess a potential possibility of Deoduck as functional food resources, this study was performed to determine the changes in chemical components and antioxidant activities on Deoduck with various aging conditions; aging temperatures were 60, 70, and $80^{\circ}C$, and aging periods were 5, 10, 15, 30, and 50 days. We determined pH, total acidity, browning index, 5-hydroxymethyl-furfural, total phenolic contents, DPPH and ABTS radical scavenging activities of aged Deoduck. Total acidity of aged samples increased during aging treatment, at higher temperature and longer time. The pH value of aged Deoduck ranged from 4.97 to 3.76. Aged Deoduck at $60^{\circ}C$ decreased slowly than 70 and $80^{\circ}C$, and these results were similar in total acidity. 5-HMF and total phenolic contents increased when increased aging temperature and periods. The DPPH and ABTS radical scavenging activities of Deoduck were ranged from 0.374 to 1.560 mg TEAC eq/g and from 0.302 to 1.745 mg trolox eq/g, respectively.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.445-449
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• 2015

This study was directed to finding an optimum extraction condition of genistein from the S. flavescens with supercritical carbon dioxide as a solvent. In this effort, effects of the extraction conditions including pressure, temperature and a co-solvent on the extraction efficiency were investigated. The aqueous ethanol and methanol solutions were used as co-solvents while the tested operating pressure and temperature ranges were from 200 bar to 300 bar and from 308.15 K to 323.15 K, respectively. The concentration of genistein was determined by means of HPLC equipped with a UV detector. From the results, it was observed that an increase in pressure led to the higher extraction efficiency. Further, methanol showed better performance as a co-slovent than ethanol. The DPPH radical scavenging activities were measured to compare antioxidant activities of S. flavescens extracts.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1387-1390
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• 2008

This study evaluated the effects of heat treatment on antioxidant activity of Rehmannia radix Libosch (RRL). RRL was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid content, and antioxidant activity were investigated. With increased heating temperature and exposure time, total content of polyphenol, flavonoid, as well as antioxidant activity increased. The highest total polyphenol and flavonoid contents were 21.65 and 3.56 mg/g, respectively, these values were occurred after heating for 3 hr at $150^{\circ}C$ (RRL was 5.09 and 0.83 mg/g, respectively). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was highest value of 83.46% after heating for 3hr at $150^{\circ}C$. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity was highest value of 20.43mg ascorbic acid (AA) eq/g after heating for 2 hr at $150^{\circ}C$. There were highly significant differences in the total polyphenol, flavonoid content, and antioxidant activity among heating temperatures and times (p<0.001), with heating temperature having the greater effect.

• Journal of Mushroom
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• v.19 no.1
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• pp.14-22
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• 2021

This study investigated the changes in the antioxidant activity, nitrite scavenging activity, and ��-glucan content of processed raw materials (Pleurotus eryngii, Pleurotus ostreatus, Lentinula edodes, and Flammulina velutipes) brought about by storage at room temperature (20-25℃) and low temperature (4℃). The results indicated that DPPH free radical scavenging activity was the lowest in air-dried and roasted samples that were stored at room temperature, k with the exception of the air-dried samples of P. eryngii and L. edodes. For total polyphenol contents, all roasted samples of the edible mushrooms stored at room and low temperature decreased compared with the samples pre-storage, except for the air-dried samples of P. eryngii, P. ostreatus, and L. edodes. Furthermore, the ferric reducing antioxidant power and reducing power of the air-dried and roasted samples stored at room temperature and low temperature tended to increase compared to that before storage. Moreover, the ��-glucan content in the air-dried and roasted samples stored at room temperature was significantly lower compared to that before storage, as well as to that in the samples stored at low temperature (p<0.05). The results of this study may help predict the degree to which biological activities in processed edible mushrooms change when stored at room temperature and/or low temperature conditions.

• Food Science and Preservation
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• v.13 no.2
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• pp.119-124
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• 2006

This study was conducted to optimize roasting process of Job's tears for utilization as food Optimal condition for masting was investigated with changes in temperature and time by response surface methodology. The qualities of water extract such as browning degree, polyphenol and DPPH radical scavenging ability were affected more by roasting temperature than time. The values increased with temperature and time proportionally. The response variables were more significant with temperature than time and the established polynomial model was suitable (P>0.05) model by Lack-of-Fit analysis. Optimal roasting conditions with the limit of $0.2{\sim}0.3$ browning degree, $2.0{\sim}2.5{\mu}g/mL$ polyphenol, $30{\sim}40%$ scavenging ability and $0{\sim}100$ hue angle were $215^{\circ}C$ and 32 min.