• Journal of Haehwa Medicine
• /
• v.23 no.1
• /
• pp.105-114
• /
• 2014

Objectives : In this study, the antioxidant activities of the 80% ethanol and hot water extracts of Euphorbia supina Rafinesque were investigated. Methods : We measured total phenol contents, flavonoid contents, 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The production of reactive oxygen species was measured in LPS-induced RAW 264.7 cells using flow cytometry system. Results : The content of phenol in the hot water extract was $65.529{\pm}0.462mg/g$ and $126.932{\pm}1.894mg/g$ in the 80% ethanol extract, and that of flavonoid in the hot water extract was $16.063{\pm}0.471mg/g$ and $29.159{\pm}1.963mg/g$ in the ethanol extract. The 80% ethanol extract also showed higher DPPH and ABTS radical scavenging activities ($90.8{\pm}1.0%$ and $92.5{\pm}0.7%$) than the hot water extract ($81.5{\pm}0.5%$ and $91.5{\pm}0.2%$). The production of reactive oxygen species(ROS) was reduced dose-dependently by 80% ethanol and hot water extract at concentration of 1, 10 and $100{\mu}g/m{\ell}$ of RAW 264.7 cells. Conclusion : According to these results, the 80% ethanol extract of Euphorbia supina Rafinesque has a good anti-oxidative effects than the hot water extract. Thus, the 80% ethanol extract of Euphorbia supina Rafinesque may serve as useful natural antioxidants.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.3
• /
• pp.474-482
• /
• 2016

The black raspberry (Rubus coreanus Miquel) contains anthocyanin, tannins, gallotannin, gallic acid, ferulic acid and phenolics. It brightens the eyes and protects the liver and kidneys. It was effective for anti-aging. Thus, the purpose of this study was to inform the excellence of black raspberry and to screen antioxidant activity to ensure the possibility as a functional material. In this study, bioactive compounds in black raspberry were determined. Additionally, black raspberry was extracted by CM (chloroform:methanol, 2:1, v/v), 70% methanol and 70% ethanol, and were investigated and compared in vitro methods. Total phenol and flavonoid contents were measured to compare each different solvents. In addition, DPPH radical scavenging activity and ABTS radical scavenging activity, ferric reducing antioxidant power, reducing power were determined to measure the antioxidant activity. The results were the highest in 70% ethanol extracts, and the higher the concentration showed a significantly higher antioxidant capacity. When observed the relationship between the study, antioxidant activity of black raspberry was supposed to affect by the anthocyanin, phenol and flavonoid contents.

• Applied Chemistry for Engineering
• /
• v.24 no.2
• /
• pp.121-125
• /
• 2013

In this work, we prepared the carbon paper from chopped carbon fibers using a gas diffusion matrix in polymer electrolyte membrane fuel cells by wet processing. The process of making carbon paper using wet processing is consisted of the three steps involving the dispersion of chopped carbon fibers, the preparation of the carbon fiber web, the impregnating of phenol resin. This work was focused on finding the optimal surfactant to make the carbon paper with 2D orientation of carbon fibers by investigating the dispersion state of carbon fibers in different dispersion solutions. Furthermore, the effect of phenol resin and carbon black contents on properties of electric conductivity was analyzed. As a result, it is confirmed that the carbon fiber was well dispersed when using sodium dodecyl sulfate as a surfactant, and the carbon paper with 8 wt% of phenol and 5 wt% of carbon black contents showed the most excellent electrical property.

• The Korean Journal of Food And Nutrition
• /
• v.33 no.1
• /
• pp.64-73
• /
• 2020

The purpose of this study was to investigate the antioxidant activity and β-glucan content of extracts extracted by varying the temperature at 30, 55 and 80℃ after hot air drying or freeze drying of Pleurotus ostreatus and Pleurotus eryngii. For the analysis antioxidant activity of each mushroom, β-glucan, total phenol, flavonoid contents, and DPPH·ABTS⁺·Nitrite assay were measured. Also, the β-glucan content, total flavonoid content and ABTS⁺ scavenging activity increased with freeze drying rather than hot air drying, and increased with increasing extraction temperature in both mushrooms. However, the total phenol and nitrite scavenging activity increased with hot air drying rather than freeze drying, and decreased with increasing temperature in both mushrooms. DPPH scavenging activity was not significant in both mushrooms, but decreased with increasing extraction temperature. Pearson's correlations between total flavonoid content and antioxidant activities were r=0.719~0.753 (p<0.01). As a result, the β-glucan content, total flavonoid content, and ABTS radical cation scavenging activity were highest during freeze drying and extraction at 80℃. And the highest total phenol content, DPPH radical scavenging activity and nitrite scavenging activity were obtained during hot air drying and extraction at 30℃.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.325-331
• /
• 2008

The propose of this study was to investigate the antioxidant activity of 80% ethanol extracts and various solvent fractions of dandelion (Taraxacmn officinale) leaves and roots, Total phenolics and phenolic acid contents were also examined. The total phenol content of leaves and roots were $7.9{\pm}0.4%$ and $9.4{\pm}0.3%$ respectively. Eight phenolic acids were separated by GC, among which caffeic acid (113.7 mg%)and m-coumaric acid (152.6 mg) were the dominant phenolic acids in leaves and roots, respectively. Amongst solvent functions of leaves and roots, the ethyl acetate fraction showed the strongest radical scavenging activity. A strong correlation was found between total phenol content and electron-donating ability, and ABTS radical scavenging activity showed a similar trend as electron-donating ability. Hydroxyl-radical-scavenging activity and lipid peroxidation were significantly higher in the ethyl acetate fraction than other factions. In particular, the SOD-like activity was highest (43.6%) in the ethyl acetate fraction of dandelion leaves, and was higher than that of trolox. Thus, the ethyl acetate fraction of dandelion leaves exhibited significant phenol content, antioxidant activity, and free-radical-scavenging effects.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3567-3572
• /
• 2010

Black pine barks from the southern region of Korea were extracted using pressurized hot water and the water soluble extracts were then separated in a stepwise fashion using a variety of solvents, column chromatography (CC), thin layer chromatography (TLC), and high pressure liquid chromatography (HPLC). The antioxidant activities of each fraction and the active compounds were determined based on the radical scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), reductive potential of ferric ion, and total phenol contents. A DPPH test showed that the half maximal effective concentration ($EC_{50}$ value : $6.59{\pm}0.31\;{\mu}g/mL$) of the ethyl acetate fraction (ca. 0.67%) was almost the same as that of the control compounds and inversely proportional to the value of the total phenol contents. The cell viability of the water extracts was confirmed by methyl thiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT) with enzyme linked immune sorbent assay (ELISA). Catechin, epicatechin, quercetin and ferulic acid were isolated from the ethyl acetate fraction as active compounds and identified by nuclear magnetic resonance. The antioxidant activity as value of DPPH of each of the separated compounds was lower than the ethyl acetate fraction, and ferulic acid was the lowest among these compounds.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.4
• /
• pp.685-692
• /
• 2013

Yuza (Citrus junos) has 3 varieties with variable physiochemical properties. This study analyzed these volatile compounds and physiochemical properties according to variety. Three Yuza varieties, native (Citrus junos I), improved I (Citrus junos I+Poncirus trifoliata), improved II (Citrus junos I+C. junos II) were used. The native Yuza weighted more than the improved varieties, but the peel ratio (weight of peel versus pulp) was high in improved one. Protein and ash contents were high in Improved I than native one. Native had 29.6mg% vit. C in pulp and improved I had 57.7mg% vit. C in peel. Free sugar was mainly fructose, and the main organic acid was citric acid in Yuza. Improved I Yuza had high free sugar contents, and the organic acid levels were high in improved II Yuza. Linoleic acid was the most prevalent fatty acid in Yuza; it was distributed in peel or pulp. The most common volatile flavor component was dl-limonene (64~70%); improved II Yuza showed significantly higher contents of dl-limonen and ${\gamma}$-terpinen. Total phenol level of Yuza was identical in all types, but peels had 2.5 times more than pulps.

• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.5
• /
• pp.597-604
• /
• 2013

This study was conducted to investigate the effect of mulberry leaf powder on the antioxidant activity and the quality characteristics of maejakgwa (a Korean traditional cookie). Maejakgwa was prepared with different amounts of mulberry leaf powder (in ratios of 0, 3, 6, 9 and 12% to the flour quantity). The antioxidant activity was estimated by DPPH free radical scavenging activity and the total phenol content in mulberry leaf powder and maejakgwa. For analyzing the quality characteristics, bulk density and the pH of the dough, moisture contents, color, texture profile analysis and sensory evaluations were measured. The total phenol contents, DPPH free radical scavenging activity, bulk density of the batter and the a values of maejakgwa significantly increased with increasing mulberry leaf powder, whereas the pH of the batter, L values and b values of the maejakgwa significantly decreased with increasing mulberry leaf powder content. Finally, the results of the acceptance test indicated that maejakgwa containing 6% mulberry leaf powder had the highest scores. From these results, we suggest that mulberry leaf is a good ingredient for increasing consumer acceptability as well as the functionality of maejakgwa.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.1
• /
• pp.62-69
• /
• 2014

Jungkwa is a traditional Korean dessert preserved in honey or sucrose. This study was carried out to investigate the antioxidant activities and quality characteristics of Rehmannia glutinosa Jungkwa (RJ). RJ was prepared after six repeated cycles of boiling-cooling. After blanching fresh Rehmannia glutinosa (600 g) for 5 min at $100^{\circ}C$, Rehmannia glutinosa was boiled in sucrose syrup (sucrose 720 g in water 600 g) for 60 min and then cooled for 24 hr. Moisture, pH and color values of lightness, redness and yellowness in the Hunter color system of Jungkwa decreased as the number of boiling-cooling cycles increased, whereas acidity, $^{\circ}Brix$ and reducing sugar contents of syrup increased. Total phenol content increased in by the 6th boiling-cooling cycle. Antioxidant activities, including DPPH and hydroxyl radical scavenging activities, increased in RJ by the 6th boiling-cooling cycle. Based on these results, the antioxidant activities of Rehmannia radix Jungkwa was improved according to an increasing number of boiling-cooling cycles due to increased total phenol contents.

• Korean journal of food and cookery science
• /
• v.17 no.5
• /
• pp.456-463
• /
• 2001

The proximate composition of 3 kinds of Umbelliferaeceae Wild Plants (Angelica gigas NAKAI., Ostericum sieboldii NAKAI. and Coriandrum sativum LINNAEUS) were analyzed and used for making pork sausages as a functional ingredient. In the proximate composition, crude protein content was the highest in Ostericum sieboldii, 37.87%, and crude lipid and crude ash contents were the highest in Coriandrum sativum. Vitamin C was contained in Angelica gigas at 0.30mg%. but was not detected in Ostericum sieboldii and Coriandrum sativum. $\beta$-carotene content in Angelica gigas was the highest at 19.96%, but selenium was not detected in any of them. Total phenol content in Coriandrum sativum was the highest as 1107.43mg%. TBA and VBN values of all sausages with wild plants increased gradually during four-week-storage and were lower than those of control. Coriandrum sativum-added sausage had the lowest TBA as well as VBN valuew. During the four-week-storage at 4$\^{C}$, TBA value and VBN value were in the very safe range at all sample. Total phenol contents in sausages appeared to have more antioxidative activity than vitamin C, $\beta$-carotene and selenium, and consequently decreased the TBA values of sausages.