• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.677-682
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• 2011

This study explores the antioxidant activities of solvent extracts from Rhus verniciflua, and the results were as follows. Total phenolic compound and flavonoid contents of Rhus verniciflua were $4.32{\pm}0.17$ mg/100 g and $0.16{\pm}0.02$ mg/100 g, respectively. Electron-donating abilities of solvent extracts from Rhus verniciflua proportionally increased with concentration, and ethyl acetate extract ($95.4{\pm}0.4%$) showed higher activity than that of BHT ($93.3{\pm}1.7%$) at a concentration of 1,000 ${\mu}L$/mL. Reducing power of the solvent extracts from Rhus verniciflua was the highest in ethyl acetate extract ($2.45{\pm}0.03$) at a concentration of 1,000 ${\mu}L$/mL. Nitrite scavenging ability of the solvent extracts from Rhus verniciflua (pH 1.2, 1,000 ${\mu}L$/mL) was the highest in ethyl acetate extract ($95.5{\pm}0.7%$). Therefore, ethyl acetate extract from Rhus verniciflua has similar antioxidant activity as that of BHT.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.657-666
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• 2012

The purpose of this study was to improve the quality of Korean traditional sauce products by producing short-term green gochujang with cheongyang pepper powder. To determine its antioxidant compounds and activities, we examined vitamin C, capsaicinoid, total phenolic, and total flavonoid contents, as well as electron-donating, SOD-like, ferrous ion-chelating, and nitrite-scavenging activities. Vitamin C content of short-term green gochujang was higher in CON-M than in the sample, whereas capsaicinoid content increased as the amount of cheongyang pepper powder increased. Total phenolic content, total flavonoid content, electron-donating activity, and nitrite-scavenging activity were higher in the sample than in CON-M, and the contents increased as the amount of meju powder increased. Green gochujang containing the highest amount of cheongyang pepper powder showed the highest SOD-like, and ferrous-ion chelating activities as well as superior nutrient contents, compared to red gochujang.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.836-840
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• 2005

Extraction characteristics of Bonus species of Brassica oleracea var. capita and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 44.07% was obtained at ratio of solvent to sample of 27.94 mL/g, ethanol concentration of 24.35%, and extraction temperature of $55.21^{\circ}C$. At ratio of solvent to sample, ethanol concentration, and extraction temperature of 21.11 mL/g, 58.53%, and $68.83^{\circ}C$, respectively, maximum electron-donating ability was 48.44%. Maximum inhibitory effect on tyrosinase was 68.94% at ratio of solvent to sample, ethanol concentration, and extraction temperature of 24.08 mL/g, 10.49%, and $78.71^{\circ}C$, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 24.78% at ratio of solvent to sample of 22.66 mL/g, ethanol concentration of 45.69%, and extraction temperature of $93.81^{\circ}C$. Based on superimposition of four-dimensional RSM with respect to extraction yield, electron-donating ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were ratio of solvent to sample of 20-30 mL/g, ethanol concentration of 35-65%, and extraction temperature of $50-80^{\circ}C$.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.715-721
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• 2005

Antioxidant activities of grape seeds extracted with various solvents were evaluated by measuring total phenol and flavanol contents, thiobarbituric acid reactive substances (TBARS) following lipid peroxidation, 2-deoxyribose degradation, SOD-like activity, 2,2'-azino-bis(3-ethylbenzthizaoline-6-sulfonic acid (ABTS) radical-scavenging ability, and electron-donating ability using 1,1-diphenyl-2-pycryl hydrazil (DPPH) method. Total phenol and flavanol contents of mixted-solvent extracts were higher than those of single-solvent extracts, with the mixing ratio of 17:3 (ethyl acetate: water) (EW) showed the highest contents. Antioxidant activities (%) of TBARS following phosphatidylcholine peroxidation were 14, 45, 45, 7, 4, 25, 21, 23, and 20% for ascorbic acid (AA), butylated hyroxytoluene (BHT), quercetin (Q), acetone extract (AT), ethyl acetate (EA) extract, methanol (MeOH) extract, 4:1 (EA) extract, 9:1 (EW)-extract, and 17:3 EW extract, respectively. Antioxidant activities for 2-deoxyribose degradation were 5, 80, 87, 78, 56, 73, 64, 60, and 75% in AA, BHT, Q, AT, EA, MeOH extract, 4:1 EW extract, 9:1 EW extract, and 17:3 EW extract, respectively. MeOH grape seed extract showed distinctly stronger electron-donating activity than other solvent extracts.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1476-1480
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• 2009

Antioxidant activities of mulberry leaf extracted with different concentrations of EtOH were investigated. Total phenolic content and electron donating abilities of extract from 70% EtOH were the highest. Extracts obtained from EtOH-water mixture were shown to be significantly higher superoxide dismutase (SOD)-like activities than other treatment (p<0.05). Angiotensin-converting enzyme (ACE) inhibition was the greatest at 50% EtOH concentration (p<0.05). The extracts from 30-70% EtOH exhibited higher ferric reducing ability of plasma (FRAP) value than rest of the concentration (p<0.05). In case of nitrite scavenging activity, much higher scavenging activities were observed when the extraction was performed with EtOH or EtOH-water mixture (p<0.05). The results indicate that concentration of EtOH as extraction solvents can affect the antioxidant activity of mulberry leaf, which may provide useful information on the optimal solvent conditions for the extraction.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.698-706
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• 1996

Dehydrogenation of methanol to produce formaldehyde was carried out over various silica-alumina catalysts doped with alkali metals in a continuous flow system. The reaction was rather dependent on Lewis acid than Br${\ddot{o}}$nsted acid suggesting that dehydrogenation of methanol was an electronic reaction. The Br${\ddot{o}}$nsted acid sites on silica-alumina were neutralized by doping with alkali metals, and the neutralization effect of Br${\ddot{o}}$nsted acid was dependent on the electron-donating capacity of the dopant metals. Activation energy for dehydrogenation of methanol decreased when Br${\ddot{o}}$nsted acid was neutralized by doping with K.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.2
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• pp.250-256
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• 2013

We investigated noodles supplemented with turmeric, purple sweet potato, or seaweed (Hizikia fusiforme) for their functional properties, including total phenol, flavonoid contents, electron donating abilities, and nitrite scavenging abilities. The percentage of total phenolic compounds in turmeric, purple sweet potato, and seaweed noodles were 2.40, 2.47, and 1.27%, respectively, whereas the percentage of total flavonoid contents were 0.55, 0.92, 0.74%, respectively. Results showed that purple sweet potato noodles had the highest amount of phenolic compounds and flavonoids compared to the other types of noodles. The electron donating abilities of the turmeric, purple sweet potato, and seaweed noodles were 4.72, 4.11, and 3.11 at 1,000 ppm respectively. The nitrite scavenging abilities of the turmeric, purple sweet potato, and seaweed noodles were 75.93, 79.81, and 73.51% at pH 1.2, respectively. Purple sweet potato noodles had the highest nitrite scavenging abilities, with an effect better than BHT and ascorbic acid. The ferrous ion chelating effect of turmeric, purple sweet potato, and seaweed noodles were 12.17, 13.63, and 42.12%. All of the experimental results showed good anti-oxidative activity; thus rice noodles supplemented with turmeric, purple sweet potato, or seaweed, have good functional effects for human beings.

• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.17-26
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• 2005

This study was conducted to investigate the usefulness of a hot water extract of licorice root as a source for production of healthy food. The electron donating capacity of the hot water extract of licorice root was very strong. This activity decreased by $6.9\%$ after keeping it in 5 days of cold storage, but it was not significantly different. Ten types of licorice jellies were prepared, using agar, agar-pectin, agar-cellulose, 2 different proportions of agar-pectin-cellulose as a gelling agent, and 2 levels of sugar. Among the 5 jellies containing $10\%$ sugar, the elasticity and overall acceptance of the agar jelly obtained the highest sensory score, but the color and flavor were not affected by the type of gelling agents. As the sugar concentration increased to $15\%$, the elasticity of the agar jelly was also evaluated as being the best one among the 5 jellies, but the overall acceptance was not significantly different from the others.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.717-723
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• 2009

Thermal degradation characteristics of sucrose was investigated. A 20% sucrose solution was heated to temperatures of $110-150^{\circ}C$ for 1-5 hr. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugars, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) of the heated sucrose solutions were evaluated. With increasing temperatures and times, the L-, a-, and b-values decreased; however, total color difference (${\Delta}E_{ab}$) increased. The pH and sucrose contents decreased, and fructose and glucose contents increased with increasing heating temperature and time. Organic acids, such as formic acid, lactic acid, and levulinic acid, and HMF contents increased with increasing heating temperatures and times. EDA (%) and the AEAC of the heated sucrose solutions increased with increasing heating temperature and time. The heated sucrose solution was more effective than unheated sucrose solution, having higher EDA (90 fold), and AEAC (13 fold).