• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.6-15
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• 1998

A total of forty five-ply, 30- by 30-cm lauan and larch plywood sheets were manufactured in the laboratory using commercial urea and phenol resin adhesives; half of these sheets were treated with fresh concrete. Each sheet was carbonized for 2, 4, and 6hours at $400^{\circ}C$, $600^{\circ}C$, and $750^{\circ}C$, respectively, and their physical properties were measured. The yie1d of charcoal decreased as carbonization temperature and time increased. Charcoal yield was greater in plywood than in veneer, and slightly greater in plywood treated with concrete compared to untreated plywood. Plywood manufactured with phenol resin adhesive had higher pH, higher equilibrium moisture content (EMC), and greater adsorption of methylene-blue dye compared to plywood manufactured with urea resin. For concrete-treated plywood, pH was greater than 10 even when the sheets were carbonized for 2hours at $400^{\circ}C$. Although the EMC of the phenol resin plywood was higher than that of the urea resin plywood, EMC of the phenol resin was lower than that of the urea resin. The larch phenol resin plywood that was carbonized for 6 hours at $750^{\circ}C$ adsorbed more methylene-blue than did the commercia1 wood-based activated charcoal as a result of total pore volume and surface area.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.84-90
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• 2000

This study was conducted to determine the acid and phenol compounds in smoke total particulate matter(TPM) by the different tobacco variety, and grade of tobacco leaves. Sixteen kinds of tobacco leaves which were flue-curd, burley, orient, reconstituted tobacco, expanded stem, and expanded cut tobacco, were selected for this study. After collecting a TPM by using smoking machine, the concentration of TPM components was analyzed by GC. Acid components of TPM of mainstream smoke were different from the variety and grade. The order of the highest concentration of acid compounds in TPM was flue-cured > orient> burley> expanded cut tobacco> reconstituted tobacco> expanded stem. Though lactic acid and glycolic acid concentrations in flue-cured tobacco were twice higher than those in burley tobacco, the contents of 2-furoic acid and 3,4-dihydroxy butanoic acid in burley tobacco were higher than those in flue-cured tobacco. The content of phenolic compounds in the high grade and thick leaves was higher than that in other tobacco leaves. Phenol and catechol compounds in burley CD3W-2 revealed the least value in concentration among the samples tested. Pyrocatechol and hydroquinone concentrations in flue-cured tobacco were 2-3 times higher than those in burley and orient tobacco.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1151-1156
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• 2005

The comparison on antioxidative activity of 13 kinds of vegetables that showed efficient oxygen radical absorbance capacity was carried out under in uitro and cellular model using LLC-$ PK_{1}$ renal epithelial cell, and also the total Phenol contents were analyzed. Beets, eggplant, and kale exerted the strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect and also these vegetables showed high contents of total phenol, indicating the positive relationship between DPPH radical scavenging effect and total phenol content. In addition, the treatment of 1 mM 2,2'-azobis (2-amidinopropane) dihydrochloride for 24 hrs to LLC-$PK_{1}$ cell susceptible to oxidative stress led to the decline of cell viability to 68.1$\%$, whereas the cellular oxidative damage was ameliorated by vegetables, especially eggplant and cauliflower, resulting in the elevation of cell viability to higher than 90$\%$ at the concentration of 5 $\mu$g/mL. This study suggests that 13 kinds of vegetables exert antioxidative activity under in uitro and cellular oxidative damage model, in particular among them eggplant showed the most effective antioxidative activity with higher total phenol content.

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.599-606
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• 2018

Purpose: Various plants, herbal medicines, and marine foodstuffs have been used in kimchi preparation to improve its overall quality. Teff, which is rich in minerals and starches, facilitates stable blood glucose levels and is well-suited for use in gluten-free products; hence, it can be used to reinforce the mineral composition of kimchi. In this study, we probed the antioxidant activities of hydrolysates prepared by treatment of brown teff with three proteases under different conditions. Methods: The mineral composition of brown teff was determined by inductively coupled plasma spectrophotometry-mass spectrometry, and we established optimal hydrolysis conditions by determining the total phenol and flavonoid contents of teff hydrolysates obtained using three different proteases (protamax, flavourzyme, and alcalase), two different protease concentrations (1 and 3 wt%), and three different incubation times (1, 2, and 4 h). The antioxidant activity of the hydrolysates was further investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, total antioxidant capacity (TAC), and ferrous reducing antioxidant power (FRAP) assays. Results: Brown teff was rich in I, K, Mg, and Ca, and the highest total phenol content ($24.16{\mu}g/mL$), total flavonoid content ($69.08{\mu}g/mL$), and TAC were obtained for 1 wt% protamax treatment. However, the highest DPPH scavenging activity and FRAP values were observed for hydrolysates produced by alcalase and flavourzyme treatments, respectively. Conclusion: Treatment of brown teff with proteases affords hydrolysates with significantly increased antioxidant activities and high total phenol and flavonoid contents, and these antioxidant activities of teff hydrolysates have the potential to enhance the quality and functionality of kimchi in future applications.

• 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.

• Food Science and Preservation
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• v.11 no.4
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• pp.455-460
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• 2004

This study was conducted to determine the yield, free radical scavengering effect and total phenol contents of various solvent fractions on the crude and defatted grape seed extract during storage. The optimal condition for the extraction yield, free radical scavengering effect and total phenol contents was $90\%$ ethanol for 6 hour at $70^{\circ}C$. The extraction yield for crude and defatted grape seed at optimal condition was $8.9\%\;and\;9.16\%$, respectively. Also, the strongest free radical scavengering effect with $41.52\;{\mu}g/mL$ was observed in $95\%$ ethanol of defatted grape seed extracted for 6 hour at $70^{\circ}C$. Similar result was observed in total phenol contents of defatted grape seed. The ethyl acetate fraction obtained from ethanol extract of defatted grape seed showed the strongest RC50($12.35\;{\mu}g/mL$) compared to other organic fractions. Free radical scavengering effect of crude and defatted grape seed extracts treated with alkali condition(pH 10) was reduced compared to that of acidic condition(pH 2) during storage far 1 month at $50^{\circ}C$. Overall, more stronger free radical scavengering effect and higher total phenol contents in defatted grape seed extracts was observed than that of crude grape seed.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.490-495
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• 2012

The catalytic effect induced by activated carbon (AC) was evaluated during the phenol treatment using an ozone/AC ($O_{3}/AC$) process. In the case of the addition of AC to the ozone only process, the decomposition efficiency of dissolved ozone and phenol increased with increasing the amount of AC input. It was that the OH radical generated from the decomposition of dissolved ozone by AC had an effect on the removal of phenol. It was shown as the catalytic effect of AC ([$\Delta$phenol]/$[{\Delta}O_{3}]_{AC}$) in this study. The maximum catalytic effect was approximately 2.13 under 10~40 g/L of AC input. It approached to the maximum catalytic effect after 40 min of reaction with 10 and 20 g/L of AC input, while the reaction time reached to the maximum catalytic effect under 30 and 40 g/L of AC input was approximately 20 min. Moreover, the removal ratios of total organic carbon (TOC) for ozone only process and ozone/AC process were 0.23 and 0.63 respectively.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.418-426
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• 2015

Total phenol contents, total flavonoid contents and antioxidant activity of 70% methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts from onion (Allium cepa L.) peels were studied. The $IC_{50}$ values of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity in 70% ethanol extract were remained to be lowest followed by 70% methanol extract and CM extract. And the total phenol content ($113.56{\pm}0.86mg\;CAE/g$), total flavonoid content (49.63 mg QE/g) and ferric reducing antioxidant power value were also found to be the highest. In contrast, 70% methanol extract possessed the strongest antioxidant activity by ${\beta}$-carotene bleaching assay. CM extract displayed the lowest antioxidant activity compared with other extracts. Onion peels exhibited strong antioxidant activity and abundant phytochemicals, which could be used in a various food products to add phytochemicals and promote good health.

• Journal of Life Science
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• v.23 no.10
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• pp.1273-1279
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• 2013

Aromatic hydrocarbons, such as phenol, have been detected frequently in wastewater, soil, and groundwater because of the extensive use of oil products. Bacterial strains (56 isolates) that degraded phenol were isolated from soil and industrial wastewater contaminated with hydrocarbons. GN13, which showed the best cell growth and phenol degradation, was selected for further analysis. The GN13 isolate was identified as Neisseria sp. based on the results of morphological, physiological, and biochemical taxonomic analyses and designated as Neisseria sp. GN13. The optimum temperature and pH for phenol removal of Neisseria sp. GN13 was $32^{\circ}C$ and 7.0, respectively. The highest cell growth occurred after cultivation for 30 hours in a jar fermentor using optimized medium containing 1,000 mg/l of phenol as the sole carbon source. Phenol was not detected after 27 hours of cultivation. Based on the analysis of catechol dioxygenase, it seemed that catechol was degraded through the meta- and ortho-cleavage pathway. Analysis of the biodegradation of phenol by Neisseria sp. GN13 in artificial wastewater containing phenol showed that the removal rate of phenol was 97% during incubation of 30 hours. The removal rate of total organic carbon (TOC) by Neisseria sp. GN13 and activated sludge was 83% and 78%, respectively. The COD removal rate by Neisseria sp. GN13 from petrochemical wastewater was about 1.3 times higher than that of a control containing only activated sludge.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.186-194
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• 2016

Consumption of fruits and vegetables has been conducted to be effective in the prevention of chronic diseases. In this study, 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v) were used as solvents in the extraction of apple peels. The total phenol content, total flavonoid content and antioxidant activity of various extracts were investigated using in vitro assays. The extract obtained by 70% methanol showed the highest total phenol content ($20.87{\pm}0.17mgCAE/g$), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity and ferric reducing antioxidant power. However, 70% ethanol extract possessed the strongest antioxidant activity assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ${\beta}$-carotene bleaching method. And CM extract was found to show the highest total flavonoid content with the value of $9.26{\pm}0.06mgQE/g$. These results indicated that apple peels can be used in dietary applications with a potential to reduce oxidative stress.