• Journal of Forest and Environmental Science
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• v.21 no.1
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• pp.16-23
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• 2005

The leaves of Paulownia Coreana Uyeki were collected, extracted with acetone-$H_2O$(7:3, v/v), fractionated with n-hexane, methylene chloride and ethylacetate, and freeze dried to give some dark brown powder. The ethylacetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analysis such as NMR and MS including TLC were performed to characterize the structures of the isolated compounds. From the ethylacetate fraction, five flavonoides and three phenolic acids were isolated and determined.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.36-43
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• 2011

Plant biomass has been proposed as an alternative source of petroleum-based chemical compounds. Especially, aromatic chemical compounds can be obtained from lignin by depolymerization processes because the lignin consist of complex aromatic materials. In this study, kraft lignin, the largest emitted substance among several kinds of lignin in Korea, was used as a starting material and was characterized by solid-state $^{13}C$-Muclear Magnetic Resonance($^{13}C$-NMR), Fourier Transform Infrared Spectroscopy(FT-IR), Elemental Analysis(EA). The depolymerization of kraft lignin was studied at water-phenol mixture solvent in near critical region and the experiments were conducted using a batch type reactor. The effects of water-to-phenol ratio and reaction temperature($300-400^{\circ}C$) were investigated to determine the optimum operating conditions. Additionally, the effects of formic acid as a hydrogen-donor solvent instead of $H_2$ gas were examined. The chemical species and quantities in the liquid products were analyzed using gas chromatography-mass spectroscopy(GC-MS), and solid residues(char) were analyzed using FT-IR. GC-MS analysis confirmed that the aromatic chemicals such as anisole, o-cresol(2-methylphenol), p-cresol(4-methylphenol), 2-ethylphenol, 4-ethylphenol, dibenzofuran, 3-methyl cabazole and xanthene were produced when phenol was added in the water as a co-solvent.

• Food Science and Preservation
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• v.12 no.5
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• pp.470-475
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• 2005

Antimicrobial activities of pyroligneous liquor were investigated by determining Minimal Inhibitory Concentration (MIC). The solvent extracts of pyroligneous liquor, which were extracted by using solvents with different polarities such as hexane, ethylacetate, or butanol. The activities were examined by disc diffusion method using MIC against 7 food poisoning microbe type strains. Antimicrobial activities were shown in hexane, ethylacetate, butanol, and aqueous fractions of pyroligneous liquor. Among the four fractions, ethylacetate fraction showed the highest inhibitory effect on the microorganism such as Shigella sonnei, and Yersinia enterocolitica at the concentration of 2.0 mg/disc. The purified P-1 and P-2 fractions isolated by silica gel column chromatography from ethylacetate fraction of pyroligneous liquor had the highest antimicrobial activity. The total phenolic compounds content in ethylacetate, hexane, butanol, and aqueous fraction was 488.3 mg/g, 403.8 mg/g, 83.6mg/g, and 74.5 mg/g, respectively. Taken together, these results suggest that the ethyl acetate fraction could be suitable for the development of isolation and identification of antimicrobial compound from pyroligneous liquor, resulting from the above antimicrobial activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.175-180
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• 2005

This study was carried out to determine total contents of phenol and flavonoid in common and tartary buckwheat for the purpose of developing new kind of functional food with buckwheat materials. Total content of phenol and flavonoid in seeds of tartary buckwheat were higher than that of common buckwheat. It showed same tendency in groats and hulls. Total content of phenol and flavonoid in groats showed higher than hulls in tartary buckwheat while those of hulls was a little higher than groats in common buckwheat seed. Rutin content in common buckwheat was higher in odor of the hulls (25.2 mg/100 g)>dehulled seed(19.8 mg/100 g)>groats (12.8mg/100 g). But tartary buckwheat was higher in oder of the groats(2042.1 mg/100 g)>dehulled seed (1375.8 mg/100 g)>hulls(138.7 mg/100 g). Flavanol content in dehulled seeds of the tartary and common buckwheat did not show the difference. However, flavanol contents in leaf, stem and spouts of tartary buckwheat were respectively higher than in those of common. Among the flavanols, catechin content was highest in all plant parts of their buckwheat and also was higher in odor of epicatechin>epicatechingallate. However, epicatechingallate content in sprouts of both buckwheat species was about 30-40 times higher than seeds.

• Food Science and Preservation
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• v.20 no.5
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• pp.608-613
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• 2013

The physicochemical characteristics and antioxidant capacities of 15 red wines (Cabernet Sauvignon) from the US (5) and Chile (10) were investigated. The contents of soluble solid, reducing sugar, titratable acidity, and $SO_2$ were measured. Antioxidant capacities were examined by DPPH, ORAC assay, and total phenolic contents. In addition, polyphenols composition were analyzed by HPLC. The contents of soluble solid, reducing sugar, and acidities were 7.03~8.6 $^{\circ}Brix$, 2.7~6.7 g/L, and 0.7~0.8%, respectively, and showed no differences between wines from the two countries (p<0.05). The $SO_2$ content of Chile wines was 50% higher than that of US wines (p<0.05). Antioxidant activities by DPPH assay ranged 5.58~9.80 mM and 6.77~9.48 mM in the US and Chile wines, respectively. The ORAC values of the US and Chile wines ranged 2.17~18.08 mM and 4.55~33.77 mM, respectively. The total phenolic content ranged from 1,315 to 2,651 mg/L among the US red wines, and from 1,653 to 2,493 mg/L among Chile red wines. Gallic acid, catechin, syringic acid, p-coumaric acid, quercetin, and kaempferol were identified by HPLC. The polyphenol contents of the Chile red wines were higher than those of the US red wines(p<0.05). There were no differences in the physicochemical characteristics and the antioxidant capacities of the wines from US and Chile, but only in their $SO_2$ and polyphenol contents (p<0.05).

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.777-787
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• 2016

The purpose of this research was the optimization of Cirsium setidens blanched at various conditions by response surface methodology. Conducted to investigate the change of Cirsium setidens DPPH radical scavenging activity, total phenolic compounds and flavonoids during the blanching processes. With two parameters such as blanching time and temperature, response surface methodology and central composite design was used to study the combined effect of blanching time (70 to 170 seconds) and blanching temperature (70 to $99^{\circ}C$). The changes of DPPH radical scavenging activity, phenolic compounds, and flavonoids on blanching process conditions such as temperature and time were evaluated. After blanching, total phenolic compound was determined from 13.00 to 35.48 mg/ml. total flavonoids was determined from 2.31 to 8.38 mg/ml. DPPH radical scavenging activity was determined from 42.10 to 67.14 %. The optimum conditions were determined to be blanching temperature of $85^{\circ}C$ and blanching time of 150 sec.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.119-124
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• 2020

Populus Tomentiglandulosa (PT) is known for pharmacological effects against ischemia-injury and immune activity. This study aimed to investigate the nutritional components, total phenol and flavonoid contents, antioxidant activities of PT extract. Among the mineral contents, the K content (907.5 mg/100 g) was the highest in the PT extract. Vitamins C (6.1 mg/100 g) and nicotinic acid (3.1 mg/100 g) were also found in high amounts. Fructose (2.2%) and glucose (1.6%) were found as free sugars in the PT extract. The total phenolic and flavonoid contents of PT extract were 115.4±0.85 mg GAE/g and 20.9±1.14 mg QE/g, respectively. Results of HPLC analysis of PT extract identified catechin (9.1±0.27 mg/g), caffeic acid (4.1±0.57 mg/g), p-coumaric acid (2.1±0.49 mg/g), chlorogenic acid (1.6±1.86 mg/g), and gallic acid (1.4±0.35 mg/g), respectively. These results suggest that the PT extract possesses high nutritional component and antioxidant properties, which can be used as functional bioresources.

• Korean Journal of Plant Resources
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• v.27 no.2
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• pp.111-118
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• 2014

Contents of phenolics, flavonoids, and catechins, and antioxidant activity were investigated in the ethanol extracts of three different flower species, Magnolia denudata, Prunus mume, Carthamus tinctorius. Total phenolics were more present in M. denudata than P. mume or C. tinctorius, ranging from 72.6 to 118.0 mg/kg (p < 0.05). Total flavonoids level had same tendency to total phenolics content, showing highest amount (25.1 mg/kg) in M. denudata. The antioxidant activity of the methanol extracts from all the flowers dose-dependently increased. DPPH free radical scavenging activity at 250 mg/kgwas higher in M. denudata and P. mume by 93.0 and 92.6%, respectively, than C. tinctorius by 23.0% (p < 0.05). Total catechins content including 6 compounds was higher in M. denudate (9,425.5 mg/kg) than that in P. mume or C. tinctorius (3,407.8 or 190.6 mg/kg). However, P. mume extracts showed highest amount in caffeine as well as vitamine C. DPPH radical scavenging activity in three different flowers was highly correlated with contents of total phenolics ($r^2=0.7994$), total flavonoids ($r^2=0.9131$), and total catechins ($r^2=0.5929$), and their content and activities were different depending on species.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.299-305
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• 2015

The Folin-Denis assay using the Folin-Ciocalteu (F-C) reagent has been commonly used for analyzing the total phenolic compound content in various food products. In the present study, the effects of proteins on the reactivity of the F-C reagent with different phenolic compounds were investigated. Bovine serum albumin (BSA) or skim milk proteins showed a concentration-dependent increase in color response in the Folin-Denis assay; these proteins decreased the color response of most phenolic compounds tested. The reactivity of phenolic compounds was significantly less pronounced in the presence of BSA and this interference was greater at higher concentrations of phenolic compounds. The reactivity of phenolic compounds with the F-C reagent was reduced significantly by their oxidation; the reaction of the oxidized products with the F-C reagent was more severely affected by BSA. The interfering effects in the Folin-Denis assay might be attributable to binding interactions of phenolic compounds with proteins.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.409-417
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• 2012

This study was conducted to determine the variation of phenolic compounds in the leaf and stem of 131 accessions of Lycium chinesis Miller. The levels of total phenolic compounds in the leaf of L. chinesis ranged between 8.8 to $14.9mg\;g^{-1}$ and among them 60% of the accessions belong between 11.6 and $13.5mg\;g^{-1}$ for the content of phenolic compounds in the leaf. The accession CB03286-89 contained the highest total phenolic compounds among the accessions tested, which was 1.7-fold higher than that of the lowest content accession CBP03310-250. In the stem, the total phenolic compound of 131 accessions of L. chinesis ranged from 6.8 to $12.4mg\;g^{-1}$, showing slightly lower level than that in the leaf. The content of (+)catechin was highest in the leaf and stem of accession CB03286-89 and Japan No.1, respectively. Myricetin was detected in the leaf of seven accessions (i.e. Geumsan jaerae, Japan No.1, China collection No.1, CL32-13, CB04329-13, China collection No.12 and CB03286-89) and in the stem of five accessions (i.e., Japan No.1, China collection No.1, China collection No.12, CB03286-89 and 99797). Accessions had a great influence on the content of phenolic compounds. So, accessions-specific phenolic compound profiles might be helpful for commercial use or production of phenolic compounds in L. chinesis.