• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.270-270
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• 2017

Brown rice flour (BRF) was treated with different carbohydrases (Viscozyme, Termamyl, Celluclast, AMG, Ultraflo, and Pentopan), and then aqueous alcoholic extracts (70% ethanol) from the treated RBF were examined for their phenolic compositions and antioxidant activities (ABTS and DPPH radical scavenging activity). All the carbohydrases tested induced significant increases in ABTS radical scavenging activity (2.1-3.0 times). Moreover, These enzymes increased the amount of extractable free phenolic acids by 10-15 times, especially for ferulic and p-coumaric acid. Among the enzymes tested, Pentopan which was active in arabinoxylan hydrolysis appeared to be most effective in increasing the free phenolic acid content and ABTS radical scavenging activity than other enzymes. Enzymatic hydrolysis of cell wall polysaccharides in BRF could be used as an effective procedure for raising the amount of extractable phenolic acids and thus increasing the antioxidant activity of BRF extract.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.141-146
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• 2014

In this study, we investigated on antioxidative activities and tyrosinase inhibitory activities of methanol extract and its fractions from roots of Arctium lappa. The total phenolic compound and flavonoid content of the ethylacetate fraction was found to be 818.29 mg/g and 360.59 mg/g as the highest content. In the measurement of DPPH radical scavenging ability and tyrosinase inhibitory activity, the ethylacetate fraction was higher than the other fractions and the extract. In addition, comparative analysis of phenolic compounds by liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring (MRM) with negative-ion electrospray ionization mode. The main phenolic compounds in the extract and fractions of roots from Arctium lappa were cynarin and chlorogenic acid. The main phenolic compound of the ethylacetate fraction was cynarin. n-Butanol fraction had a significantly higher chlorogenic acid content than other samples. In conclusion, DPPH radical scavenging ability and tyrosinase inhibitory activity of the cynarin-riched ethylacetate fraction showed the highest activity.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.35-40
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• 2010

This study was carried out to enhance the analytical methods of phenolic compounds in mainstream cigarette smoke using high efficiency column and RRLC(Rapid Resolution Liquid Chromatography) system, and to compare these methods. RRLC system offers significantly faster results with higher data quality of phenolic compounds than conventional HPLC, but it is disadvantage that it is expensive. On the other hand, the method using monolithic column offers faster results by the use of conventional HPLC system without new equipment introduction. In this study, we used the linear type smoking machine and Health Canada method for pre-treatment process of phenolic compounds. The analysis time of phenolic compounds using RRLC and monolithic column was individually 8 and 15 minutes, whereas in the conventional HPLC it was 45 minutes. These new methods were accompanied with the minimal solvent consumption and had lower analysis costs. Also, we proved that there were no difference between new methods and conventional method in accuracy by statistic.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.107-111
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• 2001

Physical and chemical characteristics of four white-and one yellow-fleshed peach cultivars were compared at optimum maturity stage. In addition, differences of phenolic composition, polyphenol oxidase (PPO) activities and PPO isozyme patterns in two peach types were also investigated. There are no significant differences in firmness and color values between two peach types, except for "Yumyung", a white-fleshed peach with the highest firmness, and "Hwangdo", a yellow-fleshed peach with the highest yellowness (b)* value. In general, the soluble solid/titratable acidity ratios, ascorbic acid and total phenolic contents were significantly higher for white-fleshed peaches than those for yellow-fleshed peach (p<0.05). Three major phenolic compounds, catechin, neochlorogenic acid and chlorogenic acid, were found in both the white-and yellow-fleshed peaches. Among them, catechin was the predominant phenolic compound in the white-fleshed peaches, followed by neochlorogenic acid, and chlorogenic acid. Meanwhile, neochlorogenic acid was present in the highest level of the yellow-fleshed peach, but levels of two other phenolic compounds were lower. PPO activities of the white-fleshed peaches were generally higher than that of the yellow-fleshed peach, with the one major band and two minor bands, and there were no big differences in PPO isozyme patterns between two different peach cultivars.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.397-401
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• 2008

Changes in the contents of total phenolic compounds in as Agrimonia pilosa well as their antioxidant capacity according to the havest time and positions were examined. The contents of the total phenolic compounds were determined by extraction with MeOH. Among havest times harvestry in July showed highest contents of the total phenolic compounds and harvestry in May showed lowest contents of the phenolic compounds. Among the 4 positions (root, branch, leaf, flower) of Agrimonia pilosa the root contained highest contents of the phenolic compounds. The antioxidant capacities of Agrimonia pilosa were increased roughly with increasing level of contents of phenolic compounds according to positions.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.341-348
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• 2018

This study was carried out to obtain the basic informations for phenolic compounds by various sections of Acanthopanacis Caulis. The phenolic compounds of Korean Acanthopanacis bark and lignum (Acanthopanax divaricatus var. albeofructus, Acanthopanax koreanum) were measured by the HPLC analysis. The content of total phenolic components of Acanthopanax koreanum bark (1.532%) was about 9.9 times higher than that of Acanthopanax koreanum lignum (0.155%). And also, The content of total phenolic components of Acanthopanax divaricatus var. albeofructus bark (0.420%) was about 2.8 times higher than that of Acanthopanax divaricatus var. albeofructus lignum (0.149%). Eleutheroside E, a functional ingredient of Acanthopanacis Caulis, showed 3.6 times higher contents of Acanthopanax koreanum bark (0.144%) than Acanthopanax koreanum lignum (0.040%). In the case of Acanthopanax divaricatus var. albeofructus bark (0.129%), the content of the eleutheroside E was 1.7 times higher than that of the Acanthopanax divaricatus var. albeofructus lignum (0.074%).

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.527-535
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• 2021

Legumes have been important components of the human diet. They contain not only protein, starch, and dietary fiber, but also various phenolic compounds such as flavonoids and phenolic acids. The importance of phenolic compounds to human health is well known due to their antioxidant activities. In this study, three legumes (adzuki beans, common beans, and black soybeans) frequently cultivated in Korea were evaluated for their total phenolic content (TPC) and antioxidant activities using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline 6-sulfonate)), and FRAP (ferric reducing antioxidant potential) assays. In addition, correlations between agricultural traits and antioxidant activities of these three legumes were analyzed. Antioxidant activities assessed by DPPH, ABTS, and FRAP assays and TPC showed wide variations among legumes types and accessions. Among the three legumes, adzuki beans showed higher TPC and antioxidant activity than the other two legumes. In correlation analysis, seed size showed negative correlations with antioxidant activities and TPC. In principal component analysis and hierarchical clustering analysis, each of the three legumes was clearly separate. Results of this study can be used as basic information for developing functional materials for each legume. They can also help us understand the overall antioxidant activity of the three legumes.

• Food Science and Preservation
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• v.11 no.1
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• pp.79-87
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• 2004

To investigate antioxidative effects of phenolic compounds separated from persimmon leaves(PL)(Diospyros kaki Thunb.) on the ethanol-induced hepatotoxicity in rat, Sprague-Dawley rats weighing 100-150 g were divided into 5 groups; control group(CON), PL(70 mg/kg) administered group(PEl), ethanol(5 mL/kg, 25％) administered group(ETH), PL(70 mg/kg) and ethanol administered group (PE2), and PL(140 mg/kg) and ethanol administered group(PE3), respectively. The antioxidative activity of persimmon leaves decreased in order of ethylacetate>interphase materials>n-butanol>chloroform>n-hexane>water fraction. The growth rate and feed efficiency ratio decreased by ethanol were gradually increased to the adjacent level of CON by administering PL. The serum activities of ALT, alkaline phosphatase and lactic acid dehydrogenase elevated by ethanol were decreased significantly. It was also observed that the activities of SOD, catalase, and GSH-Px of rat liver increased by ethanol were markedly decreased in PL administered group as compared to ETH. The GSH content of liver was decreased by ethanol, but that was increased in PE1 and PE2 compared with ETH as a dose-dependant manner. These results suggested that phenolic compounds separated from persimmon leaves have a possible protective and relievable effect on the ethanol-induced hepatotoxicity in rats.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.149-154
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• 2010

Interfacial evaluation was investigated for single-carbon fiber/phenolic and carbon nanotube (CNT)-phenolic composites by micromechanical technique and electrical resistance measurement combined with wettability test. Compressive strength of pure phenol and CNT-phenolic composites were compared using Broutman specimen. The contact resistance of CNT-phenolic composites was obtained using a gradient specimen by two and four-point methods. Surface energies and wettability by dynamic contact angle measurement were measured using Wilhelmy plate technique. Since hydrophobic domains are formed as heterogeneous microstructure of CNT in the surface, the dynamic contact angle exhibited more than $90^{\circ}$. CNT-phenolic composites exhibited a higher apparent modulus than neat phenolic case due to better stress transferring effect. Work of adhesion, $W_a$ between single-carbon fiber and CNT-phenolic composites exhibited higher than neat phenolic resin due to the enhanced viscosity by CNT addition. It was consistent with micro-failure patterns in microdroplet test.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.930-936
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• 2004

Effects of rice cultivars and degree of milling (DM) on composition, pasting properties, total phenolic contents, and distribution of phenolic acids were investigated. Rice and bran fractions with 94.4, 92.0, and 90.4% milling yields from brown rice of four cultivars (Odae, Nampyung, Chucheong, and Ilmi) were used. Fat and ash contents of milled rices decreased with increasing DM, whereas protein contents were not affected. In rice bran, differences in fat and ash contents by cultivars were higher than those caused by DM. With increasing DM, gelatinization temperature of rice flour decreased, whereas peak viscosity and hold viscosity at $95^{\circ}C$ increased. While cold viscosity, final viscosity, and setback varied among cultivars, DM had little effect. Total polyphenolic contents in brown rice, milled rice, and rice bran were 93.9-88.8, 30.3-71.9, and 310.0-541.6 mg catechin eq/100g, respectively. Major phenolic compounds were identified as ferulic and p-coumaric acids. Total phenolic content of brown rice (65.9-27.9 mg%) decreased with increasing DM, whereas ratio of ferulic acid composition increased. Chucheong and Ilmi varieties showed biggest reduction of phenolic acid contents by milling. In rice bran, ferulic and p-coumaric acids were 157.8-240.2 and 31.8-90.4 mg%, respectively. Contents of sinapinic, benzoic, and m-hydroxybenzoic acids in rice bran were higher than those of brown and milled rices.