• Korean Journal of Medicinal Crop Science
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• v.17 no.1
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• pp.21-25
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• 2009

The results on the useful functional compounds of kenaf (Hibiscus cannabinus L.) leaves cultivated in reclaimed lands and the biological activity effects of extracts were as follows. On 98 days after sowing (DAS) Tainung-2 showed the highest total chlorophyll content (1.68 mg/g), and on 141 DAS Dowling showed higher chlorophyll content (1.50 mg/g) than the other two did. In all cultivars the total chlorophyll content was higher on 141 DAS than on 98 DAS. Total polyphenol and total flavonoid contents were the highest in Tainung-2 (30.50 mg/g and 57.03 mg/g, respectively), and total polyphenol and total flavonoid contents (30.50 mg/g and 57.03 mg/g, respectively) were the highest in 30% ethanol extraction. Ascorbic acid contents were higher on 141 DAS than on 98 DAS in three cultivars. SOD activities of kenaf leaf extract were generally over 90%. DPPH radical scavenging activity of Tainung-2 was higher than others.

• Analytical Science and Technology
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• v.11 no.6
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• pp.478-484
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• 1998

Distribution of polyphenolic compounds in oak tree (Quercus acutissima, three years old) collected from Forest Research Institute located in Kwang Leung, Kyeonggi-do, Korea, was investigated using chromatographic studies. Total 25 polyphenolic fractions were separated from an oak tree, of which 15, 11, 7, 7, and 4 were in leaf, stem, root, bark, and seed, respectively. Catechins are predominant compounds in the polyphenols and some flavonoids were also identified. Distribution of polyphenols was relatively different in each part. Polyphenols in all of the part studied, except leaf where polymer was not detected, were existed as polymeric, oligomeric, and monomeric forms. Relative contents of total polyphenols in Quercus acutissima were the highest in bark, followed by root, leaf, acorn, and stem. Monomeric polyphenols were the predominant compounds present in all of the part of the oak tree.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.195-200
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• 2009

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.200-208
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• 2004

This study was performed to investigate the change of biologically functional compounds and antioxidant activities in Hizikia fusiformis with drying methods. As biologically functional compounds, the contents of minerals(K, Ca, Ma, Mg, Fe, Cu, Mn and Zn), vitamins(vitamin C, ${\beta}-carotene\;and\;{\alpha}-tocopherol$) and total polyphenol were analyzed. And antioxidant activity was determined through free radicals(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and linoleic acid peroxidation inhibitory activity. The contents of minerals were not affected by drying methods however vitamins and total polyphenol were lost more by sun-drying than other drying methods studies. Total polyphenol was preserved by freezing-drying than other drying methods studies, resulting in high antioxidant activities.

• Food Science and Preservation
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• v.9 no.3
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• pp.332-337
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• 2002

This study was undertaken in order to compare reflux extraction(RE) and microwave-assisted extraction(MAE) in extraction efficiency and establish optimum microwave extraction conditions in obtaining Ligularia fischeri extracts. A considerable reduction in extraction time was accomplished by MAE. When 70% methanol 50% methanol 70% ethanol, or 50% ethanol was used, MAE extract contained equal levels of soluble solid and total polyphenol as obtained by RE. The optimum microwave-assisted extraction conditions for Ligularia fischeri were achieved by 120∼150 watts of microwave energy and 4∼8 minutes of extraction time. No significant changes were found in antioxidant activity with DPPH scavenging method over the variation of microwave energy or extraction time. The use of diluted methanol or ethanol improved soluble solid content(30%), total polyphenol content(2.7%) and antioxidant activity(68%).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.409-413
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• 2012

The physiological activities and amino acid compositions of dried lavers of Porphyra from the Jangheung, Seochen and Haenam coasts were determined. The ethanol extract of the Haenam dried laver exhibited the greatest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (56.1%), ferric-reducing antioxidant potential (FRAP) value(86.5 mM) and total polyphenol content (3.51 ppm) of these dried laver products. In addition, there was a strong positive correlation between the antioxidative activity and total polyphenol content of the laver products, suggesting that polyphenol compounds contribute to the antioxidant capacity in the ethanol extract of dried laver. However, there was no difference among the extracts in terms of cell proliferation activity. Fourteen combined amino acids were identified in oligopeptides from the dried laver products. Of the three extracts, that of the Haenam dried laver contained the highest levels of both free and total amino acids including alanine, glutamic acid, taurine, phosphoserine, and aspartic acid.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1265-1274
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• 2012

This study was conducted to investigate the extraction characteristics including total polyphenol compound content (TPC) and the antioxidative effect of Rumex crispus root extract on commercial corn oil. Extraction yield was increased with extraction temperature but decreased with extraction ratio. No significant differences in aromatics content were found among the extracts prepared with various extraction conditions; extraction ratio, extraction temperature, extraction pH and composition of extractant. Total flavonoid content of the extract was increased with extraction temperature and extraction pH, and highest value of it was found when extractant composition of ethanol in water was 75%. Total polyphenol compound content (TPC) of the extract with 10 fold extraction ratio showed the highest value, but no significant difference in TPC was found with extraction temperature. Reducing power and DPPH (${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging ability (RSA) of the extract in spectrophotometric absorbance were decreased with extraction ratio but increased with extraction temperature and showed 63.1%~98.4% and 67.6%~86.7% of those of ascorbic acid in reducing power and DPPH RSA, respectively. The antioxidative effects of the extract on corn oil were 84.8~93.0% of that of commercial butylated hydroxytoluene, the antioxidant index value was highest when the ethanol composition to water in extractant was equal ratio.

• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.263-270
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• 2016

Background: In this study, microwave extraction was used, which is an effective method to extract useful bioactive substances as it requires low quantities of solvent and short time periods. The aim of this study was to determine the optimal extraction conditions for Agrimonia pilosa Ledeb. Methods and Results: The independent variables were ethanol concentration, microwave power, and extraction time, each of which had five levels. The dependent variables were total polyphenol and total flavonoid content, and DPPH radical scavenging activity. To determine the optimal extraction conditions for bioactive compounds, a response surface methodology was employed. Contour maps were generated from polynomial equations. The optimal conditions were then assumed by superimposing these contour maps. Based on the resulting graph, the optimal microwave extraction conditions for Agrimonia pilosa Ledeb were determined as 42 - 48% ethanol concentration, 240 - 280W microwave power, and 13 - 20 min of extraction time. Conclusions: Ethanol concentration had a significant effect on microwave extraction, in terms of total polyphenol and total flavonoid content, as well as DPPH radical scavenging activity. Microwave power and extraction time influenced the total polyphenol content, but not the total flavonoid content or the DPPH radical scavenging activity.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.44-47
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• 1971

(1) Suppression of the seed browning was observed when 3% $CO_2$ conditions were given to a small-type sweet pepper Zairaisisi stored at various CA conditions of a low temperature. (2) When changes in the total polyphenol content for low temperature storage were determined, the highest peak of polyphenol level appeared later than the control which conceded well with the change of seed out-looks. (3) The seed browning effect of enzyme solution for polyphenol extracts of pepper seeds stored at a low temperature with various CA conditions showed a parallelism to the change in polyphenol oxidase activity. (4) There was no striking influence of various CA conditions on maintaining consistent peroxidase activity of pepper seeds.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.413-417
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• 1984

To examine enzymatic browning of apple wine, changes of active bands of polyphenol oxidase (EC 1.10.3.1) as well as polyphenol substances related to browning of apple wine were investigated during wine brewing. The decrease of total phenol was remarkably inhibited by the addition of sodium metabisulfite. In the meantime, auto-oxidation of catechol in a model system increased proportionally as the reaction pH and temperature increased. Catechol oxidation, however, was not detected at $4^{\circ}C$ below pH 5.0. Polyacrylamidegel electrophoretic patterns showed that the apple (Jonathan) indicated 4 bands with polyphenol oxidase activity, designated a, b, c and d whose Rm were 0.21, 0.30, 0.41 and 0.51, respectively. Among these, 2 bands, a and c remained until 5th day fermentation and only c band after 6th day fermentation. After pasteurization of apple wine at $60^{\circ}C$ for 30min, c band also remained.