• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.243-249
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• 2011

This study investigated the physiological and antioxidant activities of green, oolong, and black tea extracts. The crude catechin extract yields of green, oolong, and black tea were 4.9%, 3.4%, and 2.5%, respectively. Total phenol contents of green, oolong, and black tea were 40.9%, 43.0%, and 38.5%, respectively. The order of the electron donating abilities of green, oolong and black tea were green tea>oolong tea>black tea extracts. The SOD-like activities of green, oolong and black tea extracts at 5,000 ppm were 21.2%, 17.5% and 13.9%, respectively. The nitrite-scavenging abilities of green, oolong and black tea extracts were higher than that of ascorbic acid (p<0.05). Antioxidant activities in soybean oil substrates at 500 ppm were in the order of green tea>oolong tea>black tea${\geq}$BHT (200 ppm). Therefore these results showed that the physiological and antioxidant activities of green tea were better than those of oolong and black tea.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.377-381
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• 2002

The antioxidative effect of tea extracts from green tea, oolong tea and black tea was investigated. The extraction yields of crude catechin were green tea 5.4%, oolong tea 3.5%, and black tea 2.5%. Green tea, oolong tea and black tea of crude catechin showed antioxident activity at concentrations of 200ppm, and the oolong tea showed highest antioxidant effect. The browning intensities(at 420 nm) of green, oolong and black tea were 0.140, 0.582 and 0.915, respectively and green tea showed highest hydrogen donating ability(HDA) and than followed by oolong or black tea. Also, when the crude catechin(100 ppm) was used in combination with ${\alpha}$-tocopherol(50 ppm) and ascorbyl palmitate(50 ppm), the crude cathechin showed very strong synergistic effect, comparable to that of crude catechin(200 ppm).

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.759-763
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• 1993

The antioxidant effects of aqueous green tea extract(AGTE) obtained from green tea and its combinations with several synergists on lard were investigated to equalize with that of crude catechin in green tea. The antioxidant effect of crude catechin was about 3-fold higher than that of AGTE. The suitable synergists for AGTE were ${\delta}-tocopherol$ and lecithin, while the tendency of their synergistic effects was different from each other. Addition of ${\delta}-tocopherol$ within 0.05% dosage to lard showed significant synergistic effect, and its synergistic effect decreased with the concentration of AGTE over 0.1% dosage. In combination of AGTE and lecithin, they gradually enhanced synergistic effect on lard with increasing the concentration. The combinations of AGTE, ${\delta}-tocopherol$ and lecithin showed intense synergistic effects and the optimum level of the each component was 0.1% AGTE, 0.05% ${\delta}-tocopherol$ and 1% lecithin. By adding the optimum level of three components to lard, the induction period was lenghtened approximately 8-fold than that of the control owing to their synergism. Comparing the antioxidant effect between the AGTE with synergists and crude catechin, the former was 60% and 20% higher than the latter at 0.1% and 1% dosage respectively.

• Journal of Life Science
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• v.6 no.2
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• pp.104-110
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• 1996

The present study was conducted to elucidate the functional property of tea extract obtained from tea extracts, semi-fermented tea(oolong tea) and fermented tea(black tea). Tea extracts exhibited remarkable nitrite-scavenging actions, and the action increased with the increased of the amount of tea extracts. The nitrite-scavenging actionof tea extracts showed pH dependent, highest at pH 1.2 and lowest at pH6.0. The nitrite-scavenging rate in tea extracts/amine/nitrite systems proved to be faster than that in amine/nitrite systems. To screen the nitrite-scavenging factors, tea extracts were fractionated into water-soluble, methanol-soluble, methanol-precipitate and crude catechin fraction. Among these fractions of tea extracts, the crude catechin fraction possessed greater nitrite-scavenging action than the other fractions. The nitrite-scavenging action of tea extracts increased with the contents of total phenols and an absorbance at 280nm, nitrite-scavenging factors were supposed to be and catechins in tea polyphenol compounds.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.720-727
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• 2017

Antioxidants are known to affect the feeding habits of termites and a good source is pine bark which contains high levels of antioxidants which can be extracted with neutral solvents. In this study procyanidins (PCs)-rich MeOH-extract and a hot-water extract (HWE) were prepared from Pinus radiata bark. HWE was further separated into crude PCs (CPCs), polymeric PCs (PPCs), and low-molecular-weight PCs (LMWPCs) fractions. The MeOH extract and these fractions were examined for termite (Reticulitermes flavipes Kollar) antifeedant activities using a no-choice test. Catechin was used as a positive control. The LMWPCs was found to be the most effective deterrent to termite feeding. The comparative efficiency of the compounds tested were LMWPCs > PPCs > CPCs > MeOH extract, with the latter being more dependent on molecular weight than on its antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.501-505
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• 2003

In order to use as a new functional food material, chemical components of propolis and its extracts were surveyed. The contents of crude fat, nitrogen free extract, crude protein, ash and crude fiber in propolis were 86.41%, 7.32%, 2.71%, 1.05% and 0.20%, respectively. The mineral contents were in the order of Na (120.40 mg%), Ca (115.40 mg%), K (105.87 mg%) and Ca were higher in water extract than alcohol extract. Free sugars were composed of sucrose 152 mg%, glucose 114 mg% and fructose 6 mg%. The major amino acids of propolis were lysine 395.29 mg%, cystine 267.66 mg% and glutamic acid 248.14 mg%, respectively. Eight fatty acids in propolis were identified and the major fatty acids were oleic acid (51.89%), myristic acid (20.86%) and palmitic acid (20.28%). Myricetin, quercetin, apigenin and kaempferol were shown as major flavonols and total flavonol contents were higher in 50% ethanol extract than any other extracts. Major Polyphenol compounds in four kinds of extracts were gallic acid, chlorogenic acid, catechin, epigallocatechin gallate, epicatechin and epicatechin gallate.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.273-276
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• 2000

In the course of surveying the anti-plaque agents for dental caries prevention, the extract of Korean green tea leaves (KGTL) was tested for inhibitory activity against Streptococcus mutans adhering to glass surfaces in the presence of crude glucosyltransferase (GTase). The extracts of KGTL showed a positive inhibitory activity against GTase. The active compound was purified through Sephadex LH-20 and MCI gel CHP-20P columns. A positive reaction was shown in the anisaldehyde-$H_2SO_4$ test, which confirmed the condensed tannin. The inhibitory compound was identified as 3-galloylprocyanidin $B_3$ through IR, negative FAB-mass, and $^{1}H$-NMR spectroscopic analyses. Acetone extract and 3- galloylprocyanidin $B_3$ of KGTL showed inhibitory effect against GTase. The percent of inhibition was determinated to be 71.84% (P<0.01) with 10 mM 3-galloylprocyanidin B3. The 3-galloylprocyanidin $B_3$, which possessed a galloyl, showed a higher inhibitory activity against glucosyltransferase than monomeric (+)-catechin and procyanidine $B_3$ which had no galloyl group.

• Food Science and Preservation
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• v.12 no.2
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• pp.156-160
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• 2005

To obtain basic data utilizing chestnuts as a raw food material, proximate analysis was conducted. Chemical component of chestnut flesh were $63.60\%$ moisture, $118\%$ ash, $3.02\%$ crude protein, $0.615\%$ crude fat, $1.21\%$ crude fiber, and $30.37\%$ nitrogen free extract, respectively. The weight ratio of tegmen, seed coat and flesh of chestnut sample were 17.05, 14.9, and $68.05\%$, respectively. The total amino acid contents of flesh and seed coat were $2,994\;mg\%$ and $1,450\;mg\%$, respectively. The total amount of free amino acids was less than that of total amino acids. As results of mineral analysis, the content of K was higher than that of any other minerals. The contents of maltose and sucrose were higher than those of fructose and glucose. The total polyphenol contents of tegmen, seed coat, fresh, leaf and bark were $9.56\;mg\%$, $0.047\;mg\%$, $0.23\;mg\%$, $15.44\;mg\%$ and $17.85\;mg\%$, respectively.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.119-125
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• 2002

Phytoestrogens are non-steroidal compounds fecund In a variety of plants, which exert estrogenic effects in animals. In this study, the physico-chemical properties of Iranian black pomegranate extract and its products as preliminarily research for the developing of natural estrogen supplement were evaluated. The chemical components of Iranian black pomegranate extracts and its product (Forever 120) were analyzed. Proximate compositions of pomegranate extracts were as follows; crude lipid 0.4%, crude protein 0.9%, crude ash 1.4% and carbohydrate 42.0%. Major amino acids of pomegranate extracts are glutamic acid (1310.0ppm), aspartic acid (896.2ppm), arginine (877.7ppm) and phenylalanine (57.5ppm). Fatty acid compositions of pomegranate extract 1ibid extracted by chloroform-methanol (2:1) were myristic (13.1%), stearic (69.4), oleic acid (6.8%) and palmitic acid (8.3%). Mineral elements were ferrous (6640.0ppm) and potassium (2550.8ppm). Vitamins were composed of ascorbic acid(20.0mg/100g), Vit. B$_1$(0.12mg/100g) and niacin (0.80mg/100g). 20 phytoestrogens and 20 estrogens of pomegranate extracts were detected Daidzein (0.29ppm), quercetin (9.75ppm) genistein (0.29ppm) and 17 $\beta$ -estradiol(0.15ppm). Above the chemical components of pomegranate extracts were compared with that of pomegranate its product or other isoflavon concentrates.

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.171-177
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• 2008

Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of $25\;{\mu}g/ml$ whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at $10\;{\mu}g/ml$ level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at $50\;{\mu}g/ml$ level of EGCG. Only four strains were inhibited at $100\;{\mu}g/ml$. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG ($500\;{\mu}g/ml$ and $1,000\;{\mu}g/ml$) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.