• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.344-349
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• 2009

Optimum dyeing conditions of green tea extracts were investigated toward nylon, cotton, rayon, and tencel fabrics. Affinity of green tea extracts was exhibited much higher onto nylon fabric than the other cellulosics. As for nylon, the adsorption was increased with the increase of dyeing temperature and optimum dyeing pH was around 4~6. Buildup property of green tea extract was good showing a linear relationship between concentration of the extracts and color strength of dyed fabrics within experimental range. Color fastnesses were good to excellent in general except to light.

• Textile Coloration and Finishing
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• v.11 no.3
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• pp.15-22
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• 1999

This study investigated the mordanting effect of natural mordants such as camellia ash, bean chaff ash and pyrolignite of iron(Iron(II) Acetate) on silk fabrics dyed with green tea extracts. Experimental variables include the conditions of extraction and dyeing, and types of natural mordants. Inorganic ion contents In natural mordants were analysed by Induced Coupled Plasma Atomic Emission Spectrometer. In the ash Al, Fe, Si and Mn were in % unit, Cr and Ni were detected in ppm unit, and in the aqueous extracts of the ash all the metal ions were in ppm unit. On the other hand, fairly high content of Al(2.13% ) in camellia ash extract and Fe(7.91% ) in the aqueous extracts of pyrolignite iron were detected. The absorbance intensity of green tea extracts in UV-Visible spectrum increased with the temperature and time of extraction. The maximum absorption wavelength of the extracts appeared at 272.5nm and 210.5nm. The US values of silk fabrics dyed with green tea extracts were increased with temperature and time of dyeing. Surface color of silk fabric dyed with green tea extracts was 9.1YR, but it was changed from 7.9YR to 7.5YR by camellia ash extract and 7.4YR to 6.4YR by bean chaff ash extract with increase in mordant concentration. Pre-mordanted and post-mordanted fabrics with pyrolignite of iron were changed from 1.4YR to 1.1R and 7.2P to 4.2P, respectively.

• Journal of Nutrition and Health
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• v.32 no.4
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• pp.337-352
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• 1999

The effects of dried leaf powders and ethanol extract of persimmon, green tea and pine needle on lipid metabolism, lipid peroxidation and antioxidative activity were investigated in rats. Forty-nine male Spargue-Dawley rats weighing 107.8$\pm$1.8g were blocked into seven groups according to body weight. Rats were raised for four weeks with diets containing either 5%(w/w) dried leaf powders of one of three different Korea traditional teas, persimmon(Diospyros kaki Thunb), green tea(Camellia Sinensis O.Ktzc)or pine needle(pinus Koreansis Sieb. Et Zucc), or ethanol from equal amounts of each dried tea powder. Food intake, weight gain, food efficiency ratio, and weights of liver, kidney and epididymal fat were significantly higher in the green-tea-powder group, and significantly lower in the pine-needle-powder and pine-needle-extract groups. Persimmon-leaf powder was found to decrease plasma total lipid, triglyceride and cholesterol concentration by increasing fecal total lipid triglyceride and cholesterol excretions. Liver cholesterol concentration was significantly lower in the green-tea and pine-needle-extract groups. Red-blood-cell superoxide dismutase(SOD) and glutathione peroxidase(GSH-px) activities were significantly increased in rats fed green-tea extract. Liver SOD activity was increased in rats fed pine-needle powder or extract, and liver GSH-px activity was increased in rats fed greentea powder. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentration were both decreased in rats fed dried leaf posers or extracts of persimmon or green tea. It is believed that high vitamin E levels in persimmon leaf, and high flavonoid, beta-carotene and vitamin C levels in green tea effectively inhibited lipid peroxidation. In conclusion, persimmon and green tea leaves were effective in lowering lipid levels and inhibiting lipid peroxidation in animal tissue, while pine needles were effective and lowering body weight gain. From these results, persimmon and green tea leaves can be recommended in the treatment and prevention of chronic discorders such as cardiovascular disease, cancer and aging. As ethanol extracts from these teas were also effecitive in lowering tissue lipid levels and inhibiting lipid peroxidation, we recommend the use of discarded tea grounds for this.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.285-290
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• 2005

This study was aimed to determine microbiological Quality by adding green tea extracts to cook-chill foods. For this study, Pyeonyuk were blended with green tea extracts to different concentrations of 0, 2 and 3% and prepared in a cook-chill system. Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and A wand determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during cold storage at 3$^{\circ}C$ for five days. Green tea extracts improved the microbiological Quality and showed antibacterial properties when they are added to Pyeonyuk prepared in a cook-chill production system. The use of green tea extracts can be further explored as a means of enhancing freshness and Quality in cook-chill foods.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.1
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• pp.44-52
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• 2013

This study investigated hepatic functional improvement and anti-fibrotic effects of water extracts of black tea. Male Sprague-Dawley rats were divided into four groups (normal, control, and two experimental subgroups: Ba, Bb) and observed for 3 weeks. Liver fibrosis in rats developed from carbon tetrachloride ($CCl_4$) administration, except for the normal group. Except for the normal and control group, the two experimental subgroups were fed water extracts of black tea. The food efficiency ratio significantly increased in the experimental group compared to the control group. The experimental group had a significantly lower liver weight compared to the control group. The ratio of liver weight to body weight was significantly lower in the experimental group than the control group. The levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, and low-density lipoprotein-cholesterol in serum significantly decreased in the experimental group compared to the control group. The values of hydroxyproline and malondialdehyde in liver were even lower in the experimental group than the control group. In observations on liver histology, weaker inflammation and fibrosis were observed in the experimental group compared to the control group. In conclusion, water extracts of black tea help hepatic cells keep their functions, restraining and protecting the liver from impairments caused by $CCl_4$ administration, and can be effective as anti-fibrotic agents.

• Textile Coloration and Finishing
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• v.19 no.6
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• pp.12-20
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• 2007

Four kinds of natural dying solutions (natural colorant extracts)were obtained by extraction from sappan wood, black tea, peony, and clove using water as extracting solvent at $90^{\circ}C$ for 90 min with liquor ratio (solid natural colorant material/solvent water, weight ratio) of 1/10. The dyeing, colour fastness and deodorizing properties of fabrics (cotton, silk, and wool fabrics) dyed with natural colorant extracts were compared. It was found that these properties were significantly dependent on the concentration of extracts, the structure of colorant, and the kind of fabrics. The K/S value of dyed cotton fabric increased in the order of peony < sappan wood < clove < black tea, however, the values of dyed silk and wool fabrics were in the order of peony < sappan wood < black tea < clove. Colour fastness (light, water, and perspiration fastness) was in the range of 3 - 5 grade except for sappan wood. The deodorizing performance of fabrics dyed with various natural colorants extracts was in the range of 56 - 99%. The deodorizing performance increased in the order of peony < black tea < sappan wood < clove. Especially, the deodorizing performance of all fabrics dyed with clove was found to be the highest at 98-99%.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1316-1320
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• 1999

Antioxidative effect of ethanolic extracts of various tea materials(Camellia sinensis, Cassia tora, Lyc ium chinense, Polygonatum odoratum, Schizandrae chinensis) on red pepper seed oil was investigated. Ethanolic extracts were added to red pepper seed oil at a concentration of 0.05%(w/v). Two experimental conditions were employed : 50$\pm$0.1oC for 45 days and 150$\pm$3oC for 24 hours. Oxidation of red pepper seed oil was determined by measuring peroxide value and acid value. Electron donating ability(EDA) and total phenolic contents of each extract were also determined. The result showed that the extracts possess an antioxidative activities. The effectiveness of them was in the following order: C. sinensis>C. tora>P. odoratum>S. chinensis >L. chinense. Ethanolic extracts of C. sinensis showed substantially higher EDA value and total phenol contents than other tea materials. These results indicate that the antioxidative effect was strongly related with EDA and total phenol contents.

• Food Science and Preservation
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• v.24 no.6
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• pp.871-878
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• 2017

The objective of this study was to compare antioxidant activities of green tea, rosemary, lemon and bamboo leaves extracts using three different extraction methods (80% ethanol sonication extraction, distilled water autoclave extraction, distilled water extraction at room temperature). As a result, green tea and rosemary extracts showed relatively high antioxidant activities compared with those of lemon and bamboo leaves. These green tea and rosemary extracts were subsequently added to soymilk and their mixtures were examined for antioxidant activities. Soymilk added with 10% green tea distilled water autoclave extracts and distilled water at room temperature extracts showed relatively high DPPH, $85.09{\pm}2.26%$, $84.38{\pm}1.97%$, and ABTS radical scavenging activities, $73.43{\pm}2.78%$, $81.34{\pm}4.78%$, respectively. On the other hand, soymilk added with 10% rosemary distilled water autoclave extracts showed remarkably higher DPPH radical scavenging activity while their ABTS radical scavenging ability was similar to that of non-added soymilk. In conclusion, our results suggest that the addition of green tea distilled water autoclave extracts, distilled water at room temperature extracts and rosemary distilled water autoclave extracts to soymilk could contribute to the development of added value soymilk products with increased antioxidant activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.100-106
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• 1999

Use of chemical preservative for controlling harmful microorganisms in food products has been debated due to public concerns about food quality because of perceived toxic and carcinogenic potential. Thus, use of non toxic natural antimicrobial agents has become essential. This study was investigated to determine the antimicrobial activity of water or ethanol extract of commercially available tea, and of solvent fractionated ethanol extracts obtained from steamed green tea. Both of water and ethanol extracts of green tea(steamed or roasted), oolong tea and black tea exhibited strong antimicrobial activity against gram positive and negative bacteria, but not effective against yeast and mold. Also, antimicrobial activity of ethanol extract of 4 different kinds of tea was stronger than that of water extract. Among 4 different tea, ethanol extract of steamed green tea was further fractionated. One thousand g/disk buthanol extract had the strongest antimicrobial activity against bacteria and mold. The concentration of the antimicrobial activity of buthanol extract in tested microorganisms ranged from 125~1000 g/disk except for Rhizopus javanicus. Antimicrobial activity of buthanol extract of steamed green tea was not destroyed by heating at 100oC for 60 min and at 121oC for 15 min, which is very stable over heat treatment. The inhibitory effect of the buthanol extract on the growth of Listeria monocytogenes and Staphylococcus aureus was investigated. Growth of both strains was started in the presence of 250 and 500 g/ml after 12 and 24 hour respectively, whereas complete inactivation of both strains was occurred in the presence of 1000 g/ml.