• Korean Journal of Medicinal Crop Science
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• v.10 no.5
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• pp.379-383
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• 2002

The significant chemical components estimating the quality and growth characteristics in different parts of tea plants were compared and analyzed in the shoots of shading tea plants. The results are summarized as follows. The leaves length, leaves width and weigth of 100 buds in the leaves were increased with growing, while the leaf moisture was decreased. The contents of total nitrogen, caffeine, vitamin C and saponin in the leaves were decreased with growing, while those of total amino acid and chlorophyll were the highest in the 4th leaves and in 3rd leaves, respectively. The content of tannin ranged from 9.53% to 11.23%. The content of tannin at the 1st leaves was the highest as 11.24%, but that of the 4th leaves was the lowest as 9.53%. the content of fatty acid at the 2nd leaves was the highest as 3,594mg/100g, and that of the 5th leaves was the lowest as 2,782mg/100g. The contents of palmitic acid and stearic acid were the highest in the 5th leaves, but those of oleic acid, linoleic acid and linolenic acid were the highest at the 2nd leaves. In conclusion, the 5th leaves among tea shoots plucked after shading for 15 days could be used to manufacture powder green tea.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.308-314
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• 2009

In this study, we examined the composition of catechins, theaflavins and alkaloids in leaves during processing to fermented black tea, which is produced by withering, roll breaking, and fermentation of Korean Yabukida tea plant. In addition, we determined the optimal conditions for the production of fermented black tea. The average moisture content in fresh leaves was 70.85%, which dropped to 3.07% in fermented black tea at the last stage of production. When the leaves were analyzed by HPLC, seven types of catechins, four types of theaflavins and three types of alkaloids were identified. The levels of catechins, theaflavins, and alkaloids were then evaluated after being processed into fermented tea. From these experiments, we found that the level of theaflavins, which determines the property of the tea, increased during fermentation. This effect resulted from the change in EGCG, ECG, EGC, EC during the process of fermentation. We also found that the maximal amount of theaflavins was created after 1-2 hours of fermentation. Thus, our results imply that the best condition for producing fermented black tea would be to ferment for 1-2 hours.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.601-610
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• 1993

With the purpose of labour reduction in tea plucking operation with portable type machine, the influence of frame angles and tea leaves weight on the grasping forces of each finger were investigated. At the measurement of the grasping force of each finger except for thumb, grip strength dynamometers were attached at the grasping position of the frame instead of handle grips. A series of measurement was carried out changing frame angles of the tea plucking machine and the weight of tea leaves. With the obtained results of the experiments , the influences of the frame angles and the weight of the tea leaves on the grasping forces of each finger were analyzed. Some reasonable suggestions for the labour reduction in the tea plucking operation with portable type machine were obtained in the aspect of normalizing the balance of the grasping force on each finger and these suggestions are expected to contribute the labour reduction of the tea plucking operation.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.1-6
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• 1992

Chemical composition was determined to evaluate the quality of Panel ginseng-leaf tea over green teas. Ginseng-leaf tea was shown to contain higher contents of soluble matter, ascorbic acid and lower contents of tannins, as compared to tea leaves. The profiles of ginsenoside and sugar of ginseng-leaf tea were noticeably different from those of ginseng roots and the sample maintained high levels of these components under the manufacturing process. Total unsaturated fatty acids and free amino acids were estimated to be decreased in ginseng-leaf tea as compared to those of ginseng leaves. The compositions of amino acids and minerals in ginseng-leaf tea were similar to those of tea leaves and glutamic acid, aspartic acid, leucine, calcium, potassium, sodium, and copper were found to be major components.

• Culinary science and hospitality research
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• v.16 no.4
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• pp.220-229
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• 2010

Brewing tea with regular teapots can cause a problem in keeping the temperature of the tea. Cold weather, a cold teapot, and/or the temperature of tea leaves make tea cold, lowering the temperature of the tea leaves that can also make the flavor of the tea leaves worse. This experiment shows both the problem and the solution to the temperature problem of tea leaves. To maintain the appropriate temperature and reduce the problem, we researched and developed a special straw for tea leaves as a result of this experiment The straw consists of various filtering holes(diameter 1~2 mm) with the height of 5 mm from the very bottom of the straw. Using the straw is better to keep higher temperature, better flavor, and the smell of tea. Also, the sensory evaluation shows that the overall taste of tea is improved(p<0.05).

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.1-7
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• 2010

The antioxidant activities and flavonoid contents of the mulberry leaves and the ginko leaves teas were investigated. The antioxidant activities were examined by FRAP and DPPH radical scavenging assays, and total phenolic content and the flavonoid contents by HPLC were also determined. The ginko leaves tea showed the highest antioxidant activities and antioxidant contents, while the wild mulberry leaves tea showed the lowest. The antioxidant activities of the mixture tea of wild mulberry leaves and ginko leaves were increased more than the wild mulberry leaves tea. The flavonoid contents of the leaves(ginko, wild mulberry and mixture) powders were higher than those of infusion teas. Compared with wild mulberry tea, the mixture tea showed a little increase of flavonoid contents. The total phenolic contents and the flavonoid contents of the teas showed good correlations with their antioxidant activities, such as FRAP and DPPH radical scavenging activities(${\geq}0.8727$). The antioxidant capacities of wild mulberry leaves tea could be enhanced by the addition of the ginko leaves.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.383-385
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• 1995

Occurrence of white scab of tea (CAmellia sinensis) showing numerous, small, circular, reddish or yellowish brown spots on young tea leaves was observed at a tea plantation of Boseung, Chonnam, from May to June in 1992-1994. At the late growth stages, the center of the spot became light gray. The causal fungus of the white scab was identified as Sphaceloma theae Kurosawa. Symptoms were produced 5∼6 days after inoculation by the artificial inoculation of s. theae conidia, which was similar to those on naturally infected leaves.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.63-71
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• 2005

Panax ginseng leaves are produced as the by-product when Panax ginseng roots were harvested. The Panax ginseng leaves was examed for the applicable possibility as the functional food. In this study, the changes in chemical composition of Panax ginseng leaves was examed by three methods as the hot-air dried(DRT), the aged tea(AGT) and the heat processed tea(HPT). The general composition of Panax ginseng leaves tea was shown as similar results in 3 different process methods. The level of the crude lipid and reducing sugar concentration were decreased slightly in HPT. The free sugar content of DRT was higher than the HPT and AGT. The existence of the higher content of free sugar composition in order are sucrose, fructose and glucose. The concentration of serine was the highest in the free amino acids, which were shown from 309.6 mg% to 336.6 mg%. The contents of free amino acid in Panax ginseng leaves made by DRT was higher than by AGT and HPT. The concentration of Ca was shown as the highest content among the minerals and was 2,115 mg%. The contents of minerals were existed in order of Ca, K, Mg, P, Na, Mn, Fe, Zn and Cu. But there were hardly any remarkable differences of mineral concentrations of Panax ginseng leaves tea made by different processing methods. The concentration of water soluble solid of Panax ginseng leaves tea processed by HPT was higher than by DRT and AGT. The concentration of ascorbic acid was shown the highest value of 424.4mg% in HPT. There was no differences in the fatty acid composition according to their processing methods. The concentration of palmitic acid was higher than that of other fatty acid. The order of fatty acid concentration were palmitic aicd, linoleic acid, linolenic acid, oleic acid and stearic acid, abundantly. As a conclusion, HPT was shown as the best process method for the production of Panax ginseng leaves tea.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.128-134
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• 2017

This work presents the adsorption capability of green tea and ginseng leaves to adsorb heavy metals such as Cd(II), Cu(II), and Pb(II) in aqueous solution. FT-IR analysis indicates the presence of oxygen containing functional groups (carboxyl groups) in two kinds of leaves. High pH condition was favorable to the adsorption of heavy metal ions due to the enhanced electrostatic attraction and the precipitation reaction of metal ions. The adsorption of Cd(II), Cu(II), and Pb(II) reached equilibrium within 10 min, achieving high removal efficiencies of 80.3-97.5%. The adsorption kinetics data of heavy metal ions were fitted well with the pseudo-second-order kinetic model. The maximum adsorption amounts of Cd(II), Cu(II), and Pb(II) ions were 8, 3.5, and 15 mg/g, respectively, in the initial concentration range from 0.15 to 0.75 mM. Based on the fitting data obtained from isotherm models, heavy metal adsorption by green tea and ginseng leaves could occur via multi-layer sorption.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.49-58
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• 2008

This research was carried out to use green tea leaves powder for scavenging effects of volatile organic compounds on the UV varnishes and adhesives of fancy cherry veneer overlaid on the PF resin bonded Meranti plywood. The results are as follows: 1) Green tea leaves contained 9.85% of polyphenol compounds. 2) FT-IR results showed green tea leaves had effects to react with benzaldehyde and ethyl hexyl alcohol to form a chemical bond. 3) 2.5% of green tea leaves powder content was proper for scavenging effect on the UV varnishes and adhesives of fancy veneer overlaid on the PF resin bonded plywood 4) 20 liters small chamber test indicated excellent emission speed results such as $0.089mg/m^2hr$ of TVOC and $0.001mg/m^2hr$ of HCHO (on 7th day), as compared with standard (less than $0.1mg/m^2hr$ of TVOC and $0.015mg/m^2hr$ of HCHO emission are the excellent grade).