• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.177-179
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• 1992

The theanine contents of commercial green teas manufactured by the different harves times(1st tea, 2nd tea and 3rd tea) and processes(steamed and parched teas) were determined by amino acid analyzer. There were remarkable differences in the theanine contents among teas of the different harvest times. The theanine content in 1st steamed green tea was 2235 mg% and one in 1st parched green tea was 2106 mg%. The theanine contents in 2nd, 3rd tea were gradually decreased. There were slight differences in the theanine contents among teas of the different process.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.817-826
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• 2009

As UV radiation to the earth increased over recent years, many adverse effects of UV radiation have been reported. There are needs to develop UV-protective apparel and accessaries to protect skin from these harmful effects. Cellulose is one of the most frequently worn fiber during summer time. However, celllulose shows very low UV-protective property especially in case of thin and low fabric content. In this study, UV-protective cellulose textiles were developed using chiotsan mordanting and green tea dyeing. The repetition effect of chitosan and green tea treatment were focused. Three different cellulose fibers, cotton, linen, and ramie, were used for this study. All chitosan mordanted and green tea dyed fabrics showed increases in UV-protective property. The color of fabrics tended to darker as the numbers of mordanting process and green tea dyeing increased. UV-protective property did not increase significantly upon the repetition of mordanting and green tea dyeing treatment except ramie fabric. UV protective property was persisted upon washfastness test in all three cellulose fiber types.

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.609-614
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• 2007

Quality characteristics of dasik were studied with varied the levels of rice grain particle size and green tea powder and compared them with commercially sold dasik. Among the samples with the same number of grinding times, the sample groups with the higher amount of green tea showed significantly the less mosture content(p<0.05). Hardness was higher in the samples containing higher amount of green tea among the ones with the same grain size (p<0.05). The M13G0.5 was evaluated to have the highest savory aroma with significance (p<0.05), and C1 to have the highest sweetness by sensory analysis. The developed dasik samples with lower rice grain particle size had significantly lower adhesiveness, chewiness, gumminess, and cohesiveness compared to those of commercial sample groups. In sensory tests, the compared groups showed significantly the higher savory aroma and flavor and very lower hardness when compared to those of commercial sample groups. With the results above, dasik with with varied the levels of rice grain particle size and green tea powder were developed with improved qualities compared to those of commercially sold dasik.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1011-1020
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• 2003

The present study was conducted to examine sensory characteristics of non-fermented tea and fermented teas with fermented times of 0 hr (green tea), 10 hrs (mild fermented tea), 17 hrs (medium fermented tea), 24 hrs (black tea), respectively. The lightness of tea powder and tea extract got lower, and the redness and the yellowness of those got higher as tea was more fermented. The result of sensory evaluation about the extracts of non fermented tea and fermented teas showed that the preference of flavor got higher in the more fermented tea but one got lower in a mild fermented tea according to temperatures, respectively. The preference of taste got higher at 60∼7$0^{\circ}C$ extracts in the green tea and got the highest at 80∼9$0^{\circ}C$ extracts in the medium fermented tea and black tea. A total of 76 flavor components was detected in non fermented tea and the total contents of those were 129.9 mg/kg. The major components were linalool, geraniol, nerolidol, benzyl alcohol, and linalool oxide. A total of 76 flavor components was detected in the mild fermented tea and total contents of those were 159.1 mg/kg. The major components were geraniol, linalool, linalool oxide, ethanol, benzyl alcohol, etc and were similar in those to the non fermented tea. A total of 79 flavor components was detected in the medium fermented tea and total contents of those were 455.6mg/kg. The major components were ethyl acetate, 3-methylbutanal, ethanol, (E)-2-hexenal, geraniol, linalooloxide. A total of 79 flavor components was detected in the Black tea and total contents of those were 680.5 mg/kg. The major components were 3-methylbutanal, ethyl acetate, geraniol, ethanol, (E)-2-hexenal, hexanal, linalooloxide. The amounts of flavor components was increased, but the amounts of aldehyde compounds was remarkably increased according to the degree of fermentation.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.16-23
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• 1986

Physico-chemical and sensory characteristics of 28 black tea samples prepared by oaring the mixing ratio of 1 kind of Korean and 9 kinds of foreign black tea were determined, and their relationship was statistically analysed. Korean black tea was found to be lower in bulk density, caffeine, theobromine, crude protein, theaflavin, thearubigin and soluble solids, and higher in Hunter L- and b- value, neutral detergent fiber, calcium and ratio of oxidized matter as compared with foreign black tea. The palatability for 8 kinds of foreign black tea was generally increased by mixing with Korean black tea. The number of black tea whose palatability were higher than that of Korean black tea was 12, which was mostly mixed black tea. Theaflavin. Hunter a-value, soluble solids of the tea infusion, and potassium of the manufactured tea were the major guiding characteristics as a result of stepwise multiple regression analysis, and about 67% of the total variations in the palatability of black tea could be explained by the regression equation formulated by the preceding 4 characteristics.

• Journal of the Korean Society of Food Culture
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• v.3 no.1
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• pp.67-76
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• 1988

With a view to making comparative study and promoting the interchange of food culture between Korea and Japan, a sensory test was given to 60 female college students (30 Koreans and as many Japanese) in order to find out differences in preference of various teas between the two nations. The findings are as follows: 1. The correlation between each specific tea and total evaluation: Significant level of high positive correlation was indicated in case of color, taste, and aftertaste by both Koreans and Japanese. In case of odor, and flavor the Koreans indicated insignificant level of nought, and the Japanese significant level of high negative correlation one. In sweetness and total evaluation the Koreans indicated positive correlation and the Japanese insignificant level of nought. 2. Comparison of preference of various teas by the Koreans and the Japanese 1) Ginseng tea A and Ginseng tea B As to Ginseng tea A and Ginseng tea B the Koreans liked odor best while the Japanese liked flavor best. In general preference the Koreans liked them better than the Japanese, and both groups indicated significant level (p <.001). 2) Black tea A: As to Black tea A the Koreans liked odor best while the Japanese taste, and in general preference the Japanese liked them better than the Koreans and both groups indicated significant level (p <.001). 3) Black tea B. As to Black tea B the Koreans liked odor best while the Japanese color, and in general preference the Japanese liked them better than the Korean and both groups indicated significant level (p <.01). 4) Coffee A. The Koreans liked odor best while the Japanese flavor, and neither of the groups indicated significant level (p <.05). 5) Coffee B. The Koreans liked color best while the Japanese flavor, and neither of the groups indicated significant level (p <.05). 6) Green tea A and Green tea B. As to Green tea A and Green tea B, the Koreans liked odor best while the Japanese taste. In general preference the Japanese liked them better than the Koreans, both indicated significant level (p <.001). 7) Malcha (a kind of traditional Green tea) Both groups liked flavor best, in general preference the Japanese liked it better than the Koreans, and both groups indicated significant level (p <.001).

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.511-516
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• 2015

On this study, we investigated the removal characteristics of residual chlorine and DBPs in tap-water during boiling. Also we investigated the releasing characteristics of essential minerals in infusion tea. While recent studies focused on removal mechanisms of harmful heavy metals in infusion tea, this study tried to suggest the way to drink tap-water healthier and safer by examining releasing mechanisms of essential minerals in infusion tea. As a result, residual chlorine(initial conc. was 0.7 mg/L) was all removed in 20 minutes after heating and DBPs (the sum of THMs, HAAs and CH) were removed up to 65%. 6 kinds of essential minerals (Ca, K, Na, Mg, S, P) were released from 5 kinds of infusion tea (barley tea, corn tea, brown rice tea, cassia seed tea, solomon's seal tea) on the market. In cassia seed tea, the amount of essential minerals released from tea showed the highest values, 9.6 mg/g, and brown rice tea was the lowest, 1.6 mg/g. Particularly, the released amounts of potassium, playing a key role in human body in maintaining normal blood pressure, cell metabolism and enzyme action, showed relatively high. Through this study, we got to know that essential minerals can be obtained up to 40% of recommended nutritional intake for Korean by boiling tap-water with infusion tea.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.256-261
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• 1999

This study was conducted to investigate the effect of barley tea with roasted grains and barley tea with a tea bag on the reduction of chlorination by-product(CBP) levels in chlorinated drinking water. Since the concentrations of six volatile compounds of eight CBPs were blow their respective detection limits after 10 minute heating, two nonvolatile CBPs dichloroacetic acid and trichloroacetic acid, and total chlorine were compared between tap water and two kinds of barley tea. No significant differences were observed in the relative changes of the amounts of the above three items, and new peaks which were not found in the original water appeared in the chromatograms of gas chromatograph/electron capture detector(GC/ECD). Thirty three organic compounds were identified in the extracts of barley tea with roasted grains, barley tea with a tea bag, corn tea, and Cassia tora seed tea which were prepared with distilled/deionized water, using gas chromatography/mass selective detection(GC/MSD). Exclusive of fatty acids, most of the compounds were aromatic compounds such as phenols, furans, and pyrroles.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.296-301
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• 2004

We focused our research interests on the characteristic of silk fabrics dyed with green tea extracts and, moreover, revealed the catechin content of silk fabrics after dyeing with Korean tea extract by measuring the residues. Three kinds of green tea samples were taken between April and May, 2003, from Bosung(southern province in South Korea), in different terms as the first corp, the second corp, and the third corp. Before and after dyeing the silk fabrics with these extracts, catechins in the residue were analyzed by HPLC. Four kinds of Catechins, such as (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EgC), (-)-epigallocatechin gallate(EgCG) were isolated from Korean green tea extracts. Catechine contents in Korean green tea leaves depend on the making process such as heating and steaming, and the younger the richer. The absorbed catechins in sillk fabrics after dyeing followed in a decreasing order of EgCG>EgC>ECG>EC. We have found a 68% uptake of EgCG, and 116.8mg/g of EgCG in the silk fabrics after dyeing with 1% Korean green tea extracts.

• The Plant Pathology Journal
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• v.15 no.5
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• pp.308-310
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• 1999

A fungus associated with gray blight on tea plant (Camellia sinensis) was identifed as Pestalotiopsis theae based on the mycological characteristics. Mycelial growth on potato dextrose agar and size and shape of conidia of P. theae were similar to those of P. longiseta, but P. theae was different from P. longiseta in the color of three median cells and the number of apical appendages. Artificial inoculation of conidial suspension or mycelial mats on the wounded leaves and shoots of healthy plants induced the same disease, respectively. The Korean native variety was relatively. The Korean native variety was relatively more resistat to P. theae than a Japanese variety‘Yabukita’which has bee recently introduced and planted in large areas of southern parts of Korea. Here, we report the report the first record of gary blight caused by P. theae on tea plant in Korea.