• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.50-54
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• 1986

The sorption characteristics of green tea were investigated at $20^{\circ}C$ with various relative humidities. Particle size showed little effect on the sorption behavior of green tea. At low relative humidities below 57%, the sorption equilibrium were easily attained, but a high relative humidities above 75%, the sorption equilibrium were not reached after 10 days. From the estimation of sorption rate at arbitrary humidities an empirical equation was obtained; $Ln{\frac{dw}{dt}}=nLn(t)+Lnc$ The monolayer moisture contents of green tea obtained by B.E.T. equation were found to be 7.87%(powder) and 7.01%(whole), respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.99-104
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• 1983

Chemical changes of major tea constituents by tea manufacture were examined by the quantitative masurements of tannin, caffeine, free sugars and total amino acid. The sample used in this experiments was fresh green and black tea leaves, green tea prepared by classical panning process and black tea prepared by commercial process. The results obtained are as follows: Compared with fresh tea leaves, tannin was increased 2% in green tea and decreased 56.5% in black tea by tea manufacture. Caffeine was increased 25.9% in green tea and decreased 3.1% in black tea. Total free sugars were decreased 78.2% and 76.7% in green tea and black tea, respectively. Total amino acids were decreased 26.1% and 18.8% in green tea and black tea, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.3
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• pp.289-295
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• 1985

This experiment aimed to find out the most effective condition of drawing method when making tea by determination of the contents of minerals infused from four kinds of green tea samples of market with its different drawing time and temperature. The mineral contents in 100 grams of raw green tea leaves revealed $1737{\sim}3000\;mg$ potassium, $178{\sim}205\;mg$ magnesium, $171{\sim}201\;mg$ calcium, $54{\sim}71\;mg$ manganese, $24{\sim}50\;mg$ sodium, $11.6{\sim}12.3\;mg$ iron, $3.4{\sim}5.3\;mg$ copper and $4.6{\sim}5.9\;mg$ zinc. The values showed some variation in their contents according to the kinds of raw green tea samples. The decreasing order of the amounts of minerals infused from the green tea samples was K, Zn, Mg, Mn, Fe, Na, Cu and Ca. The amount of minerals infused from the green tea leaves increased with increase in the drawing time and temperature. The total infusion amount of minerals was remarkably larger when drawing time was three minutes with three times repetition than when it was eight minutes without repetition at the same temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.27-30
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• 1983

This study was carried out to measure the extracted L-ascorbic acid (AsA) amounts of Korean green tea under the different extracting conditions and the measurement followed the method of 2,4-dinitrophey lhydrazine (DNP) which were reformed by Tamula. The results are summarized as follows : 1. The better he quality of green tea was, the higher the rete of AsA extraction was and the green tea having a good quality was well extracted even in low temperature. 2. The rate of AsA extraction of green tea became higher in proportion to the temperature and in the case of $80^{\circ}C$ the extracted amounts reached to 85% in the first three minutes. 3. In relation between the boiling time of test water and the extracted AsA amounts, the extracted AsA amounts was increased in proportion to the boiling time of test water.

• Journal of the Korean Society of Food Culture
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• v.4 no.2
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• pp.155-159
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• 1989

The introduction of six kinds of teas in Koryo dynasty and tea-making in domestic were investigated. The results were certified as follows. 1. Lump-tea was introduced and then also produced in domestic. 2. It is assumed that scented-tea was made from white-tea. 3. It is assumed that strong-tea and large tea were blue tea. 4. Leap-tea, green-tea were druncken at the end of Koryo dynasty.

• 중국학논총
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• no.72
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• pp.179-200
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• 2021

This paper examines the current status of the Korean tea culture industry and explores ways to restore and develop Korean tea culture by referring to the responses of the neighboring countries of China. In order for the Korean tea industry and tea culture to expand, based on a strong tea industry, high-quality tea should be created to satisfy consumers' needs, health, convenience, and reasonable prices, and effective promotion and marketing should be carried out. In addition, it is necessary to reinterpret the traditional tea house and inherit the spirit of tea.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.3
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• pp.145-163
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• 2003

Objectives : This study was performed to investigate the depigmentation effects of Aloe, Camellia sinensis and Mel. Methods : Inhibition of tyrosinase activity, melanin production & melanoma cell viability in cultured B16 melanoma cells, UV screen and cytoprotective effects on PC12 cells injured by hydrogen peroxide were measured. Results : Aloe has some inhibitory effects on tyrosinase activity, on the other hand Camellia sinensis and Mel do not have. They did not show any inhibitory effects on melanin production in melanoma cells and cytoprotective effects on PC12 cells injured by hydrogen peroxide. Aloe and Camellia sinensis have some inhibitory effects on UV screen. Conclusions : This study shows that Aloe and Camellia sinensis which were generally used for external application have some depigmentation effects. Following this, We should use them for whitening agents and the depigmentation effects of the other natural subjects which were generally used for external application should be examined.

• Journal of Haehwa Medicine
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• v.12 no.1
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• pp.11-26
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• 2003

Alzheimer's disease (AD) is characterized by amyloid deposition and associated loss of neunons in brain regions involved in learning and memory processes. Several causes of evidence support that the congnitive disturbance is closed associated with the deficit of cerebral acetylcholine neurotransmission, and the effect of carboxyl terminal 105 amino acid fragment (CT105) of the amyloid precursor protein (APP) on the gene expression of proinflammatory cytokines. We tested it on the scopolamine-induced amnesia model of the ICR mouse using the Morris water maze with repeated orally administration of 1st Green-Tea extract (200 mg/kg) and 2nd Green-Tea extract (200 mg/kg). The Green-Tea prevents impairment of learning and memory and neuronal loss in mouse models of cognitive disturbance and it demonstrated selectivity for inhibition of acetylcholinesterase (AChE). Furthermore, the repeated administration of Green-Tea, CT105-induced alzheimer's mouse model showed central cholinergic activity by ameliorates learning and memory impairment, and isolation of CD14 microglia showed significantly decreases intracellular release of the proinflammatory cytokines tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$ and reactive oxygen species (ROS). Because of its composite profile, oral therapeutic index and a prophylactic, Green-Tea is considered the better therapeutic candidate for the treatment of Alzheimer's disease.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.202-208
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• 1985

The significant chemical constituents estimating the quality of green tea were compared and analyzed in the tea shoots of native Korean tea plants. The tea shoots of different varieties among native tea plants were plucked in Waun-ri, Yongjang-ri, others in eight tea-growing places, and Yabukita, for the comparison, which is excellent Japanese variety. The contents of Yongjang-ri tea shoots were 0.55% lower in total nitrogen, 41.44mg% lower in vitamin C and 0.56% higher in tannin than the average of the other eight places. The contents of ash, caffeine and water extract showed no difference between the tea shoots. Tea shoots of Waunri had similar compositions compared with those of Yabukita and other eight places in the chemical constituents. It is considered that the tea loaves in Yongjang-ri would be different variety comparing with other eight places in the view of characters and constituents. And it is thought that tea loaves in Waun-ri would be the large leaf variety of same genealogy because tea loaves in Waun-ri was different from the other eight places in characters, but was similar to in constituents.