• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.107-113
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• 2006

These studies were carried out to investigate the quality of green tea processed by different pan-firing hand rolling and to select the best conditions during the procedure of green tea processing the results were as follows. At harvestion tea plant leaf, tea plants had 4 leaves. each leaf size was 7.5 cm'$\square$2.6 cm, and weight of 100 buds 46.6 g. The increase of pan-fired time decreased in the moisture content and yield of green tea. After processing green tea, 5 times pan-fired one had much more contents of total nitrogen (T-N:5.31%), caffeine (2.00%) and total amino acid (T.A.A. : 3,046 mg%) and less content of tannin (13.41%) than the other treatments. but 3 times pan-fired one had the highest contents of vitamin C (204.3 mg%) and chlorophyll (365.0 mg%) among three kinds pan-firing method. Sixteen kinds of free amino acid including theanine as a good taste component of pan-fired green tea were isolated and measured by HPLC. Free amino acid (FAA) contents were in the range of $2,683{\sim}2,925$ mg% and among various pan-firing methods, 5 tims pan-fired one had the highest content of F.A.A. Among these free amino acids, theanine occupied as much as $56.4{\sim}61.3%$ of F.A.A. Lightness, yellowness and redness of 5 times pan-fired green tea were middle value among three different treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 5 times pan-fired green tea was considered to be the best level as pan-firing times of green tea processing.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.217-224
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• 1997

The significant chemical components estimating the quality of green tea were compared and analyzed in the shoots of Korean native tea plants. The results are summarized as follows. The contents of total nitrogen in tea leaves were in range of $3.59{\sim}4.89%$, and the tea plants grown wildly in Bosong Daewonsa, Hwasun Ssangbongsa, Shunchun Changchun-ri, Hadong Ssanggyesa. and the cultivated tea plants in Kangjin Jangwon Sanup had higher contents of total nitrogen. The contents of tannin ranged from 12.5 to 18.3%. The contents of tannin of Kuryoi Chonunsa (18.3%), Kangjin Baekryonsa (16.7%) and Naju Bulhoisa (16.4%) were higher than those of Yangkwang Chonma-ri (12.5%), Hampyong Yongam-ri (12.7%) and Yosu Udu-ri (12.8%). The contents of caffeine were in range of $2.21{\sim}3.11%$. The contents of caffeine of Kwangju Shamae Dawon (3.11%), Kangjin Jangwon Sanup (2.94%) and Shunchun Changchun-ri(2.87%) were higher than those of Tamyang Yanggak-ri(2.21%), Yosu Udu-ri(2.23%) and Kuryoi Hwaomsa (2.23%). The contents of vit. C were in range of $167.9{\sim}223.5mg/100g$. The contents of vit. C of Changsong Oshan-ri (167.9mg/100g), Shunchun Shongkwangsa (185.6mg/100g) and Yongkwang Chonma-ri (185.8mg/100g) were lower than those of Kwangju Shamae Dawon (291.5mg/100g), Kangjin Jangwon Sanup (271.8mg/100g) and Shunchun Changchun-ri (269.5mg/100g). The contents of chlorophyll were in range of $187.4{\sim}332.7mg/100g$, and the mean contents were in range of 242.0mg/100g. The contents of total amino acids were in range of $1,888{\sim}2,500mg/100g$. The content of total amino acid at Kangjin Jangwon Sanup was the highest as 2,500mg/100g, and that of Shunchon Shongkwangsa was the lowest as 1,888mg/100g. Results of this study suggest that the native tea plants naturally grown at Bosong Daewonsa, Hwasun Ssangbongsa, Shunchun Changchun-ri, Hadong Ssanggyesa, and the cultivated tea plants at Kangjin Jangwon Sanup show excellent quality in terms of abundance of total nitrogen and total amino acids, and less contents of tannin.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.33-38
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• 2010

This study was conducted to compare the physicochemical properties of powdered green teas produced in Korea and Japan including particle size, color, chlorophyll, caffeine and theanine. The average particle size of Korean powered green tea ($14.63-25.39\;{\mu}m$) was similar to that of Japanese powdered green tea ($15.46-21.02\;{\mu}m$). The surface color of shade-cultivated Haenam Green Tea (HN-1) had the highest negative 'a' value, which represents 'green' color. When the TCD (total color difference value) was measured in the samples, HN-1 was most similar to the premium powdered green tea of Japan (JA-1). Domestic shade-cultivated powdered green teas had 1.5-2 times greater chlorophyll content than powdered green teas produced from plants that were not cultivated in the shade. The presence of chlorophyll a resulted in a higher intensity of green color than the presence of chlorophyll b. A significant negative correlation was also observed between the color and the chlorophyll a, chlorophyll b and total chlorophyll contents. Specifically, chlorophyll a had the greatest impact on the green color of powdered green tea. The content of catechins, caffeine and theanine in Korean powdered green teas ranged from 14.679-20.128, 1.496-3.237 and 0.926-1.977 g/100 g, respectively. The caffeine and theanine contents were high in shade-cultivated powdered green teas. Based on the above results, domestic powdered green teas cultivated under shaded conditions had a quality similar to that of medium-quality green teas produced in Japan, and the overall quality of Korean powdered green tea was poorer than that of Japanese powdered green tea.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.238-245
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• 1998

The reasonable level of nitrogen fertilizer is a key factor to reduce environmental contamination as well as to increase crop yield and quality. The treatments are $N=42kg\;10a^{-1}$, $N=48kg\;10a^{-1}$, $N=54kg\;10a^{-1}$. $N=60kg\;10a^{-1}$. $N=72kg\;10a^{-1}$ and $N=150kg\;10a^{-1}$. Analytical results of yield and quality of tea leaves harvested the second time are summarized as follows: The soil of experimental field was higher in organic matter($49.9g\;kg^{-1}$) and available phosphate($937mg\;kg^{-1}$) compared to the general field but lower in pH(5.07) compared to the general field. When the amount of nitrogen fertilizer application was raised, the yield of tea leaves, the content of nitrogen, total free amino acids, caffeine and chlorophyll increased: however, the yield of tea leaves increased to excessive levels. On the other hand, the increased level of nitrogen fertilizer did not show any difference in the contents of vitamin C and tannin. Eleven kinds of amino acids were isolated from second harvested leaves of tea where the content of theanine occupied over 50%, and content of $665{\sim}763mg\;100g^{-1}$. The contents of fatty acids and catechin did not show correlation with application level of nitrogen fertilizer. The content of fatty acid was produced $1,742{\sim}2,643mg\;100g^{-1}$, and content of catechin was produced 12.47~13.54%. In scoring test, $N=60kg\;10a^{-1}$ treatment was 0.5~6.0 point higher compared to other treatments. Consequently, $N=60kg\;10a^{-1}$ is considered to be the best level of nitrogen fertilizer in terms of decreased environmental contamination as well as to increase crop yield and quality.

• Food Science and Preservation
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• v.11 no.2
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• pp.175-181
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• 2004

As a foundational study for notifing excellence of persimmon leaves tea, the chemical component and antioxidant activity were investigated in persimmon leaves from Dungsi, Gabjubaekmok, Weulhasi and Cheongdobansi and green tea leaves. Total sugar contents in all persimmon leaves more higher than that of green tea leaves, and the highest free sugar contained in persimmon and green tea leaves was sucrose. Free sugars present in persimmon and green tea leaves were composed of sucrose, glucose, fructose, maltose and xylose. Sucrose and fructose took more than 70% of total sugar contents. 31∼32 kinds of amino acid were detected in persimmon leaves and 35 kinds in green tea leaves. And total amino acids contained in persimmon leaves were Dungsi, Gabjubaekmok, Weulhasi and Cheongdobansi, respectively 60.40 nmol/${\mu}$L, 53.21 nmol/${\mu}$L, 52.29 nmol/${\mu}$L and 47.58 nmol/${\mu}$L. Total amino acid contents in green tea leaves was the most abundant of all as 114.72 nmol/${\mu}$L. The contents of vitamin C in persimmon and green tea leaves were in the range of 0.015∼0.089% and 0.01%, respectively. Vitamin C was significant higher content in the persimmon leaves than in green tea leaves. Caffeine was not detected in all persimmon leaves, but the caffeine content of green tea leaves was 6.63 mg/l00 g. The content of catechin was showed in the orders of Cheongdobansi, Gabjubaekmok, Weulhasi, Dungsi and green tea leaves; 0.35%, 0.34%, 0.24%, 0.18% and 0.07%, respectively. The contents of gallic acid in Dungsi and Gabjubaekmok were 0.32% and 0.20%. That of green tea was 1.41%, it was the highest content in all samples. The content of calcium in Chengdobansi was most abundant in all samples as 3516.14 ppm, it was 4∼5 times as that of green tea leaves. Flavor component pattern among persimmon leaves was similar, but that of green tea leaves was different. The IC50(${\mu}$g) value of Dungsi, Weulhasi, Gabjubaekmok, Cheongdobansi and green tea were 64.5, 42.0, 47.0, 64.0 and 19.0 respectively.

• Korean journal of food and cookery science
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• v.23 no.6
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• pp.954-960
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• 2007

The study was designed to determine optimum extraction conditions, by the factorial design of 3 variables and 3 levels using an a RSM program. To determine the optimal conditions for the extraction of black tea with chamomile, the experimental design was applied. The independent factors were the extraction temperature ($60^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$), extraction time (2 min, 4 min, 6 min), and chamomile addition (0.3%, 1.0%, 1.7%). By the RSM (response surface methodology) analysis of the black tea with chamomile extraction, we found that the extraction temperature greatly affected the extraction yield, brix, pH, and reducing sugar, caffeine, theobromine and theophillin contents. The optimum extraction time, temperature, and chamomile content were 4 min, $90^{\circ}C$, and $1.6{\sim}1.7%$, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.1
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• pp.107-112
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• 2006

This study analyzed the changes of chlorophyll and ascorbic acid contents according to the extraction temperatures and the number of soakings using five kinds of Korean and Japanese green tea(3 kinds of green tea and 2 kinds of tea bag) which were obtained from local markets in Korea and Japan. The findings are as follows: 1. The chlorophyll contents of Japanese green tea were $2\sim3$ times higher than those of Korean green tea. 2. The chlorophyll contents of Korean green tea in high and middle grades were increased with increasing temperature $(80>70>60^{\circ}C)$ but the contents in low grade were increased with decreasing temperature. The contents of chlorophyll in Japanese green tea were almost similar in low, middle and high grades. 3. Ascorbic acid content was higher in low grade Korean green tea but it was higher in high and middle grades of Japanese green tea. Chlorophyll contents of Japanese green tea were higher than those of Korean green tea but ascorbic acid contents of Korean green tea were higher than those of Japanese green tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1025-1029
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• 2008

Fresh green tea leaf extracts were prepared by different enzyme treatment conditions, such as concentration, treating time and treating temperature using complex enzyme, Rapidase TF, and then extracted for 30 min at $80^{\circ}C$ to investigate their physicochemical properties. The results showed that free sugar content in every sample tended to increase, especially glucose content was increased up to 7.25 times compared to the control. Total amino acid was barely affected by the enzyme treatment and caffeine content was increased with reaction temperature. Total polyphenol and total catechin content was increased according to the amount of enzyme added and reaction temperature. Regardless of enzyme treatment conditions, composition of catechins were epigallocatechin, epicatechin, epicatechin gallate and epigallocatechin gallate by descending order of the content. Gallic acid content increased up to 0.04% and $45^{\circ}C$ with no further significant changes thereafter. From the results above, we could conclude that a simple and new method to extract green tea materials directly from fresh green tea leaves with improved extract ratio may be introduced by adding $0.08{\sim}0.1%$ of Rapidase TF to heat treated fresh green tea leaves and keeping temperature at $37{\sim}45^{\circ}C$ for $180{\sim}240\;min$ in order to skip existing complicated procedures.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.160-166
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• 2000

The reasonable level of nitrogen fertilizer of Gyokuro tea which is producted fresh leaves plucked from shade tea plants is a key factor to increase crop yield and quality. Nitrogen were applied at the level to 60, 80, 100 and $120kg\;10a^{-1}$. Analytical results of yield and quality of Gyokuro tea are summarized as follows : The soil fertility of experimental field was higher in organic matter($59.8g\;kg^{-1}$) and available phosphate($1,285mg\;kg^{-1}$), but lower in pH(4.79) compared to the common field. As the amount of nitrogen fertilizer application was increased to $80kg\;10a^{-1}$, the yield of tea leaves, the content of total nitrogen, total amino acid, caffeine and chlorophyll were increased. However, the yield of tea leaves was not increased above $100kg\;10a^{-1}$ and the increased level of nitrogen fertilizer did not show any different in the content of tannin and vitamin C. When the amount of nitrogen fertilizer application was raised, the content of thiamine and arginine increased, but the content of aspartic acid, serine and glutamic acid decreased. The content of fatty acid was produced $2.850{\sim}3.012mg\;100g^{-1}$ Especially, the content of oleic acid, linoleic acid and linolenic acid was higher at the level of $80kg\;10a^{-1}$ application than other treatments. As nitrogen was applied at $80kg\;10a^{-1}$, sensory score was 0.2~4.6 point higher than other treatments. Consequently, $80kg\;10a^{-1}$ is considered to be the best level of nitrogen fertilizer both quality and crop yield.

• YAKHAK HOEJI
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• v.58 no.4
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• pp.245-249
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• 2014

Murrayafoline-A (1-methoxy-3-methylcarbazole) is a monomeric carbazole alkaloid found in Murraya euchrestifolia HAYATA and Glycosmis stenocarpa. We have recently shown that murrayafoline-A has positive inotropic effect in isolated rat ventricular myocytes. To know possible mechanisms for the positive inotropic effect of murrayafoline-A we examined the effects of murrayafoline-A on in situ behavior of cardiac $Ca^{2+}$ release units ('$Ca^{2+}$ sparks') and sarcoplasmic reticulum (SR) $Ca^{2+}$ loading using confocal $Ca^{2+}$ imaging method in single rat ventricular myocytes. Murrayafoline-A significantly increased the frequency (events/($10^3{\mu}m^2{\cdot}s$)) of $Ca^{2+}$ sparks in a concentration-dependent manner, with an $EC_{50}$ of $28{\pm}6.4{\mu}M$ and a maximal ~twofold change. The $Ca^{2+}$ content in the SR, measured as caffeine (10 mM)-induced $Ca^{2+}$ transient, was significantly increased by murrayafoline-A (${\approx}$116% and ${\approx}$123% of control at 25 and 100 ${\mu}M$, respectively). In addition, murrayafoline-A significantly increased the fractional $Ca^{2+}$ release, suggesting increase in the efficacy of $Ca^{2+}$ release at given SR $Ca^{2+}$ loading. These results suggest that murrayafoline-A may enhance contractility via increase in $Ca^{2+}$ release from the SR through the ryanodine receptors in ventricular myocytes.