• Food Science and Preservation
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• v.10 no.2
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• pp.241-245
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• 2003

To develope tea-fungus beverage(TB), media added various kinds of ingredients including black tea, persimmon leave tea, pine needle, mugwort mycelia and fruiting body of Cordyceps spp. were prepared fur fermentation. Tea-fungus beverage(TB) was prepared with tea-fungus by fermentation for 2 weeks at 30 $^{\circ}C$. Functional properties of antibacterial activity, electron donating ability and nitrite scavenging ability were investigated in tea-fungus beverage(TB) and 5 times diluted tea-fungus beverage(DTB). Antibacterial activity against pathogenic E. coli and S. aureus was excellent in TB added pine needle, mycelia and fruiting body of Cordyceps japonioa while no activity in TB added persimmon leave tea. Electron donating ability of TB were ranged from 41％ to 87% in TB and were ranged from 11% to 63％ in DFB, high ability was in TB and DTB added pine needle and persimmon leave tea, while low ability in FB and DTB added mycelia and fruiting body of C. militaris. Nitrite scavenging ability was 63% in TB added black tea and 44% in TB added persimmon leave tea. Other ingredients added TB had weak nitrite scavenging ability.

• Journal of the Korean Society of Food Culture
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• v.24 no.2
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• pp.181-190
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• 2009

The purpose of this study was to investigate individuals' perceptions toward green tea and green tea cafes according to their usage of green tea cafes, gender, and marital status. The survey was conducted online and completed by 200 respondents who had been to green tea cafes and by 200 respondents who had not. The visitors of green tea cafes had more positive perceptions regarding the atmosphere, familiar taste, good quality of raw foods, freshness of foods, good service, excellent taste, and menu variety of green tea cafes. Males perceived green tea as 'good for health' more than the females. There was no difference in the perception of green tea cafes by marital status. Regarding a popularization plan for green tea cafes, the customers felt more need for a tea sommelier than the non-customers, and females versus males felt stronger about having a tea sommelier that would provide opportunities to taste various tea products and develop a green tea menu that considered nutrition and health. Unmarried respondents felt a greater necessity for having a place with a comfortable environment, tasting a variety of tea products, and having a chance to experience tea culture. When selecting a green tea cafe, the quality of the food and cleanliness of the cafe were considered to be most important. The implications of the data are discussed.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.165-169
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• 2000

Kombucha beverages were made from sweetened tea by Oriental, European and Tibetan tea fungus starters. The hot water extracts o green tea, black tea, Gugija and Omija were mixed with white and/or brown sugar, and were fermented under a static culture at 3$0^{\circ}C$. Titrable acidity, pH, color and cellulose production in kombucha beverages were evaluated. All tea fungus starters showed a higher acid production in green/black tea extracts rather than Gugija and Omija extracts. In green/black tea extracts Oriental tea fungus produced a kombucha beverage with a higher titrable acidity and lower pH than those of European and Tibetan tea fungus starters. By the static fermentation of green/black tea extract for 18 days, Oriental, Tibetan and European tea fungus starters produced cellulose pellicles of 0.43g, 0.16g, and 0.19 g (dry weight) on the top in the culture, respectively. As a mother starter, the cellulose pellicle was more efficient in acid production compared with tea fungus broth. Oriental/Tibetan mixed tea fungus showed the best acid production in the green/black tea extract supplemented with brown sugar.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.932-938
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• 2009

Browning of tea infusion is an obstructive factor influencing shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea infusion were investigated. It was shown that both elevated temperature and illumination led to the browning of green tea infusion, but temperature had greater effect on infusion color and level of catechins than illumination. The levels of unoxidized catechins such as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epicatechin (EC), and total catechins remaining in the tea infusion were significantly correlated to color parameters of the tea infusion. Sodium ascorbate inhibited the infusion browning by suppressing the oxidation of tea catechins and it is considered to be a more suitable preservative for prolonging shelf life of ready-to-drink green tea than ascorbic acid because it has less effect on tea taste. The effects of temperature and illumination on the epimerization of catechins were also discussed.

• Food Science and Preservation
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• v.7 no.1
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• pp.117-123
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• 2000

In order to promote the utilization of Hovenia dulcis leaf as food, leaf tea was nanufactured and its physicochemical properties were examined. Aong proximate composiotns of Hovenia dulcis leaf tea were found in both fermented tea and roasted tea the higher contents of total sugar and crude protein. In minerals component of fermented tea and roasted tea, potassium (K) was the most high amounts of 11,560.6 ppm and 11,084.6 ppm, respectively. The highest contents of free sugar in both teas were mainly consisted of sucrose, the amounts of sucrose showed 1.47% and 1.94% . In case of organic acids, oxalic acid and citric acid were revealed 631.26mg% and 660.05mg%, respectively. The highest contents of total amino acid in fermented tea and roasted tea were 812.01mg% and 709.72mg% of glutamic acid. the fatty acids of fermented tea and roasted tea were mainly composed of 40.18% of linolenic acid and 26.92% of palmitic acid, respectively. The major volatile compounds of fermented tea and roasted tea were composed of 3, 7, 11, 15-tertramethyl-2-hexadecen-1-ol and methyl palmitate and the amounts of those showed 290.1ppm and 472.97 ppm, respectively. The tannins of fermented tea and roasted tea were 1.02% and 1.26% , as the extraction steps increased the tannin contents decreased. In Hunter's color values of tea extract L and b values decreased , while a value of those increased as the extraction steps were repeated.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.4
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• pp.285-296
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• 2016

This study was conducted to obtain a better understanding of American green tea consumers for increasing Korean green tea sales in the US market. In doing so, this study investigated green tea choice attributes of US consumers and segmented them based upon their perceptions about important attributes of green tea. A factor-cluster segmentation approach was used for this study. An exploratory factor analysis identified five green tea choice motives: 'Sensory', 'Diet', 'Price', 'Health', and 'Brand'. Based upon these five choice attributes, cluster analyses classified all respondents into four homogeneous subgroups: 'Highly motivated', 'Taste/Price oriented', 'Health oriented', and 'Brand oriented'. Cross-tab tests proved that green tea consumption and purchasing patterns were significantly different among the four clusters. In particular, two cluster groups representing 'Highly motivated' and 'Health oriented' groups were found to offer the most utility for further American green tea market segmentation research. Findings show that American green tea consumers include a wide range of age groups and they usually buy green tea at grocery markets. Managerial implications for all cluster groups based upon their unique characteristics are provided. Korean green tea companies can apply these findings in order to develop more effective and efficient marketing strategies to attract American consumers to buy more Korean green tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.160-168
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• 1995

Desmutagenicities against 2-amino-1-methyl-6-phenylimidazo[4, 5-b] pyridine(PhIP) and 2-amino-3, 8-dimethylimidazo[4, 5-f]quinoxaline(MelQx) of tea extracts (steamed green tea, roasted green tea, oolong tea and black tea) were investigated. All the fractions obtained from tea extracts showed strong desmutagenic activity against PhIP and MeIQx toward S. typhimurium TA 98 in the presence of the S-9 mix. The crude catechin fraction exhibited the strongest desmutagenic activity. Among these tea extracts, black tea especially exhibited the strongest desmutagenic activity and the activity was 70.9~91.0% against PhIP and 92.2~98.8% against MelQx at a concentration(0.5~1.0mg/plate) for drinking. The activity of authentic catechins of (-)-EGC, (-)-EGCg, (-)-ECg and (-)-EC were 79.5%, 60.2%, 46.1% and 43.5% against PhIP, and were 52.3%, 11.6%, 8.2% and 22.1% against MelQx by addition of 1.0mg/plate, respectively. The desmutagenic activity was supposedly due to the (-)-EGCg, (-)-EGC and (-)-EC in tea polyphenols, and the browning materials. The desmutagenicity was stronger when mutagens were preincubated with S-9 mix after reaciton with black tea extracts than when preincubated with them after reaction with S-9 mix. The desmutagenicity of tea extracts was rather expressed by reacting directly with mutagens than by deactivating the activated forms of mutagens.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.17-22
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• 1998

To investigate the detoxificative effect of tea, five kinds of tea(mulberry, anaerobic treated mulberry, green, barly tea and corm tea) were selected and determined their dotoxication activities for Cd and Pb in drinking water. The effect of tea on the removal of Cd and Pb were increased proportionally to the contents of teas. Anaerobic treated mulberry leaf tea showed stronger detoxication activity than the others. In drinking water contaminated with Cd, the removal effect of Cd was high 27% by anaerobic treated mulberry leaf tea and 14% by mulberry leaf tea as compared to green tea. Also, in drinking water with Pb, the removal effect of anaerobic treated mulberry leaf tea was the best among five kinds of tea. Pretreatment method on the removal effect of Cd was better than post-treatment method in the treatment method.

• Journal of Nutrition and Health
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• v.5 no.3
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• pp.109-125
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• 1972

According to the Sam-guk Sa-gi (History of three Kingdoms: Silla, Koguryo and Paeckje) tea was first brought into Korea by Kim Tae-ryeum, a diplomat, in 828 A.D. during the reign of king Hung-dot of Silla, and planted on the hill of Mt. Chi-ri. Afterwards, the tea trees were transplanted and cultivated by Buddists in many Buddist temples in southern provinces during the Silla and Koryo dynasties. People took much delight in drinking green tea, and specially the kings, buddist monks and nobilities of Silla and Koryo enjoyed drinking green tea. And eventually, the green tea became an indispensable part in all important ceremonies during the Koryo dynasty. After the Yi dynasty came into being, the dualistic philosophy of China was introduced and respected while buddist temples declined as a result of strong oppression by the ruling class. While temples were declined, the practice of drinking green tea was also declined. Nowadays we find many tea plants grow wild, which are seemed to be planted around buddist temples during the Koryo dynasty. Today, Korean people do not drink home made green tea. Instead, they like to take coffee, black tea and other tea products imported from foreign countries. Aa a result, Korea had to pay $ 520 thousand in 1969 to import foreign made tea and coffee. The natural conditions of southern provinces of Korea are very suitable in cultivating tea plants. If we develope the skill in producing good quality tea in Korea, we would be able to save the foreign exchanges that are being spent for importing foreign made tea products, and at the same time, we would be able to export our green tea to overseas. The quality of Korean green tea is as good as that of Japanese green tea. Green tea contains vitamin C while coffee and black tea do not contain it.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.29-44
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• 1995

A model experiment on the pair midwater trawl net applicable to 800 PS class Korean pair bottom trawlers was carried out in the special-prepared experimental thank. the tank was prepared as a reverse trapezoid shape in its vertical section by digging out flat soil. The dimension of the tank showed the 9.6 W$\times$43.0 L(m) of the upper fringe and the 4.8 W$\times$38.0 L(m) of the bottom with 3.0m in depth. The depth of water was maintained 2.7m during experiment. The model net was prepared based on the Tauti's similarity law of fishing gear in 1/30 scale considering the dimension of the experimental tank. Mouth performance of the model net during towing were determined by the photographs taken in front of the net mouth with the combinations of towing velocity, warp length and distance between paired boats. The results obtained can be summarized as follows: 1. Vertical opening of the model nets A and B was varied in the range of 0.18~0.88 m and 0.21~0.78 m (which can be converted into 5.4~26.4m and 6.3~23.4 m in the full-scale net) respectively, and was varied predominantly by towing speed. Vertical opening (H which is appendixed m for the model net. f for the full-scale net. A and B for the types of the model net) can be expressed as the function of towing velocity$V_t$as in the model net $V_t$ : m/ sec)$H_{mA}$=1.67$e^{-1.65V_t}$ $H_{mB}$=1.15$e^{-1.13V_t}$, in the full-scale net ($V_t$ : k't) $H_{fA}$=50.27$e^-0.37V_t$ $H_{fB}$=34.46$e^{-0.26Vt}$. 2. Horizontal opening of the model nets An and b was varied in the range of 1.03~1.54m and 1.04~1.55 m (which can be converted into 30.9~46.2 m and 31.2~46.5m in the full-scale net) respectively, and was varied predominantly by distance between paired boats. Horizontal opening (W, appendixes are as same as the former) an be expressed as the function of distance between paired boats $D_b$as in the model net $W_{mA}$=0.69+0.09$D_b$ $W{mB}$=0.73+0.09$D_b$, in the full-scale net $W_{fA}$=20.81+0.09$D_b$ $W_{fB}$=22.11+0.09$D_b$ 3. Net opening area of the model net A and B was varied in the range of 0.28~1.04 $m^2$ and 0.33~0.94$m^2$(which can be converted into 252~936$m^2$ and 297~846$m^2$ in the full-scale net) respectively, and was varied predominantly by towing velocity. Net opening area ($S$, appendixes are as same as the former) van be expressed as the function of towing velocity$V_t$ as in the model net $v_t$ : m/sec) $S_{Ma}$=2.01$e^{-1.54V_T}$ $S_{mA}$=1.40$e^{-1.65V_t}$, in the full-scale net ($V_t$ : k't) $S_{fA}$=1.807$e^-0.35V_t$ $S_{fA}$=1.265$e^{-0.24V_t}$. 4. Filtering volume of the model nets A and B was varied in the range of 0.32~0.55 $m^3$ and 0.37~0.55$m^3$(which can be converted into 8.640~14.850 $m^3$ and 9.990~14.850$m3$in the full~scale net) respectively, and was predominantly varied by towing speed. filtering volume of the model net-A showed the maximum at the towing speed 0.69 m/sec(3 k't in the full-scale net), compared with that of the model net B showed at 0.92 m/sec(4 k't in the full-scale net).