• 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 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 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.854-859
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• 2000

A functional yogurt was prepared from whole milk (12%) and skim milk (2%) added with green tea and mugwort tea at 3$0^{\circ}C$ for 24 hors. The yogurt product were evaluated for acid production (pH, titratable acidity), number of viable cell, viscosity, sensory property and quality-keeping property. Addition of green tea and mugwort tea remarkably accelerated acid production of yogurt. After 24 hrs incubation, titratabel acidity of green tea and mugwort tea yogurt was 1.46% and 1.62%, respectively and was higher than that (1.30%) of yogurt made with only milk. The propagation of lactic acid bacteria was not stimulated by green tea and mugwort tea and then the number of viable cell in normal (milk) yogurt green tea yogurt and mugwort tea yogurt groups, after 24 hrs incubation, was about 7.2$\times$$10^{8}$, 7.1$\times$$10^{8}$ and 7.0$\times$$10^{8}$/mL, respectively, Viscosity of green tea yogurt was slightly lower than that of milk yogurt (1,840 cps) and viscosity of mugwort tea yogurt was slightly higher than that of mild yogurt. The overall sensory score of green tea yogurt was the best of tested yogurt. When yogurt with green tea and mugwort tea was kept at 5$^{\circ}C$ for 15 days, its quality-keeping property was relatively good.

• The Korean Journal of Food And Nutrition
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• v.14 no.4
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• pp.311-316
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• 2001

This study was designed to investigate the effective ratio of healthy bread wish green tea powder. The weight. volume, and colon difference of bread with various contents of green tea powder were measured. And the picture of bread and the panel test were taken. To avoid the decrease of volume, the experiment was taken with active gluten. The weight to bread was increased and the volume was decreased significantly according to increase of green tea powder ratio. But, the volume of the group with active gluten(3%+ and 4%+) was higher than that of the group with green tea powder 2%. That is which the correction of the volute was taken by active gluten in green tea powder bread. In the result of panel test and volume measurement. addition of 3% green tea powder was appropriate, and the addition of active gluten corrected the decrease of volume. Therefore. using the green tea powder, the diversity of bread by functionality, nutritional composition. taste, color. flavor of green tea powder can be developed. This result will support the background the development of green tea bread of good quality.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1190-1196
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• 2006

This experiment was carried out to investigate the effects of Korean, Japanese and Chinese green tea on laying performance and egg quality in hens. A total of 168 "Tetran Brown" hens aged 40 weeks were assigned to 7 treatments in a completely randomized design. Each treatment had 4 replicates accommodating 6 layers per replication. The seven dietary treatments were: 1) control diet with no green tea added, 2) diet containing 1.0% Korean green tea (1.0% KGT), 3) diet containing 2.0% Korean green tea (2.0% KGT), 4) diet containing 1.0% Japanese green tea (1.0% JGT), 5) diet containing 2.0% Japanese green tea (2.0% JGT), 6) diet containing 1.0% Chinese green tea (1.0% CGT), and 7) diet containing 2.0% Chinese green tea (2.0% CGT). Egg production rate of the layers fed diets containing 1.0 or 2.0% green tea powders were significantly increased compared to that of the control (p<0.05). The egg weight of layers was significantly reduced in layers fed 1.0% CGT (p<0.05). The feed intake was significantly decreased in KGT and CGT groups at 2.0% inclusion levels (p<0.05). The egg shell thickness and shape index of JGT treatment was significantly lower than that of the control (p<0.05). There were no significant differences in albumen index, yolk index and Haugh unit of eggs for layers fed diets containing green tea powders regardless of origin (p>0.05). Green tea feeding to layers tended to reduce the overall cholesterol content of egg yolk. Particularly, 1.0 or 2.0% CGT significantly depressed the total cholesterol content of egg yolk (p<0.05). In conclusion, incorporation of 1.0 or 2.0% Korean, Japanese and Chinese green tea into layer diets regardless of origin had favorable effects on laying performance and egg quality profiles. Among the three green tea sources, the Chinese green tea powder had the highest reducing effect on cholesterol content in egg yolk.

• Journal of the Korean Home Economics Association
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• v.43 no.2
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• pp.33-40
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• 2005

This study compared the volatile aroma components in high grad Korea, Chinese and Japanese green tea. The aroma components of green tea were analyzed and compared. Aroma compared. Aroma compounds were extracted by a simultaneous distillation and extraction method using Likens and Nickerson's extraction apparatus. The concentrated aroma extract was analyzed and identified by GC and GC-MS. All the green tea samples contained relatively large amounts of terpene alcohols such as linalool, geraniol and nerolidol. The Korean green tea (A) manufactured in Cheju island contained remarkably large amounts of geraniol (9.12 %) and linalool (5.18 %). The Korean green tea (B) manufactured in Hawgae contained remarkably large amounts of geraniol (5.85 %) and linalool (5.33 %). The Korean green tea (C) manufactured in Bosung contained remarkably large amounts of linalool (7.79 %) and Z-jasmone (3.08 %). The Chinese green tea (D) manufactured in Longjing contained remarkably large amounts of geraniol (3.43 %) and linalool (2.86 %). The Japanese green tea (E) manufactured in Shizuoka contained remarkably large amoung of linalool (3.95 %) and nerolidol (2.76 %).

• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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• pp.115-124
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• 2006

From the result of pharmacetical characteristics and analysis of Green-tea extract, it could obtain some conclusions as follows. The extract experiment of Green-tea appeared about 10%-extraction ratio as semi-solid state, and after dried in freezing from Green-tea extract of semi-solid state, it obtained about 65% Green-tea extract as solid state. In the results on antimicrobial experiment of Green-tea extract, number of S-typhimurium and fungus in microbe decreased more and more according to the time passage. This phenomenon could show that Green-tea extract keeps antimicrobial effect. In the results on antioxidation experiment of Green-tea extract, DPPH scavenging activity of free radical showed that Green-tea extract appears more remarkable reduction ability than reference samples. This phenomenon means that antioxidation of Green-tea extract appears higher than Vitamin-C and BHA sample. In the results on intrument analysis, the fatty and aromatic components of aniline, acetaldehyde, acetic acid, trichloroethylene, caffeine etcs from Green-tea extract was detected with GC/MS analysis and inorganic components of Ca, Mg, Cu, Mo, Sb, Ti etcs from Green-tea extract was detected with ICP/OES analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.293-298
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• 1995

Antimicrobial effect of tea extracts from green tea(steamed, roasted), oolong tea and black tea was investigated. Minimal inhibitory concentration(MIC) of tea extraxcts against 9 well known strains of foodborne pathogenic bacteria such as the Gram positive and Gram negative bacteria was determined at 37$^{\circ}C$. Significant antimicrobial activity was observed in the steamed green tea and the roasted green tea of the water-soluble fraciton, and the steamed green tea of the methanol-soluble fraction, and the steamed green tea, roasted green tea and the oolong tea of the crude catechin fraction. The MIC of these extracts against B. subtillis were 700$\mu\textrm{g}$/ml, 500$\mu\textrm{g}$/ml and 120 $\mu\textrm{g}$/ml, respectively. The crude catechin fraction possessed greater antimicrobial activity than did the other fractions. Among tea extracts, extracts of steamed green tea, roasted green tea and oolong tea showed higher antimicrobial activity than them of black tea. The MIC of the crude catechin fraction obtained from tea extracts against Gram-positive bacteria such as M. Iuteus, B. subtillis and S. mutans were 30~50$\mu\textrm{g}$/ml, 120~240$\mu\textrm{g}$/ml and 120~180$\mu\textrm{g}$/ml, and against Gram-negative bacteri such as e. aerogenes and V. parahaemolyticus were 50~60$\mu\textrm{g}$/ml and 60~70$\mu\textrm{g}$/ml in the broth medium, respectively. Especially, the MIC to Streptococcus mutans which has known as a causative bacteria of a decayed tooth were 120$\mu\textrm{g}$/ml, 140$\mu\textrm{g}$/ml, 180$\mu\textrm{g}$/ml and above 1,000$\mu\textrm{g}$/ml in steamed green tea, roasted green tea, oolong tea and black tea, respectively. Tea extracts had strong growth inhibition activity against foodborne pathogenic and dental bacteria.

• The Korean Journal of Community Living Science
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• v.19 no.1
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• pp.55-61
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• 2008

This study was conducted to compare the nutrient and chemical contents of traditional Chungtaejeon tea with that of green tea which was harvested in Jangheung, Jeonnam district. Vitamin C, amino acids and total nitrogen contents of Chungtaejeon tea were lower than that of green tea by 0.30, 2.30 and 4.20g/100g, respectively. The tannin, caffeine, reducing sugar and chlorophyll contents in Chungtaejeon tea were the same as those in green tea. Comparing catechin contents, catechin (C), epicatechin (EC), and epigallocatechin (EGC) in Chungtaejeon tea were lower than those of green tea. However, gallocatechin (GC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and catechin gallate (CG) showed no significant difference between Chungtaejeon tea and green tea. The flavonoid contents of Chungtaejeon tea and green tea showed higher quercetin and kaempferol contents in green tea, and higher myricetin content in Chungtaejeon tea. The measured amino acid contents for threonine and aspartic acid were lower, and for glutamic acid were higher in Chungtaejeon tea compared with those in green tea. However, free amino acid content in Chungtaejeon tea and green tea showed no significant difference. Potassium and magnesium contents in Chungtaejeon tea were lower compared to green tea but no significant difference was found for iron, manganese or calcium contents when comparing the two teas.