• Journal of the Korean Society of Food Culture
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• v.21 no.1
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• pp.8-16
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• 2006

This study was performed by questionnaire to investigate the preference and intake frequency of Korean traditional commercial beverages. The subjects were consisted of 320 participants in Daegu and Kyungpook area. 'Chain market' scored 49.4% as purchasing place of traditional beverages. 'Tea bag' scored 31.6% as the favorite package of traditional beverages. On the reasons of drinking traditional beverage 'good for health' scored the highest with 31.3% respondents, followed by 'good smell' with 14.4%. Coffee and traditional tea were the choice of beverage after having a rich meal and on occasion of entertaining guests. The favorite foods in ordinary days were 'tea', 'alcohol', 'ice cream', 'nuts' and 'cookie'. More than thirty percent of the respondents, both male and female, raised the need of improvement in taste of traditional beverage. In the intake frequency, Korea traditional beverages obtained 1.80 points as a whole. 'Green tea' scored highest(3.40points) while 'mulberry-leaf tea' received the lowest score of 1.31 points. The preferred Korean traditional drinks were 'greed tea', 'shick hae', 'citron tea', 'misitgaru', 'maesil tea', 'rice tea' in the order. On the other hand, the preference for 'mulberry-leaf tea', 'boxthom tea', 'ginger tea', 'chrysanthemum tea' and 'omija tea' was very low. The people who are on twenties preferred 'shick hae', 'honey tea', 'citron tea', 'black tea' and 'misitgaru' more than the other generation.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.64-76
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• 2013

In this study, eco-friendly hybrid composite boards were manufactured from green tea, three kinds of charcoals and wood fiber for developing interior materials to reinforce the strength performances and the functionalities in addition to performances of the green tea-wood fiber hybrid boards. The effects for the kind and the component ratio of raw materials on mechanical properties were investigated. Bending strength performances of hybrid composite boards were highest in the hybrid composite boards composed of green tea, fine charcoal and wood fiber on average. However, the difference caused by the kind of charcoals was not large. These values were was markedly improved than those of green tea - wood fiber hybrid composite boards reported in previous researches. And it was found that the bending strength performance decreased with increasing component ratios of green tea and charcoals. The difference between urea resins used as the binder showed the higher value in hybrid composite boards using $E_1$ grade urea resin than in those using $E_0$ grade urea resin, but the difference between hybrid composite boards manufactured by both resins decreased markedly than the green tea - wood fiber hybrid composite boards reported in previous research. The internal bond strength of hybrid composite boards was in the order of hybrid composite boards with fine charcoal, activated charcoal and black charcoal, and it was found that the hybrid composite boards with fine charcoal had a similar values to control boards composed of only wood fiber.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.95-101
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• 2012

Nutritional components of Ojuk leaf tea and Ojuk shoot tea prepared from the leaves and shoots of black bamboo (Phyllostachys nigra Munro) by tea manufacturing process were evaluated. In addition, the extraction yield of water soluble components from these teas in the general tea brewing condition (water extraction in $80^{\circ}C$ for 10 min.) and the contents of polyphenol and flavonoid were compared with not only the dried raw materials, but also green tea and mate tea. Finally, offline and online scavenging activities against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and di(phenyl)-(2,4,6 trinitrophenyl)iminoazanium free radicals were investigated to evaluate the antioxidant activity and explore the components showing ABTS free radical scavenging activity from tea infusion. These results demonstrated that these teas from black bamboo contain various nutritional components and can be used as traditional tea beneficial to human health.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2005.10a
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• pp.113-113
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• 2005

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.170-179
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• 2017

Tea is the most popular beverage in the world. In fact, there are mainly three different kinds of tea (Green tea, black tea, and post-fermented tea). Post-fermented tea is produced by the microbial fermentation process using sun-dried green tea leaves (Camellia sinensis) as the raw material. Chungtaejeon was a traditional tea introduced in the age of the ancient three states and is the only "Ddeok-cha or Don-cha" culture in the world that survived on the southwestern shore of Republic of Korea. In this study, the structures of the bacterial community involved in the production of oriental traditional post-fermented tea (Chungtaejeon) were investigated using 16S rRNA gene analysis. The 16S rRNA gene analysis of dominant microbial bacteria in post-fermented tea confirmed the presence of Pantoea sp., and Klebsiella oxytoca. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the post-fermented tea was ${\gamma}$-proteobacteria. As a result of the microbial community size analysis, it was confirmed that the size of the microbial communities of Chungtaejeon was the largest compared to other teas

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2557-2560
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• 2010

To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

• Journal of the Korean Society of Food Culture
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• v.27 no.5
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• pp.512-520
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• 2012

This study investigated the sensory characteristics of adlay tea favorably consumed by Korean consumers and analyzed the drivers behind for liking or disliking adlay tea. Six adlay tea products showing the highest market share in South Korea were selected. Sensory properties of the six products were analyzed using generic descriptive analysis. Among these, four products were further selected for consumer taste acceptance test. Sensory lexicons of adlay tea were developed by trained panelists, and the sensory characteristics of each adlay tea product were measured based on the perceived intensities of these attributes elicited from the samples. In the consumer taste acceptance test, frequent tea and coffee drinkers participated. Consumers rated the acceptance of each tea product on a 9-point hedonic scale and evaluated the reasons for liking or disliking each product based on the check-all-that-apply method. Analysis of Variance, principal component analysis, frequency analysis, and correspondence analysis were utilized for statistical analysis. Twenty sensory attributes were developed in order to characterize the six adlay tea products. The results of the descriptive analysis showed that attributes such as viscosity, black soybean flavor, goso flavor, peanut flavor, seaweed flavor, green, and presence of chunks were key factors differentiating the adlay tea products. In the consumer taste test, roasted flavor, goso flavor, peanut flavor, and presence of chunks were positive drivers for liking the adlay tea products, whereas seaweed and green flavors were negative attributes that drove consumers away.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.132-139
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• 2016

The purpose of this study was to investigate the contents of antioxidant compounds and antioxidant activities in teas. A total of 99 teas were tested for their antioxidant activities based on their ability to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. Antioxidant activity was expressed as mg of ascorbic acid equivalents per 100 g tea sample (L-ascorbic acid equivalent antioxidant capacity, AEAC) and was expressed as mg per 1 serving size (free radical scavenging activity, $FSC_{50}$). The total polyphenol contents of the extracts was quantified using the Folin-Ciocalteu method and the total flavonoid contents of the extracts was determined using a modied method of Davis. Vitamin C was analyzed by HPLC method. According to the AEAC value, mate tea, green tea, black tea, oriental raisin tea, chamomile tea and burdock tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of total polyphenol compounds were observed in black tea, green tea and mate tea. The high concentrations of total flavonoid compounds were observed in mate tea, black tea and yam tea and the amount of vitamin C contents were found to be high in citron tea and green tea. As a result, steeping tea was much higher in antioxidant activity than either powdered tea or liquefied tea. According to the study, a high correlation was demonstrated between the total polyphenol contents and antioxidant activities in teas (r = 0.846) and correlations between the total flavonoid contents and antioxidant activities was statistically significant in teas (r = 0.625). It was found that also the proportional relationship established among the total polyphenol content and antioxidant activities. That is, antioxidant activity of teas has been confirmed to have been caused by the total polyphenol.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.37-42
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• 2002

Factors affecting the production of bacterial cellulose and organic acids in Kombucha fermentation were investigated. Kombucha was obtained by the fermentation (for 12 days at 3$0^{\circ}C$) of the green/black tea extract, supplemented with 10% white sugar, using an Oriental tea fungus as starter. Hitgher initial pH increased acid production with decreased cellulose production. With a cellulose pellicle or tea fungus broth as a starter, a 1~3 mm thick cellulose layer developed as a top layer every four days, and was removed subsequently while continuing fermentation. Addition of 30 mL tea fungus broth (13%, v/v) in Kombucha fermentation resulted in maximum production of a cellulose pellicle, indicating weak acid production. Yield of cellulose production at an early stage of fermentation was also higher when Kombucha was inoculated with a cellulose pellicle. In fact, addition of 1% (v/v) alcoholic beverage in the Kombucha fermentation activated the cellulose production, coupled with four times higher acid production.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.148-148
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• 2004