• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.28-35
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• 2011

The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

• Journal of the Korean Home Economics Association
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• v.44 no.9
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• pp.21-29
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• 2006

The purpose of this study was to investigate the preferences and utilization of green tea and its products for adults living in Chonbuk area. Self-administered questionnaires were collected from 388 (117 male, 271 female) subjects. who were classified into 5 groups by age. Data were analysed by chi-square and ANOVA. The results can be summarized as follows. On the investigation of preferences, there was a significant difference between and among the age groups(p<.001). More than 20% of the subjects in the $20{\sim}29$ years group preferred coffee and juice. A half of the elderly over 60 years preferred a kind of green tea. The frequency of green tea drinking was not significantly influenced by age. Drinking green tea less than once a day was replied by 59.0% of the subject of whom 44.3% drank the green tea at home. and 42.0% got information about green tea from TV or radio. Regarding the satisfaction with products using green tea, 62.6% of the subjects responded only 'mediocre.' The brown rice-green tea was marked to be the highest in terms of recognition among all kinds of products. The green tea-related products were rated higher by the elder group. In conclusion, future research should focus on the development of green tea and its products in accordance with the consumption pattern in each age group.

• 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.

• Korean Journal of Clinical Pharmacy
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• v.28 no.4
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• pp.342-346
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• 2018

Background: Green tea extracts are approved as nonprescription drug and available as health functional foods, health foods, and beverages. Clinical information on the products is lacking. Methods: Information about the products on green tea nonprescription drugs was obtained from the website of the Korea Pharmaceutical Information Center. The Naver, i.e., a top ranking online search portal, was used for compiling the list of the health functional food products using key words of 'green tea catechin' on August 23, 2018. The recommended daily dosages of catechins were calculated as 30% of the total dried mass of green tea and about 50% of the catechins were considered as epigallocatechin gallate (EGCG). Results: A total of two types of nonprescription drugs containing green tea powder or extracts, nine health functional food products, and three types of health foods were found. The regulatory requirements of the EGCG exceeding 800 mg were reported to be associated with adverse effects of elevated liver enzyme. If consumers take several green tea products concurrently, such as nonprescription drugs with health functional foods or health foods, it could exceed the recommended amount of EGCG. Conclusion: The concurrent use of green tea products as nonprescription drugs, health functional foods, and healthy foods may lead to an increased exposure to EGCG. Pharmacists should be aware the availability of various types of green tea products and the potential risk of liver toxicity due to excessive consumption of EGCG.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.295-299
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• 2004

The prices of domestic green tea products are relatively expensive and price differences within products of the same levels of quality are various. Also, there is no basic criteria on evaluation of green tea quality. To group 43 commercial green tea products into several parts by the principal component and cluster analyses, this work was done by use of 8 chemical constituents which were analyzed by NIR system. The principal component and cluster analyses revealed 8 groups. The first group included 16 products that had lower free amino acid and theanine contents. The second group included 5 products having higher free amino acid and theanine contents, but lower ash contents. The third group included 13 products showing medium values of 8 constituents. The IV group included 4 products having higher contents of moisture, free amino acids, and theanine. The V group included 1 product showing higher moisture but lower catechins contents. The VI group included 2 products that had higher moisture and catechins contents, but lower free amino acid and theanine contents. The VII group had higher moisture and catechins contents. The VIII group had higher ash and vitamin C contents. The free amino acid contents which were the most important in flavor evaluation of green tea quality did highly positively correlate with the contents of total nitrogen $(0.956^{**}),\;theanine\;(0.981^{**}),\;and\;caffeine\;(0.793^{**})$, but negatively with the contents of ash $(-0.884^{**})$. The catechins used as for functional ingredients did correlate with contents of caffeine(+) and vitamin C(-), respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1571-1576
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• 2014

Nutritive values of green and black tea by-products and anti-nutritive activity of their tannins were evaluated in an in vitro rumen fermentation using various molecular weights of polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP) and polyvinyl polypyrrolidone as tannin-binding agents. Significant improvement in gas production by addition of PEG4000, 6000 and 20000 and PVP was observed only from black tea by-product, but not from green tea by-product. All tannin binding agents increased $NH_3$-N concentration from both green and black tea by-products in the fermentation medium, and the PEG6000 and 20000 showed relatively higher improvement in the $NH_3$-N concentration. The PEG6000 and 20000 also improved in vitro organic matter digestibility and metabolizable energy contents of both tea by-products. It was concluded that high molecular PEG would be suitable to assess the suppressive activity of tannins in tea by-products by in vitro fermentation. Higher responses to gas production and $NH_3$-N concentration from black tea by-product than green tea by-product due to PEG indicate that tannins in black tea by-product could suppress rumen fermentation more strongly than that in green tea by-product.

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.183-189
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• 2003

This study was carried out to evaluate effect of dietary green tea by-products (GTB) on laying performance and quality of eggs in hens. A total of 96 laying hens (22-week-old) "Tetran Brown" were allotted to four dietary treatments, which containing 0, 2, 4 and 6% green tea-by products. The results showed that the egg production increased (P＜0.05) in layers fed diets containing 4% or 6% green tea-by products compared to the layers fed control no GTB. Egg weight and egg mass in layers fed diets containing 2% green tea by-products significantly decreased compared to those in the other groups (P<0.05). The feed intake was lower in layers fed diets containing 2% and 6% green tea by-products. The feed conversion ratio was lower (P<0.05) in layers fed diets containing 4% or 6% green tea by-product supplementation respectively. The egg shell thickness was no significantly different between layers fed the control and green tea by-product diets (P>0.05). The egg yolk cholesterol tended to decrease when layers fed diets containing green tea by-products, although the differences were not significant (P＞0.05). The linolenic and docosahexaenoic (DHA) acid contents in egg yolk significantly increased in layers fed diets containing different levels green tea by-products compared to those fed control diet (P<0.05). These results suggest that inclusion of green tea by-products in layer diets is suitable for hens without negative effects on egg composition.

• Journal of Ginseng Research
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• v.6 no.1
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• pp.30-37
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• 1982

This study was conducted to investigate the water vapor permeability of packaging film, Al- foil laminated paper, and sorption properties of dehydrated and powdered foods. The results are as fellows. 1. Absorption rate of each products was greately affeoted by physicochemical properties of foods rather than initial moisture contents of the products. 2. The absorption rate of each products were in the order of freeze dried coffee, spray dried coffee, freeze drie4 ginseng extract, spray dried ginseng extract, ginger tea, black tea, citrus juice Powder and ssang wha tea. 3. Most of the products such as freeze dried coffee, spray dried coffee, freeze dried ginseng extract, ginger tea and black tea have shorter than a month of shelf life. 4. The stability of the products were greatly affected by its desorption properties than the degree of desorption of moisture. 5. Water vapor permeability of packaging materials which are laminated Al-foil with polythylene and glassin paper were mainly affected of thickness of Al-foil and polyethylene.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1999.05a
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• pp.62-62
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• 1999

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.827-830
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• 1997

Sensory evaluation method was used to develop a type jujube tea the organoleptic properties were evaluated with regard to the optimum sugar content, clarity, drinking temperature and fruit pulp content of the jujube tea. Clarified jujube tea extracted from 25% by weight of dry jujube fruits and 75% water was preferred to those from 15%, 20% and 30% jujube fruites although those from 20% and 30% were not significantly different at 5%level. In spite of the average acceptability score of cloudy jujube tea with 5% of added fruit pulp was not significantly different from that of clarified one, the more fruit pulp in the tea products the worse its acceptability. Cold jujube tea was preferred to warm and hot ones, but these were not significantly different.