• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.33-33
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• 2003

Most of leaf teas, except flower tea, were considered as good materials with basic conditions for tea manufacture because water content was below 6 %, Crude protein was the greatest component in roasted young leaf tea, crude fats in roasted mature leaf tea and ashes in fermented young leaf tea. Caffein were present as the highest amount(5.18%) in steamed mature leaf tea, showing less amount than greenp teas. Catechin were contained as the highest amount in all kinds of teas, especially fermented young leaf tea. was the highest(9.57%). Tannin, which highly related with tea quality including astringent taste, color and perfume, were present as the highest amount in fermented young leaf tea.(중략)

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.156-163
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• 2014

In order to develop tea by using the leaves of stevia, which is a herbal plant, and to solve the disadvantages of stevia dried leaf tea, we have manufactured the steamed tea, stir-fried tea and fermented tea by changing the manufacturing processes. As a result of the sensory tests, the steamed tea, stir-fried tea and fermented tea received higher evaluations than the dried leaf tea. In terms of efficiency, it is desired that the total number of steaming and stir-frying is only once, but the fermentation is found to be the most desirable for 2 days. There are no trends for changes in the general ingredients, mineral and free amino acid contents of stevia leaf teas by different manufacturing processes. As a result for the measurement of antioxidant activities, the steamed tea and dried leaf tea did not show significant differences, but the stir-fried tea and the fermented tea show significantly low antioxidant activities as compared to the steamed tea. The contents of stevioside in both the stir-fried tea and the fermented tea were less than that in the dried leaf tea, but in the steamed tea, there was no significant difference in the content of stevioside. Base on the present observations, this study supports high potentials of steaming process in order to produce new stevia leaf tea.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.165-172
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• 2007

This study was conducted to investigate the antioxidant amounts and properties of barley leaf tea and green tea at under various leaching conditions. The leaching temperatures and times of the distilled water were 50, 70 and $90^{\circ}$C for 1, 3 and 5 min, respectively. The levels of crude fat and ash in the barley leaf tea were higher than those in green tea. Brown color intensity and flavonoid absorbance increased with leaching temperature. The highest vitamin C levels and water-soluble phenol resulted at $90^{\circ}$C for 3 min. The DPPH radical scavenging activities of the barley leaf tea and of green tea were 11.06 and 50.56%, respectively, compared to 2.9% for L-ascorbic acid (150 ppm). The nitrite scavenging activities of barley leaf tea and green tea were 95.11 and 74.88%, respectively. The SOD-like activities of barley leaf tea, green tea, and L-ascorbic acid (150 ppm) were 12.99, 8.33, and 12.75%, respectively. The antioxidant effect of green tea was higher than that of barley leaf tea and lastly, the SOD-like activity of barley leaf tea was as high as that of green tea.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.1-6
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• 1992

Chemical composition was determined to evaluate the quality of Panel ginseng-leaf tea over green teas. Ginseng-leaf tea was shown to contain higher contents of soluble matter, ascorbic acid and lower contents of tannins, as compared to tea leaves. The profiles of ginsenoside and sugar of ginseng-leaf tea were noticeably different from those of ginseng roots and the sample maintained high levels of these components under the manufacturing process. Total unsaturated fatty acids and free amino acids were estimated to be decreased in ginseng-leaf tea as compared to those of ginseng leaves. The compositions of amino acids and minerals in ginseng-leaf tea were similar to those of tea leaves and glutamic acid, aspartic acid, leucine, calcium, potassium, sodium, and copper were found to be major components.

• 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.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.181-188
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• 1996

Chemical compositions were investigated by harvested months and produced methods. The level of crude protein and crude ash of ginseng leaf tea harvested in July was slightly higher than it harvested in September. However, the level of crude fat and carbohydrate of ginseng leaf tea harvested in September were higher than it harvested in July. The results indicated that the harvest month influenced the chemical composition of the ginseng leaf tea. Also, the level of free sugar was increased when the ginseng leaf team harvested in September was produced by FHT(fermented and then hot-air dried) or HHT(heated and then hot-air dried). The results indicated that the subjects were preferred the color of ginseng leaf tea which was harvested in July. However, they were preferred the aroma and ginseng's aroma which was harvested and produced by HHT in September. Because they responded that the ginseng leaf tea tasted too bitter, it suggested that the taste of bitterness needed to remove. Also, the astringent, the savory, after aroma, and after say cry of the ginseng leaf tea was improved with FHT or HHT, and those results obtained from September's harvest rather than July's. Therefore, the overall quality of ginseng leaf tea which was harvested in September and produced with FHT or HHT were evaluated better than it of DHT(dried on the shade and then hot-air dried).

• Journal of the East Asian Society of Dietary Life
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• v.21 no.3
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• pp.367-374
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• 2011

The purpose of this study was to determine the optimum condition for producing tea leaf Jeung-pyun that does not contain added parched tea leafs (0, 0.5, 1, 1.5, and 2%) while producing Jeung-pyun that has a variety of functional ingredients and to investigate the possibility of making practical application of tea leafs. Moisture contents were 56 ~66% and there were no significant differences among the samples. The pH of Jeung-pyun samples was 5.65~5.74. The L-value decreased as the amount of added tea leaf increased, and the a-value was low in the group made with added tea leafs. The b-value was high in the 1% added group and had a tendency to increase vs the control group as amount of added tea leaf increased. In the groups with added tea leaf the volume was evaluated as being higher in the order of 1>1.5>2%. The specific volume of the group with added tea leaf was evaluated as being higher in the order of 1>1.5>2%. Sensory characteristics of the group with added tea leaf were evaluated as being high. For characteristics of cell uniformity, rice wine flavor, and sweetness, the control group was evaluated as being high, and for characteristics of color, moistness, and softness the 1% added group was evaluated as high. Astringency was evaluated as being high in the 2% added group. Texture profile analysis was conducted after samples were maintained in an incubator at $20^{\circ}C$ for 0, 1, 3, 5, and 7 days. Characteristics for hardness, gumminess, chewiness tended to increase with longer periods of storage. Characteristics for cohesiveness, springiness tended to decrease as the storage period increased. As determined by this study, addition of 1% tea leaf was the most favorable method for making use of tea leafs the production of Jeung-pyun and a potentiality for the use of tea leafs in food was discorvered.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.1
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• pp.62-70
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• 2000

This study was conducted to investigated the kimchi quality of the addition of green tea extract and green tea leaf. Kimchi was examined for pH, titratable acidity, the changes in the number of microorganism, color,sensory evaluation . The pH and titratable acidity of kimchi at the addition of 5%, 1% of green tea extract and green tea leaf were higher and lower than those of control kimchi. the number of total microoranism at 21 days. were detected much more in the kimchi added green tea extract and green tea leaf than in control. The number of coliforms up to 7 days of fermentation were detected. And those at 14-21 days were not detected but those of 28 days were detected. The number of coliforms at 28 days were most lowest in the kimchi added green tea extract 3%. The number of lactic acid bacteria were detected more in the kimchi added green tea leaf. As a result of sensory evaluation during fermentation, the kimchi added green tea extract 5% was the highest score in carbonated taste. texture and overall quality. As the result of correlation between sensory characteristics and mechanical characteristics, it was found that sensory characteristics of sour taste is negatively related to the mechanical characteristics of L value, while it is positively related to the texture. The a values is negatively related to the sensory characteristics of overall quality. The b values is positively related to the sensory characteristics of sour taste.

• Journal of the Korean Society of Food Culture
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• v.18 no.3
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• pp.226-234
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• 2003

The effects of dried green tea leaf powders on serum lipid concentrations were evaluated in rats. Sixty male Sprague-Dawley rats weighing $100{\pm}10g$ were divided into six groups and fed high fat diets for six weeks. Experimental groups were administered with following diets; Normal fat diet and normal and high fat diets with 1% dried green tealeaf powders. Tissue weights of liver, lung, stomach, heart, kidney and spleen of high fat diet exposed rats were reduced by dried green tea leaf powders groups. The concentrations of serum triglyceride in rats fed the dried green tea leaf powders were lower than those in other groups. The concentrations of total cholesterol in green tea leaf powders the were lower than those in high fat diet groups. The concentrations of HDL-cholesterol in serum of the dried leaf powders green tea were significantly higher than those of other groups. The levels of LDL-cholesterol in serum of the dried green tea leaf powders groups were tended to be lower than those of other groups. GPT and GOT were decreased in dried green tea leaf powders groups and than in the high fat group. LDHase was lower in the dried green tea leaf powders groups than in the high fat group. These results suggest that dried leaf powders green tea groups may reduce elevated levels of serum lipid concentrations in rats fed high fat diets.

• 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.