• Korean journal of food and cookery science
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• v.25 no.2
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• pp.150-159
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• 2009

The purpose of this research was to improve the quality of Sulgidduk by additions of green tea or rosemary powder to enhance its functional properties and antimicrobial effects. The green tea or rosemary powders were added to the Sulgidduk at different levels (1 or 3%), and color values, textural characteristics, sensory qualities, pH values, and acetic acid values were evaluated. With higher amounts of green tea or rosemary powder, the L-values of samples decreased and a-and b-values increased. Texture profile analyses indicated that hardness was significantly different among all the samples. The sensory evaluation results showed that the 1% addition of green tea or rosemary powder did not cause significant differences in overall acceptability, flavor, or taste. During storage, pH values decreased in all groups and the control group showed the lowest value. Acetic acid values increased during storage and the control group showed the highest value in the last stage of storage. Finally, the L- and a-values of samples did not change significantly during storage.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.266-271
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• 2004

In this study, rice was cooked with 0%, 0.5%, 1.0% and 2.0% green tea powder content to improve functionality of cooked rice. The effects of green tea powder content on the physical, texture and sensory characteristics of cooked rice were examined. Moisture contents of cooked rice with green tea powder were decreased with increasing amounts of added green tea powder. Initial pasting temperature of rice powder was showed an increase with increasing amounts of added green tea powder, besides peak viscosity was decreased. The solubility and swelling power were decreased with increasing amounts of added green tea powder. The color of cooked rice was darkened gradually with the increasing amounts of added green tea powder, and showed the dark green. Sensory adhesiveness was gradually decreased with the increasing amounts of added green tea powder, and cohesiveness, gummness, chewiness and hardness were increased. Sensory glassiness, overcook, stickiness and hardness had lower score than control group, but sensory color, flavor and overall acceptability had higher score with addition of 1.0% and 2.0% green tea powder. Concludingly, in items of overall sensory, cooked rice with 1.0% green tea powder showed the best result.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.876-881
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• 2008

The aim of this study was to evaluate the quality characteristics and antioxidant activities of green tea garlic paste added calcium. Garlic was heated with green tea and charcoal at high temperature ($120^{\circ}C$) and high pressure ($1.5\;kgf/cm^2$) for 20 min, and then added several calcium sources (calcium carbonate, calcium citrate, calcium lactate, mixed calcium, calcium powder). Calcium carbonate, mixed calcium or calcium powder significantly increased pH of green tea garlic paste (p<0.05). All kinds of calcium sources significantly increased the viscosity of green tea garlic paste (p<0.05). Solid soluble content of green tea garlic paste was increased only in calcium citrate and calcium powder groups. Lightness, redness and yellowness of green tea garlic paste with calcium were increased, compared with control group (green tea garlic paste without calcium). The antioxidant activities by DPPH and hydroxyl radical scavenging activity of green tea garlic paste added calcium citrate, calcium lactate or calcium carbonate group were much higher than those of the other control groups. The garlic odor and garlic taste by sensory test were significantly weaker in calcium carbonate or calcium citrate group (p<0.05). Based on these results, it was suggested that calcium carbonate or calcium citrate is appropriate material for deodorizing and fortifying agent for green tea garlic paste.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.3
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• pp.415-422
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• 2010

This study was performed to investigate the quality characteristics of yanggeng added with Green Tea Powder. The yanggeng was prepared with Green Tea Powder, Agar, Sugar and Salt. The yanggeng is made with various levels (0, 2, 4, 6, 8%) of gree tea powder added. Hunter's color value, texture profile analysis, and sensory characteristics of gree tea powder Yanggeng were examined. The addition of gree tea powder has tendency to increase the water content of yanggeng. As the content of gree tea powder increased, the lightness (L) and redness (a) decreased. In texture profile analysis, hardness decreased with increasing gree tea powder content. Cohesiveness and springiness didn't showed significant differences according to amount of gree tea powder. The results of the sensory evaluation showed that the sweetness, softness and overall acceptability were the highest scores at yanggeng containing 4% level of gree tea powder. In conclusion, the result shows that the yanggeng with 4% of gree tea powder is the best.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.421-424
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• 2008

Edible red algae paper coated with green tea ext Tact was prepared and determined the microbial growth and quality change of kimbab wrapped with the paper during storage. The paper coated with green tea extract had the antimicrobial activity against Listeria monocytogenes and Escherichia coli. After 12 hr of storage of kimbab, packaging with the paper coated with green tea extract decreased populations of total aerobic bacteria by 1 log cycle. Kimbab wrapped with the red algae paper coated with green tea extract had 5.5 mg malondialdehyde (MDA)/kg after 12 hr, in contrast to the control of 7.4 mg MDA/kg. Kimbab with red algae paper with green tea extract was better than the control in terms of sensory qualities. These results clearly indicate that kimbab can be packaged with red algae paper coated with green tea extract, resulting in extending its shelf life.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.815-823
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• 2014

Green tea has been known to show beneficial effects on alleviating stress. The present study was conducted to determine the effects of dietary green tea on quality of eggs, during storage, laid by laying hens treated with corticosterone in order to mimic the current practice of the egg market. Hens were fed for 2 weeks one of three diets containing green tea at 0.0, 0.4 or 1.0%. Each dietary group was divided into two subgroups receiving corticosterone at 0 or 30 mg/kg for 1 week. Eggs, laid at 5-7 days following the initiation of corticosterone treatment, were stored at $10^{\circ}C$ for 1 or 5 weeks and then analyzed for egg quality. After 1 week of storage, egg weight was significantly increased by green tea (p<0.025) but decreased by corticosterone (p<0.0001), but no interaction was observed between both. Corticosterone decreased shell color (p<0.0001) but green tea significantly decreased shell strength (p<0.006). Yolk color, albumen height and Haugh unit were not affected by both treatments. After 5 weeks of storage, corticosterone resulted in reduced egg weight (p<0.01) and eggshell color (p<0.001) and increased shell strength, which were not attenuated by green tea. Taken together, the results of the current study show that dietary corticosterone reduces egg quality during storage, which are attenuated in part by dietary green tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1021-1025
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• 2003

The study was to investigate the quality of wet noodle added with the powder green tea. The wet noodles were prepared to the ratio of 1, 2, 3, 5, 7.5 and 10% (w/w) of the powder green tea based on a flour weight. The initial pasting temperature in an amylograph was increased as the increase of the powder green tea, while peak and final viscosity as the increase decreased. The weight and volume of cooked noodles were decreased, and turbidity of soup was increased with the addition of the powder green tea. L and a values of wet noodles were decreased with the addition of the powder green tea, and b value was increased. Texture profile analysis of cooked noodle showed a increase of hardness, cohesiveness, springiness, chewiness up to 2% powder green tea, but decreased from 3% power green tea. However, adhesiveness decreased as the increase of the powder green tea. From the sensory evaluation, the wet noodles included 1% powder green tea were similarly evaluated as the noodle used whole wheat flour.

• 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.

• Korean journal of food and cookery science
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• v.15 no.2
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• pp.95-101
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• 1999

This study was carried out to prepare green teas by traditional roasting manufacturing process, Ku Geung Ku Po and to determine the quality charateristics of the green teas by examining the change of their main components induced during this roasting process. The content of total sugars in unroasted tea leaves was 7.82%. Its content of roasted teas was decreased by increasing the number of roasting and there was significantly differences between samples. The content of total sugars in 9th roasted green tea was 3.98%. The total nitrogen contents of green teas produced by this process were 4.96∼6.38%. The more the number of roasting and the less content of tannin in green teas. And the ratio of total nitrogen and tannin in tea leaves 21.97 but its ratio in 9th roasted tea was increased to 45.54. The ascorbic acid in tea leaves consisted in 1,820.3 mg/100g but its content was decreased by increasing the number of roasting process. Whereas the content of caffeine in green teas was not reduced significantly by this traditional method. Of all amino acids, green tea produced by Ku Jeung Ku Po was rich glutamic acid, lysine and aspartic acid. And especially, phenylalanine, which was rarely found in other green teas, was abundant in these green teas. The compositions of glutamic acid and methionine were increased as increasing the number of roasting process but those of aspartic acid and arginine decreased by these processing. The main fatty acids of Ku Jeung Ku Po green tea were linolenic acid, linoleic acid and palmitic acid and the contents of unsaturated fatty acid in green teas were composed over 70% of total fatty acid. And the fatty acid contents in green teas were not affected during Ku Jeung Ku Po's process. The contents of minerals in these teas was rich in the oder of potassuim. magnessuim and calciumim, and these contents were not observed the prominant change during the process.