• Horticultural Science & Technology
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• v.30 no.5
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• pp.519-526
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• 2012

Anaerobic treated green teas were sealed with aluminum pack and stored for 12 months at three different temperatures such as 25, 4, or $-10^{\circ}C$. Anaerobic green teas were evaluated with respect to physiochemical properties and physiological functions. The longer anaerobic green teas were stored, their total nitrogen, tannins, or chlorophyll contents were reduced. Especially, the lower storage temperature of green tea resulted in less loss of physiochemical contents in green tea. Since green teas stored at $-10^{\circ}C$ exhibited less loss of physiochemical contents, compared to green teas stored at 25 or $4^{\circ}C$. The qualities of green teas stored at $-10^{\circ}C$ for 12 months were similar with those of teas stored at $4^{\circ}C$ for 8 months or stored at $25^{\circ}C$ for 4 months. Since 'a' value (green color) of green tea was considered as an important criteria to evaluate the tea quality. Anaerobic teas stored for 12 months were monitored their 'a' color values with -12.40 (fresh one), -10.54 ($-10^{\circ}C$), -9.77 ($4^{\circ}C$), and -9.06 ($25^{\circ}C$). Sensory evaluation results showed that anaerobic teas at $-10^{\circ}C$ were more favored than those at or 4 or $25^{\circ}C$. In conclusion, optimum storage temperature for anaerobic green teas should be $-10^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.448-456
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• 2008

In this study, domestic wheat white breads were prepared with the substitution of 1.5, 3.0, 4.5, and 6.0% Nelumbo nucifera G. tea powder(NNTP). The samples and a control were then compared with regard to quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, external and internal surface appearances, and sensory qualities in order to determine the optimal ratio of NNTP in the formulation. As the NNTP contents increased, the pH of dough and bread, baking loss, and lightness decreased, whereas the total titratable acidity of dough and bread increased. The fermentation power of dough expansion increased with increasing incubation time. The NNTP samples evidenced significantly higher specific volume, greenness, yellowness, resilience, and crumb consistency than were observed in the control group. However, hardness and fracturability evidenced the opposite effect. The water content and uniformity of the crumb pores were highest at a substitution level of 1.5%, and were lowest at a level of 4.5%. Crumb color, flavor, and delicious taste decreased with increasing NNTP contents, whereas lotus leaf flavor, astringency, bitterness, and off-flavor increased. Density of the crumb pore and crumb springiness were not significantly different among the samples. Softness, chewiness, and overall acceptability were maximal with the 1.5% substitution, and were minimal in the 6.0% group. In conclusion, our results demonstrate that $1.5{\sim}3.0%$ NNTP may prove quite useful as a substitute for domestic wheat flour in the production of white bread, and may evidence favorable nutritional and functional properties.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.398-405
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• 2010

In this study, white bread was prepared containing 1.5, 3.0, 4.5 or 6.0% barley leaves tea powder (BLTP). The samples along with a control were then compared regarding their quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, internal surface appearances and sensory qualities, all to determine the optimal ratio of BLTP. As the BLTP content increased, the pH of the dough and bread and the lightness decreased, whereas the total titratable acidity increased. The fermentation power of dough expansion increased with a longer incubation time. The control group was evidenced by a significantly higher specific volume and baking loss than that observed in the BLTP samples. However, greenness and yellowness evidenced the opposite effect. Hardness was highest at a substitution level of 1.5% and lowest at a level of 4.5%. Fracturability and resilience were not significantly different among the samples. For the internal surface appearance, darkness and greenness increased both increased at higher BLTP content. In the sensory evaluation, color, flavor and overall acceptability were highest in the control bread samples but minimal at a substitution level of 6.0%. Softness was the highest at the 3.0% substitution level and lowest in the control bread samples. Barley leaf flavor, astringency, bitterness and off-flavor increased as the BLTP content increased. Delicious taste was not significantly different among the samples. In conclusion, the results demonstrated that 4.5% BLTP may prove quite useful as a substitute for wheat flour in the production of white bread and may provide favorable nutritional and functional properties.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.267-272
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• 1981

The qualities of ginseng leaf teas prepared by six different processing methods were evaluated to develop the leaf tea. The leaf tea prepared by fermentation at $30^{\circ}C$ showed the highest in the ratio of 30 min water extracts to the total extractable matters. This ratio was followed in decreasing order by the heat dried tea and the one fermented at $25^{\circ}C$. The yellow, orange and red color intensities of water extracts were the highest in the tea prepared by toasting method followed by teas fermented at $30^{\circ}C\:and\:25^{\circ}C$. The amount of saponins extracted with boiling water was the highest in the tea fermented at $30^{\circ}C$ among teas investigated. This tea was also most acceptable in sensory evaluation by the flavour profile method.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.70-73
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• 1976

To develop a beverage indigenous to Korea, leaves of Doojoong tree (Eucommia ulmoides) were investigated for their chemical composition, extraction conditions and processing methods. It was concluded that Doojoong-tea from the leaves possesses sufficiently acceptable qualities as a favorite beverage.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.1-4
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• 2006

The biological qualities of green, black, and oolong teas were monitored by observing their microbial decontamination and insect disinfestation following gamma irradiation (0-10 kGy) and fumigation (MeBr or $PH_3$) during 6-month storage at room temperature. Plodia interpunctella Hubner was found as an important quarantine pest in teas used. In a comparative study, both treatments were found to be effective in disinfecting the stored samples. An irradiation dose of 5 kGy was sufficient to control all microorganisms related to the quality of teas, while fumigation with methyl bromide and phosphine showed no appreciable decontamination effect on the microorganisms. As a result, irradiation was found an effective alternative to fumigants for the improvement of biological tea qualities during storage.

• Journal of Nutrition and Health
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• v.12 no.1
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• pp.69-75
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• 1979

Stevia rebaudiana Bertoni M. can be cultivated in Korea as a new sweetness resource. It seems possible that stevioside the sweet substance extracted from the leaves of Stevia rebaudiana Bertoni M. can be used instead of saccharin. In order to obtain the fundamental data due to natural sweetening materials used of as additives to food stuffs such as coffee and tea etc. It was investigated to reduce the calories from coffee and tea without reducing the conventional sweetness, drinks sweetened with mixtures of stevioside and sucrose were prepared. The results obtained are as follows: 1) Mixture of 50% stevioside 40 mg (0.04%) (A) and 1.5% sucrose, 95% stevioside 20 mg (0.02%) (B) and 2.0% sucrose, and 50% stevioside 60 mg (0.06%) (A) and 95% stevioside 40 mg (0. 04%) (B), the sweetness of which in coffee corresponded to that of 7% sucrose in the drink, was prepared. 2) Mixture of 50% stevioside 60 mg (0.06%) (A) and 1.5, 2.0, 2.5% sucrose, 95% stevioside 40 mg (0.04%) (B) and 1.5, 2.0% sucrose, and 50% 80 mg (0.08%), 95% 60 mg (0.06%) (A,B), respectively the sweetness of which in tea corresponded to that of 7% sucrose in the above drink, was prepared. 3) Sucrose saving of 21.42-28.57% compared to equally sweet sucrose-sweetened coffee and tea could be achieved without deterioration of other taste qualities.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.407-412
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• 2011

Free and bound aroma compounds in green and fermented teas treated with microbial-fermentation were analyzed using headspace-solid phase microextraction gas chromatography (GC) and GC-mass spectrometry. Aldehydes and ketones in green tea decreased during microbial fermentation, whereas linalool and geraniol increased in the fermented tea. After enzyme treatment, (Z)-3-hexen-1-ol increased significantly following enzymatic hydrolysis of both green and fermented teas. In addition, benzaldehyde, 3-hexenyl acetate, and geraniol also increased in green tea with enzyme treatment. Bound aroma compounds in the green and fermented teas increased at different levels of added enzyme. We demonstrated the enhancement of both green and fermented teas by enzyme treatment, which can lead to improvement in the flavor qualities of green and fermented teas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.774-783
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• 2013

This study investigated the quality characteristics of boiled pork with different amounts (0.5, 1, 1.5, or 2%) of green tea, oolong tea and black tea extracts. Characteristics measured included approximate composition, water holding capacity (WHC), hardness, pH, Hunter's color value, total aerobic bacterial counts, volatile basic nitrogen (VBN), 2-thiobarbituric acid reactive substances (TBARS), and sensory qualities. Green tea approximately contained 3.4%, 31.8%, 5.5%, and 57.7% of moisture, crude protein, crude ash, and carbohydrate, respectively. There were no significant differences with the type of tea. However, the crude fat content of green tea, oolong tea, and black tea were 1.6%, 1.0%, and 0.9%, respectively. Green tea had the highest content of crude fat (p<0.05). Boiled pork approximately contained 55.1%, 38.6%, 5.2% and 0.9% moisture, crude protein, crude fat and crude ash, respectively. The WHC of boiled pork, with tea extract added, significantly increased and there were no significant differences according to the type of tea. The hardness of boiled pork significantly increased as the amount of tea extract added increased (p<0.05). The pH of the boiled pork was not significantly different after storage for one day, but significantly decreased in control groups and boiled pork with 0.5% of any tea extract added during storage. However, in boiled pork with 1%, 1.5%, or 2% of any tea extract added, pH was not significantly different during storage. The Hunter's L and b values decreased in all boiled pork. The Hunter's a-values also decreased in boiled pork with green and black tea extract added, but increased in boiled pork with oolong tea extract added. In boiled pork with tea extract added, total aerobic bacterial counts significantly decreased as the amount of tea extract added increased during storage (p<0.05). The VBN values significantly increased during storage in all groups. TBARS values were significantly lower in boiled pork with green tea extract added, oolong tea added (at concentrations of 1%, 1.5%, or 2%), and black tea extract added compared to control groups on the first day. The sensory evaluation results showed that the color, flavor, and overall acceptance of boiled pork containing 1% of oolong or black tea extracts had the highest scores but there were no significant differences. However, taste scores were significantly different (p<0.05). These results indicate that boiled pork has improved quality characteristics with 1% of oolong or black tea extracts added.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.199-202
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• 2004

Membrane technology is widely employed as a means of producing various qualities of water from surface water, well water, brackish water and seawater. This is also used in industrial wastewater treatment and its recycling process. A large volume of wastewater is generated by the steel industry. Presently, the treated wastewater from the steel industry cannot be recycled, because some of its components cause either direct or indirect problems.(omitted)