• Korean journal of food and cookery science
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• v.26 no.4
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• pp.422-427
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• 2010

This study was conducted to investigate the antioxidant effect and properties of unfermented tea and fermented tea made with Rhodotorula yeast. The levels of crude fat and crude protein in the fermented tea were higher than those in the unfermented tea. The water-soluble phenol levels of unfermented tea and fermented tea were 912.5 and 2,445.24 ppm, respectively. The total amino acid content of fermented tea was greater than that of unfermented tea;,- the amino acid concentrations of alanine, valine, leucine, and lysine were 25.58, 24.38, 27.96, and 14.14 ${\mu}g/mL$, respectively. The DPPH radical scavenging activities of the unfermented and fermented teas were 32.14 and 41.57%, respectively; this is in contrast to 29.73% for L-ascorbic acid(150 ppm). The reducing power activity of fermented tea was 41.57%, and that of unfermented tea was 32.14%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.869-874
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• 2005

The purpose of this study was to determine the qualities of loaf breads added with green tea powder, minimum fermented tea powder (fermented for 10 hrs), medium fermented tea powder (fermented for 17 hrs), and black tea powder (fermented for 24 hrs). The moisture content of loaf bread added with green tea and three types of fermented tea was $36.02\~36.44\%$ and was similar to the control group of $36.98\%$. The content of crude protein and ash of loaf bread added with green tea powder and fermented tea was higher than that of control group. The water holding capacity of loaf bread added with green tea powder was the highest and was followed by the fermented tea added group and the control group. The volume and specific volume of loaf bread were high in tile order of the control group, the fermented tea added group, the green tea added group. The lightness of loaf bread got lower, while the redness and the yellowness of the bread 9ot higher as loaf bread was added with more fermented tea. The hardness of loaf bread get higher, but the cohesiveness got lower as loaf bread was added with the more fermented tea. The gumminess and chewiness of loaf bread added with black tea powder were the highest. The result of sensory evaluation of the loaf bread showed that the preference of the color was tBle highest in the control group, while the preference of the flavor and the taste was the highest in the green tea group and the minimum fermented tea group. The preference of overall acceptability of loaf bread was the highest in the minimum fermented tea group.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.148-157
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• 2005

This study was investigated to determine antimicrobial activity of the water and ethanol extracts of Korean wild green tea, semi-fermented tea, and fermented tea. Antimicrobial activity was examined against 8 kinds of several microorganisms. The minimum inhibitory concentration (MIC) of the water and ethanol extracts of green tea showed the most active antimicrobial activity against B. subtilis 0.2 mg/mL in Gram positive bacteria and P. fluorescens 0.3∼0.5 mg/mL in Gram negative bacteria. But the extracts did not show antimicrobial activity against lactic acid bacteria and yeast at the level of less than 1 mg/mL. Antimicrobial activity got lower as tea got more fermented. Antimicrobial activity of ethanol extracts from green tea, semifermented tea, and fermented tea was stronger than that of water extracts. Antimicrobial activity of the water and ethanol extracts of green tea, semi-fermented tea, and fermented tea was not destroyed at 50∼121$^{\circ}C$, and pH 3∼11, which proved to be very stable when given over heat, acid & alkali treatment. The ethanol extract of green tea, semi-fermented tea, and fermented tea was fractionated in the order of hexane, diethyl ether, ethyl acetate and water fraction. The highest antimicrobial activity was found in the water fraction, but not found in hexane fraction, while antimicrobial activity of fermented tea was not found in ether fraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.356-362
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• 2003

The present study was conducted to know the physicochemical properties of non fermented tea and fermented teas with the fermented time of 0 hr (non fermented tea), 10 hrs, 17 hrs (semi-fermented tea), 24 hrs (black tea), respectively The moisture content of non fermented tea, semi fermented, and black tea was 3.01% ~ 3.29%. The contents of reducing sugar, crude lipid, crude protein were increased and that of ascorbic acid was decresed with fermentation. The total contents of those increased as tea was more fermented. The contents of the citric acid and the malic acid were increased with fermentation, but the content of the succinic acid was decreased. However, the total content of organic acid was generally increased with fermentation. The total content of the amino acid was increased with fermentation. In non fermented tea, Thr+theanine, the Asp, and the Glu, were determined in order of content. In semi-fermented tea and black tea, Ter+theanine, Glu, and Asp were determined in order of content. The rate of essential amino acid in the total content of free amino acid was increased with fermentation. The content of theanine was 1.21% in non fermented tea and 1.50% in black tea. The contents of theanine were increased as tea was more fermented. The content of caffein was 3.57% in non fermented tea and 3.55 ~ 3.60% in semi-fermented tea and black tea. These results were inconsistent in the content of caffein. Five kinds of catechin, that is, cathechin, epigallocathechin, epicathechin, epigallocathechin gallate, and epicathechin gallate were extracted. The content of catechin was 14.18% in non fermented tea, but decreased sharply as tea was more fermented.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.308-314
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• 2009

In this study, we examined the composition of catechins, theaflavins and alkaloids in leaves during processing to fermented black tea, which is produced by withering, roll breaking, and fermentation of Korean Yabukida tea plant. In addition, we determined the optimal conditions for the production of fermented black tea. The average moisture content in fresh leaves was 70.85%, which dropped to 3.07% in fermented black tea at the last stage of production. When the leaves were analyzed by HPLC, seven types of catechins, four types of theaflavins and three types of alkaloids were identified. The levels of catechins, theaflavins, and alkaloids were then evaluated after being processed into fermented tea. From these experiments, we found that the level of theaflavins, which determines the property of the tea, increased during fermentation. This effect resulted from the change in EGCG, ECG, EGC, EC during the process of fermentation. We also found that the maximal amount of theaflavins was created after 1-2 hours of fermentation. Thus, our results imply that the best condition for producing fermented black tea would be to ferment for 1-2 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1073-1078
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• 2011

Changes of antioxidative components and activity of fermented tea manufactured by Bacillus subtilis, Saccharomyces cerevisiae, and Lactobacillus bulgaricus were evaluated during the fermentation period. The ascorbic acid content in the fermented tea was relatively lower (43.62~62.84 mg%) than that of green tea (66.74 mg%) during the entire fermentation period. The tea fermented by L. bulgaricus, which had the least contact with air, showed less change in ascorbic acid content. The polyphenol content of green tea was 14.88%, whereas that of fermented tea was 11.54~14.12% and it decreased during the fermentation period. The amount of flavonoids in green tea was 7.78 mg%, whereas that of fermented tea was 4.33~7.88 mg%. DPPH radical scavenging activity and ABTS reducing activity of green tea were 87.47% and 203.22 AEAC mg% (ascorbic acid equivalent antioxidant capacity), respectively, whereas those of fermented tea were lower than green tea. Results indicated that the antioxidative components and activity of fermented tea were lower than those of green tea during the fermentation period. But, when the sensory and hygienic quality are considered, fermented tea can be one of the higher quality tea products on the market.

• Textile Coloration and Finishing
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• v.26 no.4
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• pp.353-362
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• 2014

This study attempted to determine the effects of fermented green tea extracts on hair by using them in a perm. For this, hair is bleached, and then the fermented green tea extracts and water were supplied to the hair using a mist sprayer. Then the hair was permed, and hair damage was tested. Regarding hair moisture levels and wave formation, specifically, the morphological changes of hair were investigated with the Scanning Electron Microscope(SEM). The study results found the following. In terms of wave formation, the fermented green tea extract-based perm was much better than the general perm. In addition, hair bleaching was more serious in the latter. According to analysis on hair moisture using SEM, hair damage was more prevalent in the general perm as well. Therefore, it was confirmed that green tea extract-based perms cause less damage to the cuticle. In other words, the potential of fermented green tea extracts as a hair cosmetics material was discovered. Furthermore, it appears that the study results contribute to the development of low-irritating scalp and hair care products using the anti-inflammatory and antimicrobial properties of the fermented green tea extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1807-1813
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• 2010

To manufacture the fermented tea with hygienic quality, green tea was fermented using Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus bulgaricus and chemical composition and sensory changes were evaluated during fermentation period. The lightness of the fermented samples decreased; in contrast, redness and yellowness increased. Especially, the color change of the fermented tea using B. subtilis was higher than those of control and other samples with different microorganisms during fermentation period. Chlorophyll contents were decreased by similar level regardless of fermentation treatments. The fastest decrease of total catechins contents were found in the tea fermented with B. subtilis and significantly reduced by increase of fermentation period. However, total catechin contents of the tea fermented by L. bulgaricus were not decreased. The caffeine contents of the microbial fermented teas were more decreased than that of control, even though the decrease was slight. Sensory panelists preferred the tea fermented by B. subtilis to those of control or other fermentation treatment.

• 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