• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.227-231
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• 2004

Green, black and oolong teas were irradiated by $^{60}$ Co-gamma rays (0～10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650～1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively. The TL glow curves for minerals isolated from the non-irradiated teas were situated at about 30$0^{\circ}C$ with a low intensity, but for irradiated samples were approximately 15$0^{\circ}C$ with a high intensity. The TL ratios (TL$_1$/TL$_2$), calculated from values after initial radiation and then after re-irradiation of the teas, were below 0.1 for the non-irradiated samples and higher than 1.44 for all irradiated samples, enhanced the reliability of the identification results for TL. The signal intensity of PPSL and TL for irradiated teas decreased with the lapse of post-irradiation storage time at room temperature but was still distinguishable from that of the non-irradiated samples even after one year.

• 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 $-10^{\circ}C$.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.93-101
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• 2008

Research materials used were 55 kinds of flower teas proven in medicinal efficacy based on publications in oriental medicinal science. Efficacy in oriental medical science of the selected plants was classified into 11 groups, exterior-relieving herbs, removing dampness by promoting diuresis herbs, heatclearing herbs, purgative herbs, tonic herbs, qi-activating herbs, herbs as blood-tonics, herbs warming the intestine, qi-regulating herbs, herbs for removing dampness by means of aromatics, and herbs activating blood. Moreover, they were assorted by fever (hot, warm, slightly warm, common, cool, and cold), flavor (sweet, bitter, spicy, sour, and salty), and toxicity (toxic or nontoxic). Generally, flower teas have been known to be drinkable by all people. However, it is important to select proper flower teas considering physical constitution and health condition of the individual. One should be cautious in drinking flower teas containing toxic ingredients and weak people should be prohibited drinking them. Further clinical study on efficacy of flower teas will contribute to commercialization of these teas.

• Journal of the Korean Chemical Society
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• v.63 no.2
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• pp.78-84
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• 2019

High-resolution $^1H$ NMR spectroscopic technique has been widely used as one of the most powerful analytical tools in food chemistry as well as to define molecular structure. The $^1H$ NMR spectra-based metabolomics has focused on classification and chemometric analysis of complex mixtures. The principal component analysis (PCA), an unsupervised clustering method and used to reduce the dimensionality of multivariate data, facilitates direct peak quantitation and pattern recognition. Using a combination of these techniques, the various green teas and black teas brewed were investigated via metabolite profiling. These teas were characterized based on the leaf size and country of cultivation, respectively.

• Journal of Life Science
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• v.5 no.2
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• pp.20-20
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• Journal of Life Science
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• v.5 no.2
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• pp.76-80
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• 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.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.529-533
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• 2001

This study was carried out to characterize aroma of semi-fermented teas made traditionally in Korea temple. These teas had favorable floral aroma. The extraction of aroma compounds was accomplished by a simultaneous distillation and extraction method using a Likens and Nickerson's extraction apparatus. The concentrated extract was analyzed and identified by GC and GC-MSD. The main aroma components of these teas were 3-methylbutanal, 2-methylbutanal, (E)-2-hexenal, phenylacetaldehyde, 2-phenyl ethanol, geraniol, ${\beta}-ionone$ and nerolidol. Particularly, the concentration of phenylacetaldehyde was much higher concentration in semi-fermented teas than in green tea prepared from same place. The GC patterns of the aroma components in the semi-fermented teas were slightly different, though they were prepared in same place.

• Journal of the Korean Professional Engineers Association
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• v.19 no.4
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• pp.22-29
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• 1986

1) The recipe for tea is to mix tea leaves or tea buds with odorous pharmaceuctial materials, which are boiled and drunk, addition of honey only to that odorous pharmaceutical meterials without adding tea buds to that can be used. 2) Viewed from the part of tea plant the fruit of it accoupies most. The cereal does as much. 3) what we have referred to from the records on this subject are "Guogapylyong" which is of the yuan dynasty and "Jeungbo-Salymkeongje" which is of the Yi dynasty, based on which no trace of pure tea can be found but odorous pharmaceutical kinds of tea only were widely spread. 4) The characteristics of tea are to help make stomach strong, mind cleared, the lungs copious, counteract, and quench thirstiness. The tea help build liver as well as bring about health. 5) As a result of sense test, those kinds of tea were much better than contemporary kinds of teas as far as flovor and sweetness are concerned. Those teas had complex tastes, while teas of to day have simple one. 6) Because the history not so clear before the periods of Unified Sila that the recordings of teas are rare, we can hardly know about tea. Our ancestors really began to drink teas from the period of Unified Sila on. This country turning to the Koryo dynasty, tea drinking manner began to prevail so much that drinking tea became a ceremony. Daring the Yi dynasty it was much camplicated to make and boil the leaf tea. As a result of the previous fact pure tea came to have disappeared and odorous pharmaceutical became prevailent. 7) For value of exploiting Kungjuk tea (ginger tea seasoned with phyllostachy and addition of honeyl) was the highest among many. The worth of developing all the teas among all the beverages was regarded as that high of 51%, while even the tea regarded as worthless obtained 4％ of support, which is the lowest.

• 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.