scholarly journals (S)-Linalyl, 2-Phenylethyl, and Benzyl Disaccharide Glycosides Isolated as Aroma Precursors from Oolong Tea Leaves

1994 ◽  
Vol 58 (8) ◽  
pp. 1532-1534 ◽  
Author(s):  
Wenfei Guo ◽  
Ryuji Hosoi ◽  
Kanzo Sakata ◽  
Naoharu Watanabe ◽  
Akihito Yagi ◽  
...  
Keyword(s):  
Tea Leaves ◽  
Oolong Tea ◽  
Aroma Precursors

cis- andtrans-Linalool 3,7-Oxides and Methyl Salicylate Glycosides and (Z)-3-Hexenylβ-D-Glucopyranoside as Aroma Precursors from Tea Leaves for Oolong Tea

1996 ◽  
Vol 60 (11) ◽  
pp. 1815-1819 ◽  
Author(s):  
Jae-Hak Moon ◽  
Naoharu Watanabe ◽  
Yasuyuki Ijima ◽  
Akihito Yagi ◽  
Kanzo Sakata
Keyword(s):  
Methyl Salicylate ◽  
Tea Leaves ◽  
Oolong Tea ◽  
Aroma Precursors

scholarly journals Utilization of a Gas-Sensing System to Discriminate Smell and to Monitor Fermentation during the Manufacture of Oolong Tea Leaves

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ting-Shiang Tseng ◽  
Mei-Hui Hsiao ◽  
Po-An Chen ◽  
Shu-Yen Lin ◽  
Shih-Wen Chiu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Critical Factor ◽  
Current Method ◽  
Sensory Function ◽  
Oxide Semiconductor ◽  
Tea Leaves ◽  
Linear Discriminant ◽  
Oolong Tea ◽  
Olfactory Sense ◽  
On Line

The operational duration of shaking tea leaves is a critical factor in the manufacture of oolong tea; this duration influences the formation of its flavor and fragrance. The current method to control the duration of fermentation relies on the olfactory sense of tea masters; they monitor the entire process through their olfactory sense, and their experience decides the duration of shaking and setting. Because of this human factor and olfactory fatigue, it is difficult to define an optimum duration of shaking and setting; an inappropriate duration of shaking and setting deteriorates the quality of the tea. In this study, we used metal-oxide-semiconductor gas sensors to establish an electronic nose (E-nose) system and tested its feasibility. This research was divided into two experiments: distinguishing samples at various stages and an on-line experiment. The samples of tea leaves at various stages exhibited large differences in the level of grassy smell. From the experience of practitioners and from previous research, the samples could be categorized into three groups: before the first shaking (BS1), before the shaking group, and after the shaking group. We input the experimental results into a linear discriminant analysis to decrease the dimensions and to classify the samples into various groups. The results show that the smell can also be categorized into three groups. After distinguishing the samples with large differences, we conducted an on-line experiment in a tea factory and tried to monitor the smell variation during the manufacturing process. The results from the E-nose were similar to those of the sense of practitioners, which means that an E-nose has the possibility to replace the sensory function of practitioners in the future.

Proteomic analysis of “Oriental Beauty” oolong tea leaves with different degrees of leafhopper infestation

2020 ◽  
Vol 34 (15) ◽  
Author(s):  
Han‐Ju Chien ◽  
Man‐Miao Yang ◽  
Wei‐Chen Wang ◽  
Xiang‐Gui Hong ◽  
Yi‐Feng Zheng ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Tea Leaves ◽  
Oolong Tea

scholarly journals Aged leaves effect on essential components in green and oolong tea

2014 ◽  
Vol 3 (2) ◽  
pp. 54-58 ◽  
Author(s):  
MM Rahman ◽  
MA Kalam ◽  
MA Salam ◽  
MR Rana
Keyword(s):  
Ascorbic Acid ◽  
Green Tea ◽  
Biochemical Analysis ◽  
Ph Value ◽  
Tea Leaves ◽  
Oolong Tea ◽  
Essential Components ◽  
Tea Leaf

Tea leaf encompasses essential components like caffeine, polyphenol, lipid etc. The study was conducted to find out the essential constituents in green and oolong tea from aged tea leaves during the year of 2012. Tea leaves with different plucked aged were collected from Lackatoorah Tea Estate at sylhet district in Bangladesh. Collected leaves were processesed to make desirable samples for biochemical analysis in the laboratory of Department of Food Enginnering and Tea Technology, SUST. Results revealed that the essential constituents like moisture, caffeine, polyphenol, lipid, protein, ash, ascorbic acid, acidity and pH value in green tea made from different aged leaves were found slightly higher than oolong tea, ranged from 6.38±1.06 to 3.49±0.59%; 4.91±0.82 to 1.49±0.24%; 30.88±5.15 to 18.23±3.04%; 7.50±1.25 to 9.58±1.59%; 13.15±2.19 to 17.33±2.88%; 3.87±1.65 to 7.86±1.31%; 48.4±8.05 to 21.3±3.55(mg); 2.13±0.68 to 1.18±0.19% and 5.52±0.11 to 5.97±0.18%, respectively. Similarly, the moisture, caffeine, polyphenol, lipid, protein, ash, ascorbic acid, acidity and pH value from different aged leaves were found in oolong tea from 6.19±1.04 to 2.98±0.49%; 4.68±0.78 to 1.11±0.19%; 20.89±3.48 to 8.23±1.37%; 6.40±1.07 to 9.13±1.52%; 13.03±2.17 to 17.19±2.86%; 3.44±0.58 to 7.57±1.27% 6.44±1.08 to 0.98±0.17 (mg); 2.02±0.34to 1.02±0.17% and 5.53±0.11 to 5.97±0.20%, respectively. Therefore, young tea leaves (i.e. 5 to 8 days tea leaves) should be plucked for considering useful constituents in processed green tea and oolong tea. DOI: http://dx.doi.org/10.3329/ijarit.v3i2.17845 Int. J. Agril. Res. Innov. & Tech. 3 (2): 54-58, December, 2013

scholarly journals Crystal Structures of Flavone C-Glycosides from Oolong Tea Leaves: Chafuroside A Dihydrate and Chafuroside B Monohydrate

2019 ◽  
Vol 67 (9) ◽  
pp. 935-939
Author(s):  
Yasunori Iwao ◽  
Hitoshi Ishida ◽  
Shin-ichiro Kimura ◽  
Toshiyuki Wakimoto ◽  
Hiromu Kondo ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Tea Leaves ◽  
Oolong Tea

Specificity of Glycosidases from Tea Leaves toward Glycidic Tea Aroma Precursors

2001 ◽  
pp. 167-175 ◽  
Author(s):  
Akio Kobayashi ◽  
Kikue Kubota ◽  
Dongmei Wang ◽  
Takako Yoshimura
Keyword(s):  
Tea Leaves ◽  
Aroma Precursors

The Role of Diglycosides as Tea Aroma Precursors:  Synthesis of Tea Diglycosides and Specificity of Glycosidases in Tea Leaves

1997 ◽  
Vol 45 (7) ◽  
pp. 2674-2678 ◽  
Author(s):  
Sachiko Matsumura ◽  
Shunya Takahashi ◽  
Mariko Nishikitani ◽  
Kikue Kubota ◽  
Akio Kobayashi
Keyword(s):  
Tea Leaves ◽  
Aroma Precursors

scholarly journals Changes of phenolic compounds of tea leaves during Oolong tea process

2014 ◽  
Vol 17 (1) ◽  
pp. 67-75
Author(s):  
Tram Ngoc Nguyen ◽  
Oanh Ngoc Huynh ◽  
Hien Phuoc Phan
Keyword(s):  
Phenolic Compounds ◽  
Green Tea ◽  
The Other ◽  
Tea Leaves ◽  
Total Polyphenols ◽  
Oolong Tea ◽  
Other Hand ◽  
Green Tea Leaves

It was believed that provided photographs of changes of total polyphenols (TPP), tannin, theaflavins (TF), thearubigins (TR) contents and total colour liquids. Green tea leaves were going through the stages: fresh tea → withering → incubated 1 → aromatic spin 1 → incubated 2 → aromatic spin 2 →fried inactivated enzymes. Tea samples in the stages were provided by Cau Tre tea factory. Tea samples were divided into two groups: the activated and inactivated enzyme groups – microwave was applied to treated the activated enzyme one. Tea samples after the inactivation were conducted. The results showed that TPP and tannin contents generally decreased. Changes of theaflavin contents were contrast to tannin contents. On the other hand, theaflavin and thearubigin are the major polyphenols that determine on the quality of Oolong tea.

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