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

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ting-Shiang Tseng ◽  
Mei-Hui Hsiao ◽  
Po-An Chen ◽  
Shu-Yen Lin ◽  
Shih-Wen Chiu ◽  
...  

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.


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

Author(s):  
MM Rahman ◽  
MA Kalam ◽  
MA Salam ◽  
MR Rana

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


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

Author(s):  
Akio Kobayashi ◽  
Kikue Kubota ◽  
Dongmei Wang ◽  
Takako Yoshimura
Keyword(s):  

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

2016 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Mega Yulia ◽  
Devahimer Harsep Rosi

A research on the cytotoxic activity of several variants leaves of the soursop (Anona muricata Linn). Soursop leaf is processed into three kinds of tea leaves are green tea, black tea, oolong tea. Cytotoxic activity test was conducted using "Brine Shrimp Lethality Test". LC50 value of the three extracts of the leaves of the soursop is 102.32 ppm for ethanol extract of green tea, black tea 38.01 ppm and 63.09 ppm for oolong tea. Soursop leaf tea processing techniques can affect the cytotoxic activity.


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