Both green and black tea, and in fact, oolong and white tea as well, come from the same plant, Camellia sinensis. The use of tea is likely to have originated in China during the Shang Dynasty (1600-1046 BC). During that time, only the leaves were steeped, whereas the idea of incorporating additional ingredients came later when tea was used as medicine1.
So what is the difference between green and black tea? The answer has to do with the processing and oxidation. Green tea is made by pan-firing or steaming the leaves, which prevents the leaves from oxidizing and helps them retain their green color and delicate, fresh flavor. In contrast, black tea is processed in part by rolling, tearing, or crushing the leaves, which allows oxidation to occur (not unlike the way an apple turns brown once the skin is pierced). The leaves darken and develop a stronger flavor as they dry.1, 2
Micro-CT Scan of Green and Black Teas
The micro-CT scanning of our green and black tea samples helps visualize what we know about the manufacturing process. When looking at the 3D image of the green tea, there are larger pieces that more resemble leaf structure on a small scale. Investigation of the 2D axial slice image also shows longer segments of the leaf portions and a more intact structure. The black tea 3D image and 2D axial slice show smaller, more fragmented pieces (see Figures 2 and 3).
This demonstrates just one of many applications where comparisons can be made with micro-CT imaging. We hope you found this image of the month interesting and something you will think of the next time you have a tea break. If you have an image of the month sample that you would like us to scan, let us know by calling Brandon Walters at 610-366-7103 or e-mailing brandon@microphotonics.com.
BOTH SCAN SPECIFICATIONS
System
Voltage
50kV
Current
200µA
Pixel Size
4um
Rotation Step:
0.3
Scan Time
00:33:29 (HH:MM:SS)
Software
NRecon, DataViewer, CTVox
Location
Micro Photonics Imaging Laboratory, Allentown, PA
WORKS CITED
- http://www.todayifoundout.com/index.php/2015/04/whats-difference-green-black-tea/
- http://www.thekitchn.com/whats-the-difference-between-black-and-green-tea-tea-essentials-200614
Conclusion
This demonstrates just one of many applications where comparisons can be made with micro-CT imaging. We hope you found this image of the month interesting and something you will think of the next time you have a tea break. If you have an image of the month sample that you would like us to scan, let us know by calling Brandon Walters at 610-366-7103 or e-mailing brandon@microphotonics.com.
BOTH SCAN SPECIFICATIONS
System
Voltage
50kV
Current
200µA
Pixel Size
4um
Rotation Step:
0.3
Scan Time
00:33:29 (HH:MM:SS)
Software
NRecon, DataViewer, CTVox
Location
Micro Photonics Imaging Laboratory, Allentown, PA
WORKS CITED
- http://www.todayifoundout.com/index.php/2015/04/whats-difference-green-black-tea/
- http://www.thekitchn.com/whats-the-difference-between-black-and-green-tea-tea-essentials-200614