This is a continuing story on the 5/24 Ming-Jeng 名間 trip and I am trying to do my best to capture what have learned from tea farmers' presentation. The following notes concerns about the effects of tea processing on the nutrition value of a red tea.
Nutrition values of tea originate from its catechin and theanine. Catechins are types of antioxidant. Green tea has substantially higher catechin contents than the red tea or black tea because green tea has lower level of fermentation (oxidation). Catechin contents in the red tea are controlled by a process called blanching (殺菁). This process involves heating the tea leaves either by frying or by steaming. The heating process can effectively kill the enzyme to stop subsequent fermentation.
Theanine is an amino acid (Its structure is shown on top) that is known to reduce mental stress. A Japanese tea technician, Mr. Yokogoshi, accidentally discovered in 1998 that theanine could be abundantly produced when tea leaves was nitrogen-blanketed overnight.
Photo on the left shows the equipment for nitrogen blanket in the organic tea farm at Ming-Jeng 名間.
The tea products produced at Ming-Jeng went through both the blanching (殺菁) and the nitrogen-blanketed technique. They are high-quality red tea.
No comments:
Post a Comment