Theanine is a unique amino acid component in tea. It is a substance that exists in nature. It accounts for about 50% of the total free amino acids in a tea plant. Theanine promotes releasing dopamine from the central nervous system of the brain to generate a sedative effect and facilitates the brain to produce alpha waves. Theanine makes a feeling of relaxation and joy to the human body, so it is known as "happiness amino acid".
Therefore, in addition to ingesting catechins with antioxidant effects, theanine is also a functional ingredient that cannot be ignored. In order to understand the distribution of theanine in the tea better, pick six leaves with one bud and separate the leaves and stems. After being freeze-dried and grounded, extract in hot water at 90˚C for 20 minutes and determine the content of theanine in the extracted liquid with HPLC.
The research result shows:
The leaves: the very top leaf with one bud contained the most theanine (12.46 mg / g), while the sixth leaf contained the least (1.98 mg / g).
The stems: the second stem site had the highest content (67.16 mg / g), the first stem site had the second high ( 62.18 mg / g), and the fifth stem site had the least (20.29 mg / g).
The content of theanine in tea stems is much higher than that in leaves. The first and second stems are 5 times as much as one leaf with one bud, the third stem is 4 times, even the fourth and fifth stems are 2 times. It shows that the theanine content in tea stems is quite amazing.
This result is consistent with the research results conducted by Director Wu Zhenduo and Ye Suqing (1976): The content of theanine in the upper stem is higher than that in the lower stem (upper stem: 43.20 mg / g, lower stem: 38.93 mg / g). The theanine content in the lower stem is even higher than the top leaf with one bud (8.59 mg / g), and the content in the fourth leaf is the least (6.57 mg / g).
In addition, the caffeine content in tea stems was 1/2 to 1/10 of the leaves. The first leaf had the highest caffeine content (54.42 mg / g), and the second to sixth leaves had caffeine content of about 40 mg / g. The caffeine content in the first stem was about 1/2 (22.44 mg / g) of the leaves, and about 1/4 (9.72 mg / g) in the second stem, which decreases in order.
In general, tea stems are removed during the refining process of tea leaves, then pure tea stems become cheap by-products. However, even the fourth and fifth stems, the theanine content is still abundant. Drinking tea made from tea stems can ingest more theanine and reduce caffeine intake accordingly. Does this affordable stem tea with full ingredients make you all excited?
Enjoy your tea.
Source from: Tea Newsletter, Issue 102, 2017 from TRES
Translated and edited by Adm./jLteaco, All Rights Reserved.