This technology has been created in Japan. Dr. Tsushida and his collaborators at the former MAFF National Research Institute of Tea (currently the National Institute of Vegetables and Tea Science) began developing GABA-rich tea in 1984 and successfully produced a new type tea in which almost all glutamic acid has been converted to GABA without changing the content of catechin or caffeine. They discovered a new method of tea fermentation, and found that a large amount of GABA accumulated in green tea through six to ten hours in anaerobic (oxygen-free) condition of fermentation. Oxygen in the atmosphere fermentation chamber was replaced with nitrogen. They examined further the GABA content of green, oolong and black tea made under anaerobic condition and found that GABA accumulated in all teas. Japanese scientists have shown great interest and attention to this new technology and in the late 1980s in Japan, this GABA tea was actively distributed as a commercial product for people with hypertension. It was found that the chemically synthesized GABA reduces blood pressure in experimental animals and humans. Further research demonstrated that GABA tea was also able to reduce the blood pressure in experimental animals and humans.
Although there is the experimental finding that exogenous GABA does not penetrate the blood–brain barrier, there are GABA receptors in the peripheral nervous system that may be reacting to the tea.
- Tojiro Tsushida, Toshinobu Murai, Masashi Omori, Jyunko Okamoto (1987). "Production of a New Type Tea Containing a High Level of gamma-Aminobutyric Acid". Nippon Nogeikagaku Kaishi. 61 (7): 817–822. doi:10.1271/nogeikagaku1924.61.817. Retrieved 2016-10-05.CS1 maint: Uses authors parameter (link)
- Masashi Omori, Toshiko Yano, Junko Okamoto, Tojiro Tsushida, Toshinobu Murai, Mitsuru Higuchi (1987). "Effect of Anaerobically Treated Tea (Gabaron Tea) on Blood Pressure of Spontaneously Hypertensive Rats". Nippon Nogeikagaku Kaishi. 61 (11): 1449–1451. doi:10.1271/nogeikagaku1924.61.1449. Retrieved 2016-10-05.CS1 maint: Uses authors parameter (link)
- Stanton, 1963
- Elliott & Hobbiger, 1959
- Abe Y, et al., Effect of green tea rich in gamma-aminobutyric acid on blood pressure of Dahl saltsensitive rats. Am J Hypertens. 1995, 8: 74–79
- Hakamata, 1990
- Lin et al., 2000
- Kuriyama K, Sze PY (January 1971). "Blood–brain barrier to H3-γ-aminobutyric acid in normal and amino oxyacetic acid-treated animals". Neuropharmacology. 10 (1): 103–108. doi:10.1016/0028-3908(71)90013-X. PMID 5569303.
- Sheng-Dun Lin, et al., Bioactive components and antioxidant properties of g-aminobutyric acid (GABA) tea leaves. LWT – Food Science and Technology Volume 46, Issue 1, April 2012, pp. 64–70
- Hsueh Fang Wang, et al., Comparison of bioactive components in GABA tea and green tea produced in Taiwan. Department of Food Science, National Chung Hsing University, 250 KuoKuang Road, Taichung, Taiwan 402, ROC. Food Chemistry (Impact Factor: 3.39). 06/2006; 96(4):648–653. DOI: 10.1016/j.foodchem.2005.02.046
|This tea-related article is a stub. You can help Wikipedia by expanding it.|