Institute of Fruit Tree and Tea Science of the National Agriculture and Food Research Organization or NARO, headquartered at Tsukuba city in Ibaraki prefecture, found that condensed essences of amino acid, cate-chin and caffeine, making up green tea’s taste of good flavor and bitterness, are extracted into hot water from green tea leaves produced in Japan much more than from those in China.
NARO’s Institute hopes that green tea manufacturers will be able to publicize a characteristic feature of tea leaves produced in Japan with a quality of better extraction of essences in the international green tea market.
The Institute has made a physical and chemistry research to find out differences between 17 kinds of high-quality green tea manufactured in China and 9 kinds of green tea produced in Japan. For instance, three grams of each green tea was put into boiling distilled water and extracted for two minutes.
The research showed a result that green tea leaves produced in Japan distinctly differ in higher concentration of essences extracted in the hot water such as amino acid, cate-chin and caffeine than those leaves processed in China.
It is supposed that this difference, a higher extraction by Japanese green tea, comes from its unique methods of manufacturing that is characterized with two phases of processing, namely steaming and twisting of tea leaves.