PRODUCTION OF THEANINE

PROBLEM TO BE SOLVED: To simply and efficiently obtain theanine as a main component of flavor of green tea, useful for a nutritious food, taste improvement, etc., by reacting pyroglutamic acid, sodium pyroglutamate, etc., with an ethylamine under an alkali condition. SOLUTION: Pyroglutamic acid and/or sodium pyroglutamate is reacted with a solution of an ethylamine hydrochloride and/or ethylamine under an alkali condition of pH 10-13 in the presence of cyclodextrin of 1-10 times as much as pyroglutamic acid and/or sodium pyroglutamate etc., with an ethylamine in an aqueous medium in a closed container at 65 deg.C for two days under stirring to simply and efficiently give the subjective theanine (L-γ- glutamylethyamide) as a main component of flavor of green tea, useful for producing a nutritious food by mixing with various foods, taste improvement, etc.