Method for extracting theanine from tea

Abstract

The process of extracting theanine from tea includes the following steps: soaking tea with deionized water to obtain extracted solution; exchange absorbing of the extracted solution with cationic resin and elution with ammonia water to obtain theanine eluate; and decompression evaporating theanine eluate to obtain coarse theanine product. The present invention can utilize various kinds of tea material in extracting theanine, and has simple operation, low cost and no environmental pollution. The coarse theanine product is suitable for further processing and has purity of 10-30 %.

Description

technical field

[0001] The invention relates to a method for extracting theanine from tea leaves. Background technique

[0002] Amino acid in tea is an important component of its quality. The system is named N-ethyl-γ-L-glutamine (N-ethyl-γ-L-glatamine). Theanine is an effective flavoring substance in green tea. The content of theanine directly determines the quality of tea: no matter what kind of tea, theanine accounts for more than 50% of the free amino acids in tea, and the content of theanine in dry tea is about 1%-2%. Theanine is the ethylamine inducer of glutamic acid. It is synthesized from glutamic acid and ethylamine in the roots of tea trees, transported to the leaves for storage through the trunk, and converted into catechins under sunlight. In 1950, Mr. Shuto extracted and refined theanine from tea leaves for the first time, and determined its chemical structure (Zhao Danchao Asahi's domestic and foreign research status of theanine Food Science 2002.23 (5) 145...