PROCESS FOR PURIFYING THEANINE

摘要

The present invention provides a process for purifying theanine from an aqueous solution having a dominant cation and comprising impurities. The process comprises the steps of: introducing the aqueous solution into a column in an amount of from 2 to 20% of the column volume, wherein the column is packed with a cation exchange resin of the same cation type as the dominant cation; then introducing an aqueous mobile phase having a pH of from 2.5 to 8.5 into the column thereby to elute a zone enriched in the impurities followed by a zone enriched in theanine; and then recovering at least one fraction of the zone enriched in theanine.