11.01.03
Researchers from Iowa State University found that L-theanine, an amino acid found in green tea and associated with relaxing effects, may sometimes have a different composition in bulk commercial products. The findings of Dr. Daniel Armstrong, the Caldwell Professor of Chemistry at Iowa State University, are from a series of chemical analyses performed on several commercially available raw materials claiming to be pure L-theanine. Dr. Armstrong’s laboratory was the first to report on the chemical forms of L-theanine in brewed tea and tea leaves, published in the Journal of Agricultural and Food Chemistry in 2000. Dr. Armstrong said their method is very selective at separating out the D- and L-forms. The study findings are being submitted for presentation at a national scientific research conference and for publication in a peer reviewed journal. The study was sponsored by Taiyo Kagaku.