Application Note: Analysis of Amino Acids in Green Tea

Analysis of Amino Acids in Green Tea Using Automatic Pretreatment Function of Integrated LC System Prominence (TM)-i

Green tea, that has been commonly enjoyed by Japanese people since centuries ago has also attracted attention as a health food in recent years. Among the amino acids contained in green tea, the content of theanine is the largest.⁽¹⁾ Theanine is the main umami (flavor enhancing) compounds in green tea, and is also expected to have various functional effects including relieving feelings of stress, aiding sleep, etc. In addition to theanine, green tea also contains a number of other compounds that are of interest as umami useful compounds for health.

The application focuses on four compounds of sencha (middle grade green tea) and hojicha (roasted green tea), the umami compounds theanine and glutamic acid (Glu), and the healthrelated compounds arginine (Arg) and γ-aminobutyric acid (GABA), and introduces an analysis by fluorescence derivatization with o-phthalaldehyde (OPA) using the automatic pretreatment function of the integrated LC system Prominence^TM-i.