Cycling treatment of anaerobic and aerobic incubation increases the content of gamma-aminobutyric acid in tea shoots

gamma -Aminobutyric acid (GABA), a hypotensive compound, is formed from glu tamic acid under anaerobic condition in tea shoots. Glutamic acid was exhau sted in the first three hours of anaerobic incubation and the increase of G ABA stopped. After that, when tea shoots were released under aerobic condit ion, glutamic acid reproduced rapidly. After one hour of aerobic incubation , tea shoots were given three hours of anaerobic incubation again and then accumulated glutamic acid changed to GABA. The content of GABA increased mu ch more than usual anaerobic incubation. GABA was more in the tea stem than in the leaf.