Abstract: A technique for highly efficient production of ?-amino butyric acid (GABA) using mochi barley of the group of mules barley, as a raw material. The technique converts glutamic acid into GABA due to the glutamate decarboxylase contained in the mochi barley so GABA-mochi barley grains and GABA-mochi barley bran and GABA-containing bran supernatant can be produced highly-efficiently by mixing mochi barley grains, which have been polished in a barley milling device to an extent of 2% or more and less than 20%, with a glutamic acid solution, which has a concentration of 0.1 to 3% and a pH value of 2 to 9, and soaking the barley in the solution at room temperature for 1 hour or more to overnight or, after soaking in the solution similarly for 1 hour or more to overnight, draining the barley grains, and keeping it overnight at room temperature.

Abstract: Provided is a technique for highly efficient production of ?-amino butyric acid (GABA) using mochi barley belonging to the group of mules barley as a raw material. By using this technique, in particular, GABA-mochi barley grains and GABA-mochi barley bran, each containing GABA, and GABA-containing bran supernatant can efficiently be mass-produced especially from mochi barley. The most remarkable characteristics of the aforesaid technique is that glutamic acid is converted into GABA due to the action of glutamate decarboxylase contained in the mochi barley so that GABA-mochi barley grains and GABA mochi barley bran, each containing a large amount of GABA, and GABA-containing bran supernatant can be produced highly-efficiently by mixing mochi barley grains, which have been polished in a barley milling device to an extent of 2% or more and less than 20%, with a glutamic acid solution, which has a concentration of 0.