To establish a new method of processing germinated brown rice (GBR), we processed grain of cultivars with a large germ by soaking and gaseous treatment. After soaking for 3 h and gaseous treatment for 21 h at 35 degrees C, the content of gamma-aminobutyric acid (GABA) in GBR (24.9 mg/100 g) was higher than that by the conventional soaking method (10.1 mg/100 g). Although the number of microorganisms on the surface of the GBR increased during soaking, steaming for 20 min and ethanol treatment for 3 min completely sterilized the GBR and did not reduce the amount of GABA. (c) 2005 Elsevier Ltd. All rights reserved.