Accumulation of GABA in Brown Rice by High Pressure Treatment

Abstract

GABA has attracted considerable attention as an inhibitory amino acid which lowers blood pressure in mammals. We focused on the fact that GABA occurs naturally in brown rice and endeavored to manufacture an easy-to-cook processed brown rice with an increased GABA accumulation. High pressure was utilized to manufacture this processed brown rice. The following points were discussed in this report. After 400 MPa pressure treatment by soaking, the water content in the brown rice increased in comparison with the control rice. Eighteen point three mg GABA was extracted from 100 g dried brown rice soaked for 18h at 25°C after 400 MPa pressure treatment, on the other hand 10.8 mg GABA was extracted from the control rice. Both the amount of lysine which was a limiting amino acid and several free amino acids increased in the brown rice by pressure treatment and soaking.