Gamma-aminobutyric acid (GABA) has many
pharmacological functions including being a major inhibitory
neurotransmitter. Two comparative methods for
GABA production in rice grains as main food source in
Thailand were investigated in this study. Fermentation and
germination method were separately carried out using
seven selected local grain cultivars in northern Thailand.
Red yeast rice, obtained from the fermentation method,
gave the higher GABA concentration than the germinated
rice produced from the germination method in most rice
cultivars. The highest GABA concentration was 28.37 mg/
g at 3 weeks fermentation time of glutinous rice, O. sativa
L. cv. Sanpatong 1 cultivars, while germinated rice from
glutinous rice; O. sativa L. cv. Korkor6 (RD6) cultivars
contained the highest GABA concentration of 3.86 mg/g.
These results provide information for the basis of an
appropriate method for GABA production. The fermentation
produced higher GABA concentration but required
longer production period and red yeast rice was obtained as
product. On the other hand, the germination method yielded
rice grains with lower GABA but in more suitable form
for consumption. Both methods are considered to b