Abstract:

The VB6 and CaCl2 concentration and pH of citric acid atomized liquid for γ-aminobutyric acid (GABA)
accumulation in activated brown rice were optimized by single-factor and orthogonal array experiments. Besides, the
changes in glutamate decarboxylase (GAD) activity and main component contents of activated brown rice were studied.
Results showed that the optimum atomized liquid contained 2 mmol/L VB6 and 10 mmol/L CaCl2 at pH 3.5. Under these
conditions, GABA content of activated brown rice reached 7.67 mg/100 g, which was a 2.74-fold increase over that of
raw brown rice. During the activation process, the contents of free amino acids, reducing sugar and GAD activity were all
increased, while the contents of both soluble protein and starch were decreased. Correlation analysis showed that the content
of GABA was significantly correlated with the contents of Glu, free amino acids and soluble protein, respectively.

Key words: activated brown rice, γ-aminobutyric acid, pH, VB6, CaCl2