Abstract:

In order to provide theoretical references for the deep development of millet, γ-Aminobutyric acid (GABA) accumulation in foxtail millet was explored through analyzing the change of major nutritional components and GABA content during the germination of millet. Dynamic changes of free amino acids, soluble proteins, glutamic acid, GABA content and glutamate decarboxylase (GAD) activity in germinated millet were investigated by the treatment of hypoxic ventilation. Results showed that sprout length of germinated millet were increased under hypoxic ventilation, however, the sprout length was still lower than that of the control; the content of free amino acids exhibited a rapid increase and higher than that of the control; the content of soluble proteins exhibited an initial increase and then a decrease, and lower than that of the control; an increase in glutamic acid content during first 24 h treatment of hypoxic ventilation and a following decrease were observed; GAD activity revealed a trend of initial increase and following reduction, and markedly higher than that of the control; GABA content revealed an increase during 48 h treatment of hypoxic ventilation and following decline. The maximal content of GABA was 24.32 mg/100g FW, which were 4.78 folds compared with pre-treatment, and higher 87.51% than the control at the same treatment time. These investigations indicated that hypoxic ventilation significantly improved GABA content of germinated millet, and GABA content exhibited a significantly positive correlation with free amino acids and GAD activity.

Key words: germinated foxtail millet, hypoxic ventilation, γ-aminobutyric acid, essential substance