3.2. Production and characteristics of fermented GABA soya milk
In order to produce fermented GABA soya milk (GABA soya yogurt), germinated soybean with enhanced levels of GABA and some free amino acids was produced (Table 1). The germinated soybean extract was used to prepare a fermentation substrate solution. Starter strains including the L. brevis OPY-1 were inoculated into substrate solution, which was again incubated somewhere between 20 h and 24 h to produce the final product. The initial viable bacterial number of the yogurt could not be recorded between 0 h and 4 h due to a short incubation term, but remarkably increased by a time-dependent manner between 16 h and 20 h of fermentation. Maximum bacterial numbers were recorded as 4.4£108
colony forming units per ml of sample at 20 h of fermentation.