Table 4.

Optimized parameters for GABA-enriched beverage production.

Processing Stage	Optimized Condition
Raw material	Suijing 309 brown rice
Germination	4 h soaking (RT) + 40 h sprouting (30 °C, rinsing every 2 h)
Slurry preparation	Rice-to-water ratio 1:2 (w/v)
Liquefaction	α-amylase 30 U/g, 80 °C, 40 min
Saccharification	Glucoamylase 75 U/g, 60 °C, 1 h
Fermentation consortium	10-strain Culture J (Lactobacillus and Bifidobacterium consortium)
MSG supplementation	0.25% (w/v)
Inoculum size	4% (w/v)
Cofactor addition	Pyridoxine hydrochloride 10 μmol/L
Fermentation	37 °C, 24 h