... glutamate decarboxylase, GABA, a kind of natural non-protein amino acid, is an important neurotransmitter of the central nervous system for ... food industry. It has been applied to all kinds of tea beverages, dairy products, frozen food, wine, fermented food, bread, ... directly adding into the tea, beverages and milk products. 3. as the natural ingredients used in coffee, chocolate, apple juice, cocoa ...