... from glutamic acid through glutamate decarboxylase, GABA, a kind of natural non-protein amino acid, is an important neurotransmitter of the ... been applied to all kinds of tea beverages, dairy products, frozen food, wine, fermented food, bread, soup and other healthy and ... into the tea, beverages and milk products. 3. as the natural ingredients used in coffee, chocolate, apple juice, cocoa, yogurt, ...