Description
This is an enzymatic method for the quantitative determination of L-glutamic acid and monosodium glutamate in food. The method can be used for different kinds of food e.g. meat products, sausages, dried soups, bouillon cubes and liquid foods. 2. PRINCIPLE In the presence of the enzyme glutamate dehydrogenase (GIDH), L-glutamic acid is oxidatively deaminated by nicotinamide-adenosine dinucleotide (NAD) to 2-oxoglutarate (1). In the reaction catalyzed by diaphorase (2) the NADH thus formed reduces iodonitro tetrazolium chloride (INT) to a formazan which is measured spectrophotometrically in the visible range at 492 nm.