Monosodium glutamate

Monosodium glutamate (MSG), also known as sodium glutamate, is a sodium salt of glutamic acid. MSG is found naturally in some foods including tomatoes and cheese in this glutamic acid form, and is used in cooking as a flavor enhancer that intensifies the umami flavor of food, as naturally occurring glutamate does in foods such as stews and meat soups.

MSG was first extracted in 1908 by Japanese biochemist Kikunae Ikeda, who tried to isolate and duplicate the savory taste of kombu, an edible seaweed used as a broth (dashi) ingredient in Japanese cuisine. It also balances, blends, and rounds the perception of other tastes. MSG, along with disodium ribonucleotides, is commonly used and found in stock (bouillon) cubes, soups, ramen, gravy, stews, condiments, savory snacks, etc.

The U.S. Food and Drug Administration has given MSG its generally recognized as safe (GRAS) designation. It is a popular misconception that MSG can cause headaches and other feelings of discomfort, known as "Chinese restaurant syndrome". Several blinded studies show no such effects when MSG is combined with food in normal concentrations, and are inconclusive when MSG is added to broth in large concentrations. The European Union classifies it as a food additive permitted in certain foods and subject to quantitative limits. MSG has the HS code 2922.42 and the E number E621.