What is sodium glutamate?

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

MSG was first prepared in 1908 by Japanese biochemist Kikunae Ikeda, who was trying to isolate and duplicate the savory taste of "kombu", an edible seaweed used as a base for many Japanese soups. MSG balances, blends, and rounds the perception of other tastes.

The U.S. Food and Drug Administration has given MSG its generally recognized as safe (GRAS) designation. It is a popular belief that MSG can cause headaches and other feelings of discomfort, known as "Chinese restaurant syndrome", but 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 29224220 and the E number E621.