Monosodium glutamate (MSG, also known as sodium glutamate) is the sodium salt of glutamic acid, one of the most abundant naturally occurring non-essential amino acids. Monosodium glutamate is found in tomatoes, Parmesan cheese, potatoes, mushrooms, and other vegetables and fruits.

Chemical formula : C₅H₈NO₄Na

E number : E621

MSG is freely soluble in water, but it is not hygroscopic and is insoluble in common organic solvents . It is generally stable under food-processing conditions. MSG does not break down during cooking and, like other amino acids, will exhibit a Maillard reaction (browning) in the presence of sugars at very high temperatures.A white, odorless, crystalline powder, in solution it dissociates into glutamate and sodium ions.

MSG is used in the food industry 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 can be used to reduce the intake of sodium, which contributes to hypertension, heart disease, and stroke. With appropriate MSG use, salt can be reduced by 30 to 40% without a perceived reduction in saltiness.

wikipedia