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Monosodium Glutamate (MSG)

Characteristics Of Msg

At room temperature, MSG (C5H8NNaO4• H2O) is a salt, which typically exists as a white, odorless crystalline powder that is soluble in water and alcohol. It does not have a melting point per se, but it decomposes when it is heated. When crystals of MSG are created in a water solution, they develop in the shape of rhombic prisms.

The molecules of MSG can exist in two different forms known as isomers. These isomers are chemically identical, but physically different because their molecular structures are dissimilar. In fact, the elements on the two MSG isomers, known as stereoisomers, are arranged in such a way that if they were placed next to each other, they would appear as mirror images. The isomers of MSG have different physiological effects, and only one of them, known as the L form, has flavor enhancing properties.

Although MSG is tasteless by itself, it is a flavor enhancer that can be used to improve the taste of meat, fish, fowl, vegetables, and soup. It is said to provide a unique flavor that is neither bitter, sour, sweet, or salty. Typically employed at concentrations of 0.2-0.9%, it is used extensively by the food industry in canned, frozen, and dried foods and Oriental food. It has also been used, with sugar, to improve the palatability of bitter drugs.



Filer, L. J. Glutamic Acid: Advances in Biochemistry and Physiology. New York: Raven Press, 1979.

Othmer, Kirk. Encyclopedia of Chemical Technology. Vol. 2. New York: Wiley, 1978.

Perry Romanowski


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Chinese restaurant syndrome (CRS)

—A disease which involves symptoms of burning and numbness, believed to be caused by MSG in Oriental food.


—A mass of waste protein obtained from wheat or corn that is used as a raw material for producing MSG.


—A chemical reaction that involves breaking down the structure of a protein by the addition of water.


—Two molecules in which the number of atoms and the types of atoms are identical, but their arrangement in space is different, resulting in different chemical and physical properties.


—A chemical reaction between an acid and a base that results in the formation of a salt and water.

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Science EncyclopediaScience & Philosophy: Molecular distillation to My station and its duties:Monosodium Glutamate (MSG) - Characteristics of MSG