Monosodium Glutamate (MSG) (C₅H₈NO₄Na) — Properties, Uses & Safety

Overview

Monosodium glutamate, commonly known as MSG, is the sodium salt of glutamic acid with the chemical formula C5H8NO4Na and a molar mass of 169.11 g/mol. It appears as a white crystalline powder that dissolves readily in water, dissociating into sodium ions (Na+) and glutamate ions. MSG is one of the most widely used food additives in the world, prized for imparting the savory umami taste — the fifth basic taste alongside sweet, sour, salty, and bitter. Umami was first identified by Japanese chemist Kikunae Ikeda in 1908, who isolated glutamate from seaweed broth and patented the production of MSG. Glutamic acid is a naturally occurring amino acid found abundantly in tomatoes, aged cheeses like Parmesan, soy sauce, mushrooms, and fermented foods. Commercially, MSG is produced by bacterial fermentation of sugars from starch or molasses. In the body, glutamate serves as a key excitatory neurotransmitter in the brain and plays roles in learning and memory. Despite decades of controversy, extensive scientific reviews by the FDA, WHO, and other agencies have found MSG safe for the general population at typical dietary levels. From a chemistry perspective, MSG is an excellent example of an amino acid salt, illustrating concepts such as zwitterion formation, acid-base chemistry, and ionic dissociation. Its production via fermentation connects to biochemistry and industrial chemistry topics. The compound also demonstrates chirality, as glutamic acid has L and D enantiomers, with only the L-form being biologically active. For students, MSG bridges organic chemistry, biochemistry, and food science, showing how a simple amino acid derivative can have profound effects on taste perception and spark global scientific debate.

IUPAC Name

sodium 2-amino-4-carboxybutanoate

CAS Number

142-47-2

PubChem CID

85314

Molecular Formula

C₅H₈NO₄Na

Molar Mass

169.111 g/mol

State at STP

solid

Appearance

White crystalline powder