Monosodium glutamate contains a single amino acid from glutamic acid and is not considered crude protein content. It is insoluble, and not hygroscopic in common organic solvents either. Responds well to processing, as it does not decompose when cooked. In the presence of sugar, it changes its color to brown when high temperatures are also applied.

It is usually available as a monohydrate, a white crystalline powder, odorless and soluble in water.