6254. Monosodium Glutamate

Nomenclature

CAS number: 142-47-2
l-Glutamic acid monosodium salt; sodium glutamate; Chinese seasoning; MSG; RL-50; Accent (Underwood); Aji-no-moto (Suzuki).
C5H8NNaO4; mol wt 169.11.
C 35.51%, H 4.77%, N 8.28%, Na 13.59%, O 37.84%.

Description and references

Prepn: K. Ikeda, S. Suzuki, GB 9440 (1910), C.A. 5, 836 (1910). Commercial prepn: P. R. Shildneck, US 2306646 (1942 to Staley Manuf.). Determn in food by HPLC: A. T. Rhys Williams, S. A. Winfield, Analyst 107, 1092 (1982); by LC: O.W. Lau, C. S. Mok, Anal. Chim. Acta 302, 45 (1995). Review of use and biological effects: Food Technol. 41, 143-154 (1987). Review: T. Kawakita, “l-Monosodium Glutamate (MSG)” in Kirk-Othmer Encyclopedia of Chemical Technology Vol. 2 (John Wiley & Sons, New York, 4th ed., 1992) pp 571-579. Review of toxicology: O. U. Eka et al., Biokemistri 4, 57-73 (1994). Book: Glutamic Acid: Advances in Biochemistry and Physiology L. J. Filer et al., Eds. (Raven Press, New York, 1979) 416 pp.

Chemical structure

Properties

White, practically odorless, free flowing crystals often as the monohydrate, dec 225°. Below -0.8°, crystallizes as a pentahydrate which upon filtration and exposure to air becomes the monohydrate. [α]20 -3.5° (10% soln in 5° Bé HCl). [α]D20 +25.16° (10g MSG/100ml 2N HCl). d20 (saturated water soln): 1.620. pH of 5% water soln: 6.8; of 3% soln (25°): 7.0. Soly at 20° (g/100g): 41.7 water. LD50 i.g. in mice: 19.9 g/kg (Eka).

Use

Flavor enhancer.