Sources of MSG and 5-Nucleotides

Processed Foods Flavor Potentiators and Usage Levels 

Source From Maga, J.A., CRC Crit. Rev. Food Sci. Nutr., 18, 3, 1983. With permission. 

MSG is recovered from the ferment by first removing the cells followed by L-glutamate crystallization [11], The crystals are washed to remove impurities, decolorized, filtered, and further purified to yield a very pure L-glutamate. The productivity of this organism, optical purity of the product, and ease of isolation from the medium all have made fermentation the production method of choice. 

Maga [8] listed the following as commercial sources of the 5 -nucleotides (1) fresh muscle of marine fish, (2) degradation of RNA by 5 -phospho-diesterase, (3) fermentation to produce nucleotides followed by chemical phosphorylation to produce the 5 -nucleotides, (4) direct fermentation to yield 5 -nucleotides, (5) chemical decomposition of RNA to produce nucleotides followed by phosphorylation to yield 5 -nucleotides, and (6) a combination of procedures. 

FIGURE 11.4 Glutamic acid accumulation by a selected strain of Corynebacterium glutamicum. (From Nagodawithana, T.W., Savory Flavors, Esteekay Assoc., Milwaukee, 1995. With permission.) 

---