Additional reports attempted to look at this.In 1986, FDAs Advisory Committee on Hypersensitivity to Food Constituents concluded that monosodium glutamate poses no threat to the general public but that reactions of brief duration might occur in some people. Other reports have given the following findings:

The 1987 Joint Expert Committee on Food Additives of the United Nations Food and Agriculture Organization and the World Health Organization placed monosodium glutamate in the safest category of food ingredients. A 1991 report by the European Communitys (EC) Scientific Committee for Foods reaffirmed monosodium glutamates safety and classified its "acceptable daily intake" as "not specified", the most favorable designation for a food ingredient. In addition, the EC Committee said, "Infants, including prematures, have been shown to metabolize glutamate as efficiently as adults and therefore do not display any special susceptibility to elevated oral intakes of glutamate." Legislation in effect since June 2013 classifies glutamic acid and glutamates as salt substitutes, seasonings, and condiments with a maximum level of consumption of 10g/kg expressed as glutamic acid. European Union
Following the compulsory EU-food labeling law the use of glutamic acid and its salts has to be declared, and the name or E number of the salt has to be listed. Glutamic acid and its salts as food additives have the following E numbers: glutamic acid: E620, monosodium glutamate: E621, monopotassium glutamate: E622, calcium diglutamate: E623, monoammonium glutamate: E624, and magnesium diglutamate: E625.
In 1907, Japanese researcher Kikunae Ikeda of the Tokyo Imperial University identified brown crystals left behind after the evaporation of a large amount of kombu broth as glutamic acid. These crystals, when tasted, reproduced the ineffable but undeniable flavor detected in many foods, especially seaweed. Professor Ikeda coined the term umami for this flavor. He then patented a method of mass-producing the crystalline salt of glutamic acid known as monosodium glutamate. Isomers
Further research into the compound has found that only the L-glutamate enantiomer has flavor-enhancing properties. Manufactured monosodium glutamate consists to over 99.6% of the naturally predominant L-glutamate form, which is a higher proportion of L-glutamate than can be found in the free glutamate ions of fermented naturally occurring foods. Fermented products such as soy sauce, steak sauce, and Worcestershire sauce have levels of glutamate similar to those in foods with added monosodium glutamate. However, 5% or more of the glutamate may be the D-enantiomer. Nonfermented naturally occurring foods have lower relative levels of D-glutamate than fermented products do. Taste perception
Glutamic acid stimulates specific receptors located in taste buds such as the amino acid receptor T1R1/T1R3 or other glutamate receptors like the metabotropic receptors (mGluR4 and mGluR1), which induce the flavor known as umami. This is classified as one of the five basic tastes (the word "umami" is a loanword from Japanese; it is also referred to as "savory" or "meaty"). The flavoring effect of glutamate comes from its free form, in which it is not bound to other amino acids in protein.