It is amazing and shocking to learn how many everyday food items are riddled with MSG. You can find it hiding under so many different names!
From Wikipedia:
MSG is only one of several forms of free glutamate used in foods. Free glutamate may also be present in a wide variety of other additives, including hydrolyzed vegetable proteins, autolyzed yeast, hydrolyzed yeast, yeast extract, soy extracts, protein isolate, "spices" and "natural flavorings." See the Truth in Labeling website for the full list. The food additives disodium inosinate and disodium guanylate are useful only in synergy with MSG-containing ingredients, and provide a likely indicator of the presence of MSG in a product.
For this reason, FDA considers labels such as "No MSG" or "No Added MSG" to be misleading if the food contains ingredients that are sources of free glutamate, such as hydrolyzed protein.[6]
In 1993, FDA proposed adding the phrase "(contains glutamate)" to the common or usual names of certain protein hydrolysates that contain substantial amounts of glutamate.[6] For example, if the proposal were adopted, hydrolyzed soy protein would have to be declared on food labels as "hydrolyzed soy protein (contains glutamate)."
In 1994, FDA received a citizen's petition requesting changes in labeling requirements for foods that contain MSG or related substances.[6] The petition asks for mandatory listing of MSG as an ingredient on labels of manufactured and processed foods that contain manufactured free glutamic acid. It further asks that the amount of free glutamic acid or MSG in such products be stated on the label, along with a warning that MSG may be harmful to certain groups of people (in much the same way products with aspartame have a warning for phenylketonurics). FDA has not yet taken action on the petition