Monosodium glutamate (MSG) is the sodium salt of glutamic acid and can be found in a variety of foods, including tomatoes, mushrooms, seaweed, fish, cheese and other fermented food. While attempting to unleash the secret behind the tastiness of many Japanese broths / soups that are made of kombu, an edible seaweed, Prof. Kikunae Ikeda, was able to identify and isolate the major compound that is responsible for the tasty broth as MSG (Mouritsen & Styrbæk, 2014).

Since its discovery MSG has been used commercially in a variety of foods such as in savoury and sweet snacks, stock cubes, soups, ramen, gravy, stews and other convenience food.

MSG has previously been linked to "Chinese restaurant syndrome," which is blamed for headaches and other unpleasant symptoms. This has been proven to be a common MSG myth, as additional research has not supported these assumptions (Yamamoto et al., 2009; Mouritsen & Styrbæk, 2014). No such effects are observed when MSG is added to meals at typical concentrations, and when MSG is added to soup at high concentrations, the results of several blinded trials are unclear. The American Food and Drug Administration has designated MSG as "generally recognised as safe" (GRAS) (U.S. FDA, 2012). Whereas the European Union classifies it as a food additive, permitted in certain foods but with quantity restrictions (EFSA, 2017).