Origin
Monosodium glutamate is the salt of glutamic acid, which belongs to the non-essential amino acids. The property of monosodium glutamate as a flavor enhancer was first discovered at the beginning of the 20th century in Japan. Back then, what we now know under the designation E 621 was still extracted from the algae Kombu. Today, there are other production methods for use in industrial food production. So, E 621 is produced from glutamic acid (E 620) and sodium hydroxide (E 524) with the help of microorganisms.
Usage
E 621 is generally permitted for foods but is limited to a maximum amount of 10g/kg, though dosages of about 2g/kg are sufficient in practice. E 621 can be found in: Snack items, spices, soups, sauces, meat and vegetable products, and ready meals.
Risks
For a long time, monosodium glutamate was considered the trigger of so-called Chinese Restaurant Syndrome, which is accompanied by nausea, headaches, and dizziness. No connection could be confirmed in clinical studies to date. E 621 is therefore considered safe.