E numbered substances have question marks anyway for those careful with food intake. Monosodium glutamate E621 often called ‘flavour enhancer’ is something to be avoided I’ve heard. The highly flavoured salty taste is really good but if you like to watch what you eat apart from watching the Grand National cut this one out, or monitor it.
If you are one of those not bothered about what you eat ignore this but I know some people on here share my thoughts on what we eat.
Apparently it is camouflaged in many foodstuffs.
E621. Read the labels.