I shy away from synthetic MSG and any food additive made in a chemical factory. Any organic chemist is aware of side-chain reactions-the chemicals you don’t want are often not good for you. In synthesis, if the MSG is made from Acrylonitrile, I really don’t trust it; look up Acrylonitrile. It is very poisonous. So, you are trusting factories to produce pure MSG, with no accidental, other ingredients.
(Fermented MSG and) MSG containing products usually start with food, and there are plenty of those to choose from: Soy sauce, Miso, Katsuobushi, Kelp, Tomatoes, Anchovies, Tianjin Preserved vegetable (can be home-made), beef stock, Fish sauce, Fermented Black beans, etc. I’d rather add another level of flavor, along with naturally-occurring MSG, than trust a factory made, synthetic product. If one can confirm the MSG is, indeed made/isolated via fermentation, the primary method, that is likely to be safe.
