Monosodium Glutamate, in short MSG, or E621, in Polish glutaminian sodu, as a chemical that is often added to foods as a "flavor enhancer". What it actually does is increase the sensitivity to taste, especially saltiness.
In Poland, E621 is nearly always added to the following foods:
1. Ham, sandwich meat (Wędliny).
2. Sausage products (Kiełbasa).
3. Ready soup mixes and soup seasoning, both in dry form and liquid form.
4. Flavored chips (crisps per European English). Virtually anything other than plain salted has added E621.
5. Seasoning mixes, especially for meat.
Plus many other food products.
Some research supports that E621 has negative health effects. In particular increased blood pressure (hypertension) and irregular heart rhythm (Arrhythmia). Some individuals are more sensitive than others, reporting immediate reactions, while others feel no reaction at all.
The Polish food industry has defended the use of E621 (among other chemicals) claiming it was necessary to obtain an "authentic" or "classic" Polish flavor. I find this laughable since E621 came to Poland mainly after the fall of communism so nothing about it is authentic nor classic.
Some Polish companies however have chosen to buck the trend and go without artificial flavor enhancers like E621 - and I for one am a big fan of their products.
There is an actual commercial reason why the industry likes to use E621. It reduces the cost of the product. When MSG is added, it allows them to use less of every other seasoning ingredient.
I invite you to share your experience and feedback on this subject.