MSG is processed (manufactured) free glutamate that has been made in food processing or chemical plants and/or created by fermentation. In every case, the free glutamate that has been manufactured or created by fermentation is accompanied by unwanted byproducts of manufacture referred to as impurities One of those impurities is D-glutamic acid (D-glutamate).
The point to remember is that man-made free glutamate contains both L-glutamate and D-glutamate. In contrast, the glutamate in unadulterated fruits, grains, vegetables, and in the human body, isn’t manufactured. It's L-glutamate, only.
MSG can be produced from fruits, vegetables, grains, fish, meat, or poultry that contain protein, or from bacteria. When used in pharmaceuticals it is called a pharmaceutical. When used in food, it is called a food.
Unprocessed/unadulterated/unfermented protein in any meat, fish, fruit, grain, vegetable etc., contains L-glutamate but no D-glutamate.Prior to 1957, monosodium glutamate was produced by extracting glutamic acid from protein. Some monosodium glutamate is still made that way. But since 1957, monosodium glutamate has been produced using genetically modified bacteria (genetically modified organisms or GMOs), that secrete glutamic acid through their cell walls.
Unprocessed/unadulterated/unfermented protein in any meat, fish, fruit, grain, vegetable etc. does not contain MSG.
Unprocessed/unadulterated/unfermented mushrooms and tomatoes contain L-glutamate, but they do not contain D-glutamate. They do not contain MSG.
Monosodium glutamate contains processed free glutamate (MSG).
Processed free glutamate (MSG) can be extracted from any food that contains protein. Similarly, when any protein is fermented, MSG will be produced.
The key to understanding MSG lies in understanding six facts:
1) MSG is a product (something manufactured or processed), not a substance found in nature.Ingredients that contain MSG are often included in (added to) processed foods. MSG can also be generated during a product’s processing.
2) Regardless of the way in which it is produced, MSG contains unwanted by-products of production -- substances referred to as impurities.
3) MSG causes adverse reactions in people who ingest amounts that exceed their tolerances for the substance.
4) Unadulterated, unprocessed, unfermented protein, which contains glutamate does not cause adverse reactions.
5) MSG causes brain damage with subsequent endocrine disorders and adverse reactions when fed in quantity to the very young, whose blood-brain barriers are not yet fully developed.
6) Glutamate bound up in protein with other amino acids when fed to the very young, does not cause brain damage, no matter how much is ingested.