What it is
Protein boiled in acid (or enzymes) until it surrenders its glutamate. A flavor enhancer that gets to dress as an ingredient.
Why your biology objects
Hydrolysis breaks protein into free amino acids including glutamate — the same umami trick as MSG, plus a risk of chloropropanol (3-MCPD) byproducts when the acid process is used. Reads as "protein," works as a flavor enhancer.