Hydrolysed vegetable protein (HVP)
It's a "flavour enhancer" used in processed foods like soups, chilli, sauces, gravies, stews and some meat products like hot dogs. It's in some dips and snacks like potato chips and pretzels.
You'll also find it in some mass-produced vegetarian products made of soy.
Hydrolyzed vegetable protein (HVP) is produced by boiling foods such as soy, corn, or wheat in hydrochloric acid and then neutralizing the solution with sodium hydroxide. The acid breaks down the protein in vegetables into their component amino acids.
One of the amino acids in the dark-coloured liquid that's left is glutamic acid. Consumers are more familiar with glutamic acid in the form of its sodium salt - monosodium glutamate, or MSG.
A similar product - derived from dairy products - is hydrolyzed whey protein.