INS 422 is glycerol, also known as glycerine or glycerin, numbered E422 in Europe. It is a clear, odourless, syrupy liquid with a mildly sweet taste. Codex lists it as a humectant and thickener.
Glycerol forms the backbone of every fat and oil molecule. Food-grade glycerol is mostly obtained when fats and oils are split, for example in soap or biodiesel production, and then purified; it can also be made from petrochemicals. The source fat can be vegetable or animal, and a label usually does not say which.
As a humectant it attracts and holds water, so it stops soft confectionery from drying out and going hard during storage. In gummies like Cororo Grape Jelly it helps preserve the soft, chewy texture and adds a little sweetness of its own. Soft-baked goods and fillings use it for the same reason.
