INS 477 is propylene glycol esters of fatty acids, listed in Europe as E477, propane-1,2-diol esters of fatty acids. Codex lists it as an emulsifier. It is made by combining propylene glycol, a small food-grade alcohol, with fatty acids from edible fats or oils. The fat may be vegetable or animal, and labels rarely say which.
Its strength is aeration. Added to shortening, cake batters or whipped toppings, it helps fat crystals form in a way that traps and holds tiny air bubbles, giving a lighter, more even texture. It is usually combined with other emulsifiers rather than used alone.
Denma filled cookies show such a blend: the ingredient list names INS 477 alongside mono- and diglycerides (INS 471) and lecithin (INS 322 (i)), a combination often found in butter-rich biscuits and creamy fillings.
