Most people have. Few know why it's there. The answer begins with one of chemistry's favorite problems: Oil and water don't mix. Chocolate, margarine, salad dressings, infant formula, and countless other foods all contain ingredients that naturally separate.
Left alone, they would form layers, become grainy, or lose their smooth texture. Nature solved this problem long before food scientists did. Soy lecithin is rich in phospholipids—remarkable molecules with two very different personalities.
Global Chemical Database