Now that product ingredient lists have become marketing bullets, here are two terms that I’ve found useful for thinking about them:

Ingrediant (with an ‘a’)

An item added to an ingredient list purely for its marketing effect, as opposed to any material qualities that it adds to the product.  For example, the vitamins that are added to shampoos.  (By analogy with surfactant, flavorant, colorant.)

Isochem

A more appealing synonym for a common ingredient.  For example, "evaported cane juice" for "sugar", or "hydrolyzed vegetable protein" for "monosodium glutamate (MSG)".