Note Even if you know the ingredients in a prepared food--such as grated apples--you must see identifiable pieces in order to say a specific blessing (borei pri ha'eitz, borei pri ha'adama...). If no ingredients are visually identifiable, you must say she'hakol (or possibly borei minei mezonot).
Example Say borei pri ha'adama on a potato kugel with coarsely ground potatoes; if the potatoes are pulverized, say she'hakol.