We have just gone through this with our DCP, so I sympathize with you. We go to a center, not in-home, so it's a little different. They were not terribly forthcoming with the ingredients in their foods and we guessed that was for a reason....
We made this list:
no high fructose corn syrup
no processed or powdered cheese or sauces
only natural meat and dairy products (i.e., no added hormones or antibiotics)
In the end, we decided to continue bring DDs food from home. After we made that decision, the daycare made us bring a note from the Dr saying that she approved that we only bring DDs food from home We have a great pedi who willing signed such a note, but it did make us mad that it was required