Need a food-safe finish for a hammered copper fruit bowl

I made a hammered copper fruit bowl for my mom for Christmas, and put a heat patina on it. I've finished the outside with standard finishing wax, but it has a really toxic smell to it and I'm searching for a food-safe way to finish the inside (both to preserve the patina and to make it food-safe; I've been told raw copper isn't too safe for prolonged food exposure). Somebody suggested krylon matte finish, but warned it may be toxic. Any ideas?

The only safe way to serve food in your copper bowl is to use a glass insert. Never, never serve food from a copper container! Not only may your food be contaminated, the bowl may also be damaged or discolored by the food!

Glass insert is safest but thick tin plate is also safe.