Nobody knows. Coca Cola lists most ingredients, but the secret sauce is listed as "Natural Flavors". That's where all the heavy flavor science in conducted and not just in Coca Cola. Most engineered foods in the US have "Natural Flavors" listed. The FDA, in their infinite wisdom, has decided that any number of artificial and engineered compounds qualify an "Natural Flavors" and they don't have to be disclosed. Some people I've spoken to think this is a result of lobbying from the major food manufacturers who want to make their products more "addictive".

I love America and I think Europe is backwards in many, many ways. This isn't one of those ways. I wish we had European-style food purity laws. The only way to guarantee your food hasn't been messed with or "adulterated" or "enriched" in some way is to skip the stores entirely and buy straight from a local farmer.