recipes aren't patentable, only designs of machines/software. source code is copyrighted, as well as their recipes as they wrote them down. But if I wrote down:

Burger:
1 bun
1 meat(?) patty
1 slice of onion
2 pickles
etc..

I wouldn't be violating their copyright on their recipe.. the 11 herbs and spices in the KFC chicken isn't copyrighted.. that's why it's secret.. so noone can use them.. revealing trade secrets by an employee would be a contract violation..