When I was little, it was commonly believed that McDonald's used WORMS in their burger meat. Then, soybeans (which could be true?)
Are you actually trying to recreate the exact taste of Mcfood?? In all honesty, it would likely be cheaper to just go to McD's and get it. I'm sure their meat is sent to each restaurant already prepared, and I doubt HQ will willingly share recipes -- but who knows?!