There is a chemical in McDonalds ketchup packets (not in the ketchup that you pump out of the big jars) that reacts with chemicals found in Burger King hamburgers and causes the meat to taste rancid and spoiled and smell awful.
Burger King responded and extended their attack into their Sweet & sour sauce, Mustard and Ketchup.
McDonalds also escalated its chemical warfare and now every pre-packaged sauce from both McDonalds and Burger King contains chemicals that react with the food from the other chain.
This has been going on for several years. There is a constant burger war going on where McDonalds and Burger King constantly try to change their burger's composition to render them safe against the other's sauces.
It makes me angry to know that we are eating this!
I've made the mistake of using a ketchup packet from McDonalds on a Burger King cheeseburger and I had to throw it away after only one bite!
My ex-wife's used to work for Sandoz pharmaceuticals in Palo Alto, CA and she heard from a coworker there that one of the project teams were doing that sort of work.
