McDonald's restaurants have changed the recipe for their hamburgers after TV chef Jamie Oliver pressured the fast food giant to remove a processed food ingredient, ammonia hydroxide, that he called "pink slime."

Oliver shocked TV audiences by showing them the raw "pink slime" produced in the ammonia hydroxide process: "Why would any sensible human being want to put ammonia-filled meat into their children's mouths? The great American public needs to urgently understand what their food industry is doing."

After months of campaigning on his television show 'Jamie's Food Revolution,' McDonald's abandoned the beef filler from its burger patties.

US Department of Agriculture microbiologist Geral Zirnstein agreed with Jamie that ammonia-hydroxide agent should be banned: "I do not consider the stuff to be ground beef and I consider allowing it in ground beef to be a form of fraudulent labelling."

Todd Bacon, Senior Director of U.S. Quality Systems and Supply Chain with McDonald's, said: "The decision to remove BPI products from the McDonald’s system was not related to any particular event, but rather to support our effort to align our global beef raw material standards. McDonald's complies with all government requirements and food safety regulations."

Burger King and Taco Bell have earlier bowed to pressure and removed ammonia hydroxide processed ingredients from their products.