Just read the paragraph below as to what this stuff is and where it comes from.
“Pink slime” is bits of meat and muscle salvaged from slaughterhouse floors that are treated with a pink chemical to kill any dangerous pathogens. According to an earlier report by msnbc.com, the unappetizing pink goo is widely used in the food industry as an anti-microbial agent in meats and as a leavener in bread and cake products. It’s regulated by the U.S. Agriculture Department, which classifies it as “generally recognized as safe.” Nevertheless, McDonald’s, have said they are pulling the infamous “pink slime” from their hamburgers.
via Vitals – ‘Pink slime’ panic grows online: Are we overreacting?.