Experts weigh in on "mechanically separated chicken".
A practice the poultry industry has used since the 1960s to salvage tiny pieces of meat stuck to the frames of chickens is garnering new attention in the wake of the public furor over "pink slime".
If you check the label of some of your favorite foods like hot dogs, bologna and a lot of processed deli meats, you'll notice the term "mechanically separated chicken."
"It's been around for a long time," says Texas A&M Associate Professor Dr. Christine Alvarado. "It's a really efficient system and it does add a lot of meat supply into a lot of products that we use now."
Alvarado explained that processing plants remove the best cuts of meat from chicken carcasses first, the breasts, the legs and thighs.
There is still a lot of meat left on the frames that the plants couldn't retrieve with a knife.
To get to that meat, plants put the whole carcass into a machine that grinds it all up.
Then the mixture is poured or pushed through a sieve to separate the bigger bits of bone from the meat.
The end product is mechanically separated chicken.
"It's high-quality protein," said Alvarado. "It may not be in a form of a whole breast muscle that we're used to seeing, like parts in a grocery store, but it is just mainly white meat protein."
Sarah Klein, a nutrition consumer advocate with the Center for Science in the Public Interest, said it is mostly meat, but not completely.
"I think it is fair to say that there is pulverized bone, pulverized sinew, tendon, perhaps artery that finds its way into the finished product."
The United States Department of Agriculture's own regulations allow up to one percent of mechanically separated chicken to be bits of bone up to two millimeters in size and less than a quarter of one percent to be calcium content or ground bone.
"If a consumer wouldn't eat this on their plate as part of a meal, should we really be including it in their food as a hidden ingredient?" asked Klein.
Unlike lean, finely textured beef, also known as "pink slime," mechanically separated chicken does have to be included in any products list of ingredients.
Klein said the labeling requirements do no good when the products are served in schools and hospitals where customers rarely see a label.
"That's the important thing is that consumers need to be able to weigh in on these processes and not just have them done by the food industry and have them hidden under the rug," said Klein.
People might be thinking that nuggets formed into the shape of dinosaurs or crowns must be made with mechanically separated chicken because those shapes don't exist in nature, but some manufacturers mince chicken meat so that they can form it into nuggets or other shapes kids will like.
The best way to know if mechanically separated chicken is in a product is to read the label.
The beef industry used to produce mechanically separated beef with cow carcasses, but the USDA banned the process for beef in 2004 because it worried that spinal tissue that carries mad cow disease could get mixed into the meat.
Mechanically separated poultry and pork are still allowed.
The USDA says they are perfectly safe.