As far as I can tell, "mechanically separated meat" is meat that's been mechanically separated from bones by a grinding process. The prion fears are because som

As far as I can tell, "mechanically separated meat" is meat that's been mechanically separated from bones by a grinding process. The prion fears are because some of the bone gets in, and some of the bone contains nerve tissue. The article says that pink slime is instead made from beef trimmings, which does not involve that grinding process. https://en.wikipedia.org/wiki/Advanced_meat_recovery https://en.wikipedia.org/wiki/Advanced_meat_recovery > The meat produced in this manner can contain no more than 150(±30) milligrams of calcium per 200 grams product, as calcium in such high concentrations in the product would be indicative of bone being mixed with the meat. Products that exceed the calcium content limit must instead be labeled "mechanically separated beef or pork" in the ingredients statement.