Mechanically separated meat

Mechanically separated meat (MSM), mechanically recovered/reclaimed meat (MRM), or mechanically deboned meat (MDM) is a paste-like meat product produced by forcing pureed or ground beef, pork, turkey or chicken, under high pressure through a sieve or similar device to separate the bone from the edible meat tissue. It is sometimes called "white slime" as an analog to meat-additive pink slime and to meat extracted by advanced meat recovery systems, both of which are different processes. The process entails pureeing or grinding the carcass left after the manual removal of meat from the bones and then forcing the slurry through a sieve under pressure. This puree includes bone, bone marrow, skin, nerves, blood vessels, and the scraps of meat remaining on the bones. The resulting product is a blend primarily consisting of tissues not generally considered meat along with a much smaller amount of actual meat (muscle tissue). In some countries such as the United States, these non-meat materials are processed separately for human and non-human uses and consumption. The process is controversial; Forbes, for example, called it a "not-so-appetizing meat production process".

Mechanically separated meat has been used in certain meat and meat products, such as hot dogs and bologna sausage, since the late 1960s. However, not all such meat products are manufactured using an MSM process. In fact, many are not, particularly in the U.S. For the production of chicken and turkey MSM, most of the time, breast carcasses are used as they still contain parts of breast meat.

The practice of mechanically harvesting leftover meat scraps dates to the 1950s, when mechanical hand tools were developed to help remove the remaining pieces of meat and connective tissue from animal carcasses to minimize waste, although said tissues were not automatically or necessarily "wasted" when used for other purposes. Primarily MSM was developed in and produced in countries with agriculture industries insufficiently productive to provide mass quantities of regularly processed meat for widespread and affordable consumption. By the 1960s, machines that did this more efficiently, and automatically, were developed. This allowed companies to use previously wasted materials and, in turn, sell the derived meat products to the public for a lower price. During the 1970s, these techniques became more common in other parts of the world, as well. In addition to poultry slaughterhouses, newcomers entered the market as they recognized the financial gains that mechanically separated meat processing allowed. Eastern European countries, especially, are known for their import of frozen chicken MSM.

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Wikipedia