[US] Everything you never wanted to know about meat
- The Washington Post - Wednesday, May 1, 2002; Page F01
Meats Meet Machine
By Robert L. Wolke
One day at the store, I picked up a package of chicken franks. The first
ingredient listed was "mechanically separated chicken." I started looking
at other prepared meat products and found "mechanically separated" beef and
pork. This brought up a number of questions:
1. What is mechanically separated meat?
2. What is the meat mechanically separated from?
3. What kinds of machines are used?
4. What is the difference between mechanically separated meat and, say,
hand-separated meat? And most important . . .
5. Why is mechanically separated meat specifically listed on the label?
The first time I saw those words on a label I said to myself, "What did you
expect? Did you think the meat we buy is cut by blood-splattered workers in
unsanitary slaughterhouses, slashing meat off the carcasses much as our
prehistoric ancestors did?" (I hate it when I talk to myself
disrespectfully like that.)
Terrible truth be told, yes; that's the way it's often done. But that's
another story. These days, machines supplement those workers by separating
the meat more efficiently from the bone or, more accurately, removing the
bones from the meat. (That answers your question No. 2.)
After the animal is killed and its blood drained out (procedures that the
meat industry delicately refers to as "immobilization" and
"exsanguination"), what had previously been skeletal muscle, that is,
muscle attached to the skeleton rather than muscular parts of the
circulatory system, has officially become meat. But the carcass is not all
meat; it contains internal organs, bones, cartilage, tendons, ligaments,
fat and skin, all of which need to be excised during the subsequent stage
of what might be called deconstruction.
In many cases, machines can remove more meat from the bones than even the
most skillful workers with knives can. But they can't produce whole cuts of
meat, as humans with saws and knives do; they produce meat either as small
trimmings or in a paste form. (That answers question No. 4.)
There are two general types of meat-removing machines, depending on whether
the bones are first crushed: Advanced Meat Recovery (AMR) systems and
Mechanically Separated Meat (MSM) systems.
In AMR machines, the meat is scraped or shaved off the bones in small
pieces. The USDA allows it to be labeled with words such as "beef
trimmings," "ground pork" and the like. But if it contains more than 150
milligrams of bone calcium per 100 grams of product, it must be labeled
In MSM machines, the bones are first crushed, after which the soft tissues
(muscle and fat) are forced through a sieve, separating them from bones,
cartilage, ligaments and tendons. (Answer to question No. 3.) What comes
out looks like fibrous ground meat. That's "Mechanically Separated Meat"
(answer to question No. 1), and the USDA requires that it be labeled as
such (answer to question No. 5).
The mechanical separation process is used mostly for poultry and fish
because their bones, when crushed, don't shatter into small fragments that
might pass through the sieve. Mechanically Separated Meat is nearly
boneless, but it may contain bone particles the size of table salt grains
and, so for better or for worse, is high in calcium, as you can see in any
product label's Nutrition Facts chart. In the case of beef or pork,
Mechanically Separated Meat is limited by the USDA to 20 percent in hot
dogs and bologna.
And while you're peering into the meat case, you may also see hot dogs
labeled as containing "Variety Meats." This is a euphemism for any or all
of the following: brains, hearts, large intestines (chitterlings), kidneys,
livers, spleens (melts), pancreas and thymus glands (sweetbreads), lips and
Other parts of animals that may find their way into hot dogs, sausages and
other mystery meats are blood, marrow, cheeks and other head trimmings,
feet (trotters), tails (oxtails), stomachs (hog maw), lungs (lights), small
intestines (sausage casings), skins (pork rinds), stomach linings (tripe),
and testicles (fries, prairie oysters or mountain oysters).
Robert L. Wolke (www.professorscience.com) is professor emeritus of
chemistry at the University of Pittsburgh and the author of "What Einstein
Told His Barber: More Scientific Answers to Everyday Questions" (Dell,
$12.95). His latest book is "What Einstein Told His Cook: Kitchen Science
Explained" (W.W. Norton, hard cover, $25.95). Send your questions to
© 2002 The Washington Post Company