Hattix

Colloquially it’s a saying about sausages and law: Those who like it shouldn’t know how it’s made. It applies to a lot more foods too. This post is going to talk about mechanically recovered meat and meat reforming.

Nutritionally it’s near identical to any standard cut of meat, so there’s no health issue to worry about over what would be normal. What’s more fun is how it’s made and what it is.

We all have exposure to MRM and reformed meat, it’s what makes up those pre-sliced ham packets you can get anywhere. Mechanical recovery and reformation are two different processes and need not occur together (but MRM is almost always reformed, while reformed meat is not always MRM).

The particular example I’m using is a pack of ham slices I have here - “Thinly Sliced Ham”:
Pork (78%), Water, Salt, Dextrose, Stabilisers (E451, E450), Antioxidant (E301), Preservatives (E252, E250).

To the untrained eye, it looked as though it was just a slice through a block of ham. It’s not. It’s never been. After butchering and carving, a carcass typically has quite a bit of red meat (by ‘meat’ I’m refering to muscle, not offal or other forms of meat, but actual red meat which would otherwise be called ‘pork’) left on it. Some clings to the bones, other chunks are unattractive due to size or position. This is removed by forcing the bones through a mesh of fine metal wires. The result is cartilage, some meat and a few chips of bone. That’s mechanical recovery.

These slivers of meat are partly digested by the addition of enzymes to make them sticky, then forced into a block, which is reforming. The origin is usually quite a few animals from multiple sources. The block is forced together in a compression chamber where square blocks of sticky meat come out one side and a vaguely pink/white slurry sloshes in the other side. Tasty.

They then cure it and steam it before slicing and packaging.

78% pork, though? Most of the other 22% is water. A very light brine is added for three reasons. Firstly because reformed meat is very dry and would stick together in the pack and secondly because people consider meat that’s cold and wet to be fresher than meat that’s cold and dry. Finally and greatest of all is that it bulks out the meat. Sold by weight and 22% of the weight is water.

The salt added is part of the water and usually quite light as far as brine goes. The salt is added for very simple reasons: The reforming process removes salt from the pork which is naturally quite salty and salt is a preservative.

Dextrose is very simply, sugar. Or, rather, glucose, the most basic sugar. “Glucose” itself refers to D-glucose, it is a chiral compound with four chiral centers (centers with reflective symmetry but no superimposition symmetry or rotational symmetry - they make differently structured molecules) in the molecule, giving 16 enantiomers. Eight of them are biologically inactive in that they don’t taste sweet, they provide no energy to the body but are otherwise chemically identical, these are L-glucose and very hard to come by since no biological processes make them. Dextrose always refers to D-glucose. It’s added for taste.

E451 is sodium tripolyphosphate and potassium tripolyphosphate (Na₅P₃O₁₀ and K₅P₃O₁₀) which are used as emulsifiers, preservatives, acidity regulators but overwhelmingly (and especially here) as hydrolysers or emulsifiers - They make food retain water. It adds a rather soapy taste so is used sparingly. Used here it is an emulsifier, but it’s also used in detergents (it softens hard water), toothpaste and industry. While not toxic or harmful in any testing, most juristictions limit how much tripolyphosphate can be added because of its bulking properties, it makes protein-based food (meat, seafood, etc.) take on water so make them heavier. When buying by weight, this adds to the sale price but not to the production cost. In our 22% water ham, it’s there to keep the water in the ham.

E450 is similar to E451, but is E450(i) Disodium diphosphate, E450 (ii) Trisodium diphosphate, E450 (iii) Tetrasodium pyrophosphate, E450 (v) Tetrapotassium pyrophosphate, E450 (vi) Calcium dihydrogen diphosphate. These are a group of diphosphates. For some of them the older “pyrophosphate” name is more common, but they are all actually diphosphate. Diphosphate is extremely important in biology as it is part of the respiration process whereby sugars and fats are metabolised to energy. As a pure chemical, it is slightly toxic and mildly irritant and can cause an allergic reaction to sensitive people when used in food. In food it is used as a buffering agent (resists changes in acidity), an emulsifier as E451 is and as a thickening agent. Here it is an emulsifier…why two? E451 can be quite unpleasantly tasting but E450 is tasteless. It’s added in much larger quantities to soy-based meat ‘alternatives’ which aren’t terribly healthy to begin with.

E301 is the sodium salt of ascorbic acid, vitamin C. It’s used here as an antioxidant, specifically to prevent the formation of nitrosamines from nitrites via contact with oxygen.

E252 is potassium nitrate or saltpetre/saltpeter. It is used as an explosive, a fertiliser and a food additive and has been used for curing meat for hundreds of years. Traditional foods have used potassium nitrate to preserve meat long before the chemical was even known about, usually as ashes from burnt wood.

E250 is why E301 is present, sodium or potassium nitrite. They are antibacterial and antifungal compounds used largely to prevent the occurence of clostridium botulinum (botulism). Nitrites oxidise to nitrosamines which are listed as being potentially carcinogenic, but unproven. Nitrosamines are formed from nitrites and some amino acids (e.g. vitamins, proteins) under high temperatures (frying), acidic environments (e.g. your stomach) and in the presence of oxygen (e.g. in air). Since we can’t get amino acids, the “building blocks” of life, any way other than by eating them then nitrosamines are produced by the body during digestion, mostly from meat. Some studies have linked them to cancers of the gastric tract and oesophagus but at a very low risk. The conversion rate from nitrites isn’t great in the stomach (not hot enough) so risk is very low if anything.