Is Mechanically Retrieved Meat (MRM) a Health Hazard?

In his campaign to improve the quality of food served to Britain's schoolchildren, chef Jamie Oliver graphically demonstrated what some food favourites are made of. Drop a chicken carcass into a blender and observe the resulting pink slurry.

Similar meat sludge goes into many products, including pies, hot dogs, sausages and foods made of re-formed meat, like some chicken nuggets and burgers. A recently-screened BBC programme on Britain's worst foods repeated the Oliver experiment. Shoppers gagged as meat remnants were pulverised into a taramasalata-like goo. But others who hadn't seen the demo ate sausages made from it and pronounced them tasty. Taste may not be a wholesomeness test - but is food unhealthy just because it's made of offcuts and, pre-makeover, looks ghastly?

Mechanical retrieval

As any cook knows, there's always meat left after carving, but removing the scraps is time-consuming. What are you going to do with it anyway, except treat the dog? For the meat industry this is profitable waste, even if only for pet food. But it's not economical to remove it by hand.

Carcasses are mechanically forced against a screen or sieve, with pressure applied to remove the residual meat. In principle, it sounds okay, but as well as meat, the bits retrieved include connective tissue (tendons and gristle), bone and, depending on which parts of the carcass are used, brain or spinal cord material.

Culinary fashions

When meat was a treat, perhaps only eaten bi-weekly, nothing was wasted. Modern sensibilities have seen many meat dishes fall into obscurity. Few of us have liver and kidneys on our shopping list, let alone brain and sweetbreads (thymus and pineal glands).

It wasn't long ago that menus featured pig's trotters, tongue and oxtail and any bones and remnants, from gizzards to chicken feet, went to simmer in the stockpot. Go back a few hundred years, to the times of Jane Austen, for example, and the menus are an eye-opening testament to changing tastes.

So what's the problem?

There is nothing intrinsically wrong with any part of a carcass, from eyes to testicles. Our revulsion is cultural; the way the meat is retrieved should be a side issue. In practice, there were problems. The inclusion of pulverized bone may give MRM a high calcium content, harmful in excessive quantities. More worrying is the small threat of Creutzfeldt-Jacob disease (CJD), which can potentially reside in brain and spinal cord BSE-infected cattle (bovine spongiform encephalitis, or 'mad cow' disease).

American and British food authorities addressed these problems, limiting the proportion of MRM permitted in products, ensuring non-contamination by neural tissue and regulating labeling. So-called 'advanced meat recovery' entails mechanical separation of meat from carcasses without breaking the bones.

Not quite an all-clear

MRM products are lower quality but not necessarily hazardous. However, the story doesn't end there. Processing takes time, during which meat goes off. Chemical preservatives with effects still poorly understood are added to stop oxidation and organisms multiplying. It seems logical that the cheaper the product, the more likely it is that other corners have been cut for profit. And is that pie's pastry made from hydrogenated fat? The processing turns it into trans fat - that's the saturated kind that causes heart disease...

References

Mechanically recovered meat. BSE Controls Final Report, 20 December 2000. Section 14www.food.gov.uk/bse/what/about/bsereport/rep14
Britain's Really Disgusting Foods. BBC3, 2008.
Jamie's School Dinners (DVD), Channel 4 Television 2005.
'What are hydrogenated fats and trans fats?' UK Food Standards Agency. http://www.eatwell.gov.uk/asksam/healthydiet/fssq/