Volume 13: Industry Processes and Controls
4. Mechanically recovered meat (MRM)
Processes for mechanical recovery of meat in 1986
Bones for processing
Recovery of meat
Vertebral column and spinal cord
Bovine heads

Bones for processing

4.15 The carcass bones from which MRM was recovered were already stripped of most meat before the process began. Furthermore, MRM was not derived from all the bones of cattle carcasses. Usually only the vertebrae, ribs, shoulder blade and the pelvis were used. ¹

4.16 MRM could be recovered from both cooked and uncooked bones. ² As discussed below, the machines squeezed the remaining meat as well as certain components from the bones during processing. Long bones, with high marrow content, were considered unsuitable because of the high concentration of calcium, iron and purines in the marrow. ³

4.17 The BMMA Code of Practice required that the bones from which meat was to be recovered be refrigerated and that the meat be recovered within a specified period. For instance, uncooked bones generally had to be chilled to 7°C or below and the meat removed within 96 hours of slaughter. ⁴

Recovery of meat

4.18 The machines used to recover the residual meat varied in design and action. ⁵ Many used a piston to subject bones to very high pressure in order to extract the flesh from them. They then forced the resultant slurry out through a series of sieves that filtered out any large particles. Any connective tissue or collagen was also removed at this point, being a by-product of the process. ⁶ Mr Peter Soul of the MHS described the process for the Inquiry:

The machine was basically a device that put the bones under high pressure and squeezed the MRM through a sieve leaving behind bone pulp which was then ejected. Vertebral columns could go through MRM machines in the same way as any other bones other than the head. ⁷

4.19 It is apparent that the different mechanical methods applied produced different results:

There are a number of different machines which put the bones under pressure to a greater or lesser extent and produce more of a slurry or less of a slurry. ⁸

4.20 The end product of the process did not resemble 'meat' in the traditional sense. Rather, as Mr Wildman of Sainsbury's supermarkets explained, it is 'more of a slurry than a recognised piece of meat'. ⁹ It has also been described as a 'puréed mixture of meat and bone marrow'. ¹⁰ Although research found that MRM contained comparatively higher levels of calcium, iron and total purines and lower levels of nitrogen and connective tissue, its gross composition did not differ significantly or consistently from meat deboned by hand. ¹¹

Vertebral column and spinal cord

4.21 The vertebral column, together with the ribs, was the major source of bovine MRM. Because of the difficulty of deboning it by hand, the vertebral column - 'an intricate collection of bones' ¹² - was the part of the skeleton which had the most commercially attractive amount of meat still attached. ¹³

4.22 Parts of the spinal cords were also inadvertently incorporated into MRM when processing the vertebral column:

The carcass is normally split using a circular saw and this shatters the spinal cord, and the sides of beef, after being boned out, have the residual bone treated hydraulically to produce re-claimed meat that will include spinal cord pieces, etc. This meat is used in all types of convenience foods. ¹⁴

4.23 The Inquiry also heard from Mr Keith Baker, Assistant Chief Veterinary Officer, who agreed that if pieces of spinal cord were left on the carcass, their most likely destination was MRM. ¹⁵

4.24 A report prepared for MAFF in 1997 endeavoured to audit the supply of bovine products to humans and animals between 1980 and 1995. It found that at least one major MRM producer regularly removed spinal cord 'for quality reasons', 'although it was admitted that this had been done more thoroughly after the 1989 SBO ban'. Another MRM manufacturer said that although spinal cord was generally removed before recovery of MRM, prior to 1989 one-quarter of the vertebral columns it processed would have had part of the spinal cord attached. Based on such information, the report estimated the possible extent of contamination of beef MRM with spinal cord prior to the SBO controls:

The average contamination of beef MRM with spinal cord would therefore be ca 0.04%. However, there would be likely to be considerable variation about this figure; the worst-case (where all of the vertebral columns contained an intact spinal cord) would give ca 2.8% contamination. A 100g meat product, containing 10% of such beef MRM, would contain 0.28g spinal cord. ¹⁶

Bovine heads

4.25 The BMMA Code of Practice required that the head be excluded from the MRM recovery process. ¹⁷ It was noted in 1990 by MAFF that there was 'no evidence to suggest that heads are used for the production of MRM'. ¹⁸ This was confirmed subsequently by the MLC following consultation with the MRM industry. ¹⁹

4.26 Although a representative of the Chartered Institute of Environmental Health (CIEH) suggested that heads were used in the MRM process, the weight of evidence was against this proposition. ²⁰ The exclusion of heads was confirmed in evidence provided to the Inquiry by Mr Keith Baker, Mr Christopher Clark of the MHS, Mr Ray Bradley of MAFF's Central Veterinary Laboratory and Mr Colin Maclean of the MLC. ²¹ Mr Soul also said that heads were never included 'because the enamel of the teeth was such as to damage the machine'. ²²