Aged Meat for Mincing Review

Overall, the review undertaken by Bristol University has found little scientific data to support the current restrictions on the age of the meat used to make minced meat. The main points to emerge are that:

1. No clear scientific literature has been located to support the restrictions on the time between slaughter and production of minced meat. Thus, there appears to be no scientific justification for the time restrictions included in the current legislation.

2. No specific scientific publications have been located that look at the safety and quality of mince produced from cuts and carcasses that have been stored for different periods of time post-slaughter.

3. No publications have been located that show that the safety (i.e. pathogen survival) of mince produced from older meat is compromised, or visa versa.

4. There is a surprising lack of data on the storage-life of chilled meat carcasses and bone-in-cuts. The classic studies indicate much shorter storage lives than current industrial practice as indicated in IIR tables etc.

5. As would be expected, the data that does exist shows that initial bacterial numbers, storage atmosphere and temperature are the main factors governing storage life. Other factors influencing storage life are pH and RH and the rate of initial chilling.

6. Overall, data on the growth of psychrotrophic pathogens would indicate that there is theoretically a greater risk of psychrotrophic pathogens L. monocytogenes and Y. enterocolitica and to a lesser extent E. coli H157:H7, B. cereus, non-proteolytic Cl. botulinum proliferating in meat held for a longer time at a temperature above the minimum for pathogenic growth than in meat stored for a short time.

7. From the literature it is uncertain how much, if any, additional risk ageing presents. Some authors (Dykes et al., 2001) imply that that the long period of storage, of particularly E. coli O157, in a non-growing state would result in “an excessive recovery period in these cells before growth would occur”. The inhibitory interaction of the background microflora also needs to be taken into account.

8. It is clear that further research would be beneficial to address the data gaps identified by the review and so determine, within procedures based on HACCP principles, what controls, if any, should be placed on meat prior to mincing. This requirement has been advertised by the Food Standards Agency and research is expected to commence spring 2008.