Comparison of pinning to ageing

Summary

​Mechanical tenderisation (blade tenderisation, or ‘pinning’) is used to improve the tenderness and thus palatability of low value cuts, e.g. steaks from silverside, topside or knuckle. This project report describes an investigation of the effect of pinning on tenderness of selected whole muscles from each of these cuts, as determined by objective measurement of shear force; the effect of pinning on cooking losses; and the potential for microbial contamination on the surface of the muscle to be transferred to the deep tissues.
Outcomes
Peak shear force was measured to assess tenderness of muscles that had been subjected to pinning treatment together with a period of vacuum-pack, chilled ageing for up to a period of 21 days. The findings were different for each of the muscles investigated. For Control, non-pinned muscles, M. semimenmbranosus showed a highly significant improvement in tenderness over the ageing period whereas M. rectus femoris was little changed by ageing. There was some evidence of improved tenderness with ageing of M. biceps femoris but the effect was not as clear as with M. semimembranosus.
Except for M. biceps femoris, the other muscles investigated did show an improvement in tenderness, but generally the magnitude was low compared with the effect of ageing.
Pinning did not significantly affect cooking losses when cooked at either 70 or 80°C.
It is evident from the PF-IY data that neither ageing nor pinning had any significant effect on the contribution of connective tissue to overall texture.
Microbiologically, pinning can and does transfer microorganisms from the surface of the primal to the deep tissue. The proportion transferred can range from zero to 63%, but on average it is around 3-5%. If pathogens were present on the surface of the primal, they would be expected to be present at very low levels, so the numbers migrating into deep tissue would be very low. Thus, a USDA risk assessment concluded that the risk of illness from blade tenderised meat is only marginally greater than the risk of illness from non-blade tenderised meat.