Primal Block and Extended Ageing Sensory Analysis

Summary

​Post mortem cut ageing is an important part of the Meat Standards Australia Australia (MSA) prediction model however presents challenges in relation to developing precise estimates due to the interactions with factors such as; animal genetics, muscle calpastatin levels, HGP use, pH and temperature during ageing which are all likely to impact the ageing process.
Current MSA data is extremely limited for cuts aged beyond 35 days. Given the increased volume of Australian beef brands, underpinned by MSA entering export markets, it was viewed that additional ageing data would be of value, in particular relating to muscle ageing at extended days. Related areas of interest were the potential effects of temperature variation and of ageing in a primal form versus ageing as a prepared steak.
This study was undertaken as an additional opportunistic component of a larger trial designed to study potential stress effects on eating quality, utilising 5 muscles at 7 and 21 days ageing. Additional samples were prepared from the same primals and aged for 21 or 42 days in a "block" form, thus simulating primal ageing prior to being fabricated as 5 individual small steaks, as per standard MSA protocol, and frozen. A second set of samples were prepared to standard MSA protocols and subjected to variable temperatures during storage, loosely representative of a domestic butcher shop environment, to evaluate the potential need to differentiate ageing estimates for domestic and export meat.
The base study 21 day aged samples provided a control for comparison to the alternative treatments. Further samples aged beyond 21 days were also prepared and are to be analysed in conjunction with the new 2017 MSA model development. Analysis found no statistically significant difference between the standard MSA ageing protocol to 21 days as a primal "block" versus a prepared steak "slice" and also no impact on ageing from the applied temperature variation.
It should be noted that this was not a shelf life study and that from other studies temperature variation is considered likely to result in reduced shelf life. While the current study is of limited size, the MSA Beef Pathways Committee concluded that the standard MSA preparation protocol adequately relates to beef aged as vacuum-packed primals and that common model ageing estimates can be adopted for export and domestic meat to 21 days.