This study investigated the effect of fresh beef tumbling and postmortem ageing on the quality and proteolysis of loins from cull cows. Loins (M. longissimus lumborum) from twelve carcasses (Holstein breed, fat utility, >30 months) were obtained at 5d postmortem, sectioned, and assigned to three treatments (NT, T: tumbled, and TS: tumbled with spike mat). The beef sections were cut into halves and assigned to ageing treatments (0d or 14d). No significant tumbling impacts were found on instrumental tenderness, proteolysis (desmin and troponin-T degradation and myofibrillar fragmentation) of cull cow beef loins. Tumbling did not affect the initial purge, drip or thaw loss of beef samples (P > 0.05), while TS induced higher moisture losses compared with NT (P < 0.05). Significant interactions between tumbling and ageing treatments were found, where consumer panel determined higher tenderness liking and overall liking of tumbled beef loins (T and TS) compared to NT without further ageing. However, after additional 2 weeks of ageing, no differences between treatments were observed in those sensory attributes (P > 0.05). These results indicate that fresh beef tumbling could be an effective, simple and natural method to improve tenderness of cull cow beef loins.
