Influence of ultimate pH on biochemistry and quality of Longissimus lumborum steaks from Nellore bulls during ageing

Summary Ultimate pH (pHu) is an indicator that influences post‐mortem meat quality. We studied physiological and biochemical changes of steaks obtained from Nellore bulls (Bos indicus) during post‐mortem ageing. To this, Longissimus lumborum (LL) muscles were classified into three groups: Normal‐pHu (≤5.79), Intermediate‐pHu (5.80–6.29) and High‐pHu (≥6.30) groups, portioned into steaks, vacuum packaged and matured at 2 °C for 0, 7, 14, 21 and 28 days. High‐pHu steaks exhibited impaired colour stability and were darker compared to the other groups. High‐ and Normal‐pHu steaks showed improved tenderness and myofibrillar fragmentation linked to proteolysis. Intermediate‐pHu steaks were associated with a lower meat tenderness and decreased collagen solubility. High‐pHu steaks retained a high pH during ageing and increased water‐holding capacity. These findings provide evidence that highlight pHu as a strategy for the classification of pHu‐dependent beef quality from Nellore bulls that can be adopted by the Brazilian meat industry. Ultimate pH (pHu) is an indicator that influences post‐mortem meat quality. The rate and extent of post‐mortem pHu decline is directly influenced by several pre‐ and post‐slaughter factors. High‐ and Normal‐pHu steaks from Nellore bulls showed improved tenderness linked to proteolysis. In turn, intermediate‐pHu steaks were associated with a lower meat tenderness. The colour stability was impaired in High‐pHu steaks. Thus, the carcass segregation by the pHu can be a valid and suitable strategy for the classification of pHu‐dependent beef quality from Nellore bulls that can be adopted by the industry.