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

Abstract

Summary Ultimate pH (pH u ) 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‐pH u (≤5.79), Intermediate‐pH u (5.80–6.29) and High‐pH u (≥6.30) groups, portioned into steaks, vacuum packaged and matured at 2 °C for 0, 7, 14, 21 and 28 days. High‐pH u steaks exhibited impaired colour stability and were darker compared to the other groups. High‐ and Normal‐pH u steaks showed improved tenderness and myofibrillar fragmentation linked to proteolysis. Intermediate‐pH u steaks were associated with a lower meat tenderness and decreased collagen solubility. High‐pH u steaks retained a high pH during ageing and increased water‐holding capacity. These findings provide evidence that highlight pH u as a strategy for the classification of pH u ‐dependent beef quality from Nellore bulls that can be adopted by the Brazilian meat industry.