Understanding the quality of typical and atypical dark cutting beef from heifers and steers

Dark cutting beef with pH < 6.0 may have glucidic potential approaching that of normal beef but has increased toughness that may also be influenced by cattle sex and carcass characteristics. Beef longissimus thoracis (LT) from normal (Canada AA; n = 24), and typical (TB4; pH > 5.9, n = 20) and atypical (AB4; pH < 5.9, n = 20) dark cutting carcasses were analyzed to investigate relationships between beef quality, pH, glucidic potential and carcass characteristics. Results indicated that reduced lactate and glucidic potential were accompanied by increased pH and reduced L*, a* and b* values. Mean glucidic potential was lowest (P < 0.0001) for TB4 whereas glucidic potentials for heifers and steers AB4 LT were sufficient to attain normal pH, substantiating the existence of atypical dark cutting. Warner-Bratzler shear force of AB4 remained higher (P < 0.05) than that of Canada AA LT confirming AB4 as the toughest beef irrespective of sex and carcass characteristics.