Relationship between heifer carcass maturity and beef quality characteristics

Our objective was to determine the relationship between heifer carcass maturity and beef palatability of the longissimus lumborum (LM) and biceps femoris (BF). Left sides of A (n = 30), B (n = 30), and C (n = 30) maturity heifer carcasses under 30 mo of age by dentition were used. Carcasses were selected to ensure similar marbling scores across maturity groups (Small to Modest). Beef strip loins (LM) and outside rounds (BF) were obtained from these carcasses. Steaks were used to measure color stability, lipid oxidation (thiobarbituric acid reactive substances; TBARS), Warner-Bratzler shear force (WBSF), soluble and insoluble collagen, and consumer sensory perceptions. Heifer carcass maturity did not affect pH, fluid loss, WBSF, or collagen content of LM or BF steaks (P > 0.29). In LM and BF steaks, a maturity × day of retail display interaction occurred for TBARS, in which B maturity steaks had lower levels of lipid oxidation compared with A and C maturity steaks from the fourth day to the end of the retail display (P < 0.01). Nevertheless, LM steaks from B maturity carcasses tended to have lower overall acceptability (P = 0.08) and juiciness (P = 0.09) than steaks from C maturity carcasses, but steaks from B and C maturity carcasses did not differ from LM steaks obtained from A maturity carcasses. No differences in tenderness or flavor were observed due to maturity (P > 0.24). Similarly, maturity had no effect on sensory characteristics of BF steaks (P > 0.30). In conclusion, our results indicate that advanced physiological maturity does not decrease palatability of strip loin or outside round steaks from carcasses of heifers under 30 mo of age.