Tenderness and Color Stability of Beef Longissimus Thoracis and Semimembranosus Steaks From Carcasses With Varying Hot Carcass Weights

Abstract

Our objectives were to determine how beef hot carcass weights relate to temperature and pH decline, Warner-Bratzler shear force, and objective color of steaks from the longissimus thoracis and semimembranosus. Beef carcasses (N = 59) were selected at a commercial plant based on hot carcass weight and separated into either light- (< 363 kg), medium- (364–407 kg), or heavy-weight (> 408 kg) groups. Temperature and pH in the longissimus thoracis and semi-membranosus muscle were measured for 24 h. After carcasses were chilled for approximately 24 h, ribeye area, 12th rib backfat, kidney, pelvic, and heart fat percentage, marbling score, and USDA final yield grade were collected. Ribeye rolls (Institutional Meat Purchase Specification 112a) and inside rounds (Institutional Meat Purchase Specification 160a) were collected at the plant and transported to the North Dakota State University Meat Laboratory. Data were analyzed using the mixed procedure of SAS version 9.4 (SAS Institute Inc., Cary, NC) with carcass weight class as the fixed effect and day of collection as random. Longissimus thoracis muscle temperature of light-weight carcasses was lower at 4 h compared with heavy-weight carcasses (P = 0.02). Semimembranosus muscle temperature of light- and medium-weight carcasses was lower at 24 h compared with heavy-weight carcasses (P < 0.0001). There were no differences in pH decline (P ≥ 0.16) among carcass weight groups. There were no differences in fat thickness; kidney, pelvic, and heart fat percentage; or marbling score (P ≥ 0.12) among carcass groups. There were no differences in drip loss, cook loss, or Warner-Bratzler shear force in either longissimus thoracis or semimembranosus muscles (P ≥ 0.10) among carcass groups. Objective color measurements found that steaks from heavy-weight carcasses were redder than steaks from light-weight carcasses (P ≤ 0.02). Hot carcass weight group did not influence most meat quality attributes of steaks with the possible exception of color.