| Popis: |
Beef carcass weights (HCW) and quality grades (QG) have increased in the United States the last 30 years, yet chilling systems have not drastically changed. The objective was to examine the influence of HCW and QG [USDA select, low choice (LC), upper 2/3 choice (UC), and prime)] on internal temperature decline of the chuck, loin, and round. Carcasses (n=309) were selected by weight [light (LW) = 295.5–341 kg; middle (MW) = 386.4–431.8 kg; heavy (HW) = 465.9–522.7 kg]. Data loggers were placed 20.32 cm deep in the chuck and round and 10.16 cm deep in the loin to record internal temperature for 26 h. Data were analyzed using the PROC MIXED procedure in SAS using HCW and QG as the main effects. A HCW×QG interaction was observed in the chuck (P=0.0286) and round (P< 0.0001), but not the loin (P=0.0689). Chuck temperatures from LC HW carcasses were 1.8°C higher at 0 h compared to LC LW, LC MW, and select MW carcasses (P< 0.05). At 26 h, all LW, select MW, and LC MW chucks had final temperatures at 6.1°C-7.7°C, followed by UC and prime MW at 9.1°C-9.5°C, then all HW chucks at 10.7°C-11.6°C (P< 0.05). At 0 h, select and prime LW rounds had lower temperatures compared to other rounds (P< 0.03). Round temperatures began to decline at 1.75 h in LW and 2.25 h in MW and HW carcasses. Final temperatures for LW and MW were 3.7-5.9⁰C and 1.6-3.0⁰C cooler, respectively, compared to HW rounds at 26 hr (P< 0.04). Loins started with similar temperatures (39.2-40.7⁰C; P >0.05). Elevated temperatures were observed in HW loins, compared to LW and MW loins (P< 0.05), until 26 h when similar temperatures were achieved (P >0.05). Carcass weight and quality grade interact during chilling and this relationship requires further research. |
