Delayed carcass chilling improves tenderness of the beef gluteus medius muscle

The objective of this work was to evaluate the effects of a slower chilling rate on the physical traits of 14-day aged top sirloin (gluteus medius) from F1 Angus x Nellore young bulls. Slight and lean beef carcasses (n = 30) were split in half and selected for control (2 degrees C for 24 hours) and treatment (10 degrees C for 10 hours followed by 2 degrees C for 14 hours). Carcass temperature and pH decline were monitored in the longissimus dorsi (LD). Sarcomere length, color, and instrumental tenderness (Warner-Bratzler shear force and Volodkevich bite jaws) were measured on the gluteus medius (GM). pH 6.0 was reached when the LD temperature was very low, 3 degrees C for the control and 6 degrees C for the treatment. Differences in color and cooking losses were not significant. A trend was noticed for shorter sarcomere length and greater Warner-Bratzler shear force in the GM control. However, a lower value for Volodkcvich bite jaws was found in the GM subjected to the treatment. The cooling regimes adopted were not sufficiently different to cause changes in color traits; however, the slow chilling of carcass improved tenderness and can be a good alternative to produce high-value cuts.