Chilling Rates Impact Carcass and Meat Quality Parameters of Bos indicus Cattle

Abstract

This study evaluated the impact of chilling decline rates on carcass and meat quality parameters of Bos indicus cattle. Eighty Nellore bull carcass halves were used, allocated equally into 2 treatments: conventional and dynamic chilling environment. Temperature and pH were recorded at 0, 2, 4, 6, 12, and 24 h in the longissimus thoracis muscle. Cold carcass weight and meat samples were extracted 24 h post-slaughter. Cold carcass weight tended to be lower in the dynamic environment (P=0.096). Shrink percentage was higher in the conventional than in the dynamic chilling environment (P=0.049). The pH values were significantly higher in the dynamic chilling environment at 2, 4, 6, and 12 h after slaughter (P<0.022). Also, there was a tendency for high ultimate pH in the dynamic treatment (P=0.059). Temperature values were significantly lower in the dynamic treatment from 4 to 24 h postmortem (P<0.001) compared with the conventional treatment. Carcasses subjected to the conventional chilling rate presented higher temperatures at pH 6 (P<0.001), which was reached in a shorter period (P=0.024). Carcasses in the conventional treatment had a lower pH at the temperature of18°C than in the dynamic chilling environment (P<0.001). There were no differences in water losses and sarcomere length between chilling environments (P≥0.344). However, meat samples from the conventional chilling environment had higher mean values for color parameters a*, b*, oxymyoglobin, and chroma (P≤0.006) and a tendency for lower shear force (P=0.06). In contrast, the deoxymyoglobin value was higher in the dynamic than the conventional chilling treatment (P=0.002). The variation in chilling rate impacted mainly the decline in meat pH and meat color, with the dynamic chilling environment producing a less bright red color.