Assessment of caspase activity in post mortem muscle as a way to explain characteristics of DFD beef

Pre-slaughter stress can lead to ‘dark cutting’ defective meat characterized by a high ultimate pH (pHu) in cattle, causing high economical losses in the meat industry. Therefore, the study of biochemical mechanisms related to animal stress response is a fact that needs to be addressed. The aim of this work was to determine caspase 9 and 3/7 activities in high and normal pHu muscle samples at 24 h post mortem as a way to reveal stress situations in different Spanish local breeds (Asturiana de los Valles, Retinta and Rubia Gallega) and crossbred animals (n = 83). Either breed or pHu factors had an effect in both caspase activities, showing the high pHu group the highest caspase activity independently of the studied breed. In contrast, activity levels among breeds were slightly different for each caspase and between the high and normal pHu group in the case of caspase 3/7. Overall, this study demonstrated that caspase activity can be a good indicator to detect stress situations that might lead to defective high pHu meats.