Characterization of rigor mortis of longissimus dorsi and triceps brachii muscles of male cattle carcasses

Abstract

In this work, six bovine carcasses butchered in a slaughterhouse in Rio de Janeiro State, Brazil (SIE 504) were studied and temperature, pH, sarcomere length in different periods after slaughter (1, 5, 8, 12, 15 and
24 h) of the longissimus dorsi (LD) and triceps brachii (TB) muscles as well as the shear force (meat tenderness) and colour were evaluated, aiming at characterizing the rigor mortis in the meat during industrial processing. Data statistic treatment demonstrated that carcass temperature and pH decreased gradually during the industrial chilling. The chilly room temperature varied from 10.2 to 4.0°C, the mean initial temperature of longissimus dorsi was 34.03°C and the final one was 7.12°C; the mean initial temperature of Triceps brachii was 39.00°C and the final one was 6.42°C. The mean initial pH of Longissimus dorsi was 6.47 and the final one was 5.46; the mean initial pH of Triceps brachii was 6.66 and the final one was 5.54. The smallest sarcomere size obtained in both muscles occurred at 12 h post mortem, and the sarcomere lengths were 1.44 and 1.41 μm, respectively. As for the colour parameters, the b^* value presented higher correlation with the ultimate pH. The absence of cold shortening and the non-occurrence of dark firm and dry (DFD) meat indicate better quality of the meat analyzed.

Keywords: Bovine carcass, muscles, rigor mortis