Characterization of rigor mortis process of muscles lamb of Santa Inês breed and F1 Santa Inês x Dorper

Abstract

The development of rigor mortis process of butcher animal carcasses directly influencing the meat quality. The characteristics of rigor mortis process in ovine carcass during industrial chilling to obtain the chilled carcasses have been studied in other countries and in Brazil in Santa Ines sheep, but not yet established in F1 Dorper x Santa Inês. Thus, this research was designed to characterize the rigor mortis process of Semitendinosus and Triceps brachii muscles during the industrial chilling and meat tenderness in 10 ovine carcasses. Ten intact male ovines breed were randomly assembled, six of Santa Inês breed and four F1 Dorper x Santa Inês, slaughtered at Campos Slaughterhouse – Campos dos Goytacazes, Rio de Janeiro. After exsanguination, were measured temperature, pH and sarcomere length at different times (4h; 6h; 8h; 10h; 12h; and 24h) and shear force or tenderness (48h) of Semitendinosus muscle. In parallel was accomplished the sensorial analysis relationships to instrumental values of this muscle. The chilling room temperature varied between 12.2 °C (4h) and -0.5°C (24h) and the mean temperature of carcasses was 26.80°C and -0.20°C, respectively. The mean initial pH of Semitendinosus was 6.62 and final 5.64 and of Triceps brachii was 6.50 (4h) and 5.68 (24h). The maximum contraction of sarcomere of Semitendinosus occurred at 12^th hour (1.50mm) after exsanguination whereas for the Triceps brachii,at the range of the 10^th to 24^th hours (1.53 to 1.57mm). Semitendinosus muscle shear force and tenderness was similar in lambs of Santa Ines breed and F1 Dorper x Santa Inês, demonstrating that the genetic group did not affect meat tenderness. The sensory panel confirmed the results obtained in instrumental analysis. The correlation of instrumental analysis (shear force) when compared different genetic groups, was found a good inversed correlation (r = -0.87).