Comportamento mecanico e estrutural de diferentes cortes carneos em teste de determinacao da forca de cisalhamento/Mechanical and structural behaviours of different meat muscles in shear strength test

This research evaluated the mechanical and structural behaviours of different meat cuts in shear force tests with the aim of identifying possible differences that could negatively influence objective tenderness measurements. Five Brazilian beef cuts (Longissimus dorsi, Tensor fasciae latae, Semitendinosus, Psoas major and Biceps femoris) and Pork loin (Longissimus dorsi)) were analyzed according to the Warner-Bratzler method using a texturometer equipped with a 1 mm thick blade. The sheared surfaces were analyzed by scanning electron microscopy and the mechanical curves generated during the tests were studied. Different behaviours were observed in the mechanical curves and in the microstructure of the meat cuts studied. Some muscles showed well defined maximum peaks while others showed wider curves with greater distribution of the force during testing. The muscles also varied with respect to peak heights between different muscles and even within the same muscle. Different behaviours were observed in the microstructure, such as fibers deformed by the tensile strength, agglomerated fibers due to the great compression and irregularities in fiber thickness and shape. Thus, it was concluded that the shear force test used involved other mechanical principles such as compression and elongation, depending on the meat cut studied.