Meat tenderness is positively associated with connective tissue solubilization, sarcoplasmic proteins aggregation and collagenolytic activity, while denaturation of myofibrillar proteins and great water losses contribute to meat toughening (Baldwin, 2012). Roldán et al. (2013) have associated the decrease in hardness and shear force with the time of sous vide cooking to a greater collagen solubilization and no further increase of myofibrillar shrinkage at longer times. According to this, in the present study, changes in the percentage of hydrolysed collagen among samples sous vide cooked during 2, 4, 6 and 8 h correlated negatively to firmness, toughness and hardness. However, 1 h cooked samples do not follow this trend, and obtained the lowest values for these instrumental texture parameters and for hydrolysed collagen and cooking loss. Tornberg (2005) pointed out that the low stress needed to compress raw meat is due to the viscous flow in the fluid-filled channels in between fibres and fibre bundles. A similar behaviour may occur in the 1 h sous vide cooked samples of this study, since they have experimented a slighter cooking loss than the samples cooked during longer times.