Interventions of two-stage thermal sous-vide cooking on the toughness of beef semitendinosus

This paper describes the influence of different factors on toughness of beef semitendinosus (ST) by means of low temperature-long time cooking with single-stage (60 degrees C, 65 degrees C, 70 degrees C, and 75 degrees C for 6 h and 12 h) and two-stage sous-vide procedure (45 + 60 degrees C, 45 + 65 degrees C, 45 + 70 degrees C, and 45 + 75 degrees C; 49 + 60 degrees C, 49 + 65 degrees C, 49 + 70 degrees C, and 49 + 75 degrees C for 3 h at the first temperature, and either 3 or 9 h at the second temperature). Reduced toughness of ST beef steak muscle could be attained in 6 h at 60 degrees C and 45 + 60 degrees C were due from the minimum shrinkage of sarcomere as well as lower perimysial thickness, cooking loss, and elastic modulus. Collagen solubility showed a positive correlation to the toughness values. The relationship between proteolytic activity and shear force can be seen after 12 h of cooking duration. For the other quality attributes, two stepped cooking temperature-time combination seems to be more effective in preserving the redness values and water content than a single-stage sous-vide method.