MEAT AGING MEASUREMENT - COMPARISON BETWE EN 2 MECHANICAL METHODS

The resistance of myofibrillar structure to a 0.2 strain was measured during ageing with two compressive methods on raw meat samples from ol d cows Longissimus Dorsi muscles. One measurement used a 10 Hz sinusoi dal compression cycle performed on the Systeme d'Analyse de 1a Texture des Aliments. The other measurement used a classical linear compressi on system, with a probe speed of 50 mm/min. There was a close linear r elationship (r = 0.96, P < 1 %) between the maximum stresses obtained in both methods. With linear compression, for a meat sample submitted to a 0.2 strain, myofibrillar structure developed a maximum stress whi ch was about 35 N/cm(2) when measurements were done near rigor mortis. This value decreased to about 4 N/cm(2) when meat was aged. Theses va lues of stresses were slightly lower than those obtained with sinusoid al compression. The two methods were as suitable for measurement of me at ageing. Nevertheless they did not give exactly the same stresses va lues because samples were not tested with the same strain history in b oth method and meat has a slight speed-dependent mechanical behaviour.