Authors : X.X. Shi, Q.L. Yu, L. Han, J. CH. Tian, L. Zhang, Y.B. Zhang and Z.H.B. Guo
Abstract: An experiment was conducted to investigate the effects of post mortem ageing on the changes of meat quality characteristics and calpains activities of Gannan yak (Bos grunniens) meat. Twelve, 3 years old yaks (body weight, 230±10 kg) were used in this study and Longissimus dorsi muscle was removed from the carcasses immediately after slaughter and cut into chops with an average weight of 50 g, vacuum-packed into pouches, taken to the laboratory under refrigerated conditions. The samples were aged at 4°C for 0, 12, 24, 48, 72, 120, 168 and 192 h, respectively. The results indicated that the pH value of meat fell gradually to the minimum of 5.56 within the first 72 h (p<0.05) and the value did not change in the next 120 h. Water Holding Capacity (WHC) had a decreased trend in the first 72 h (p<0.05) but was s since. Tenderness of yak meat was improved in ageing days evaluated by Shear Force (SF) and Myofibril Fragmentation Index (MFI) (p<0.05). Hardness, springiness and chewiness were significantly decreased by analyzing the texture profile which reflected the progressive softness of the meat (p<0.05). Activity of μ-calpain was decreased continuously in first 72 h and activity of m-calpain was declined slightly only in first 12 h. However, activity of calpastatin was stable in first 72 h and then decreased gradually. The results demonstrated that the meat quality properties of yak meat were improved during ageing after postmortem and μ-calpain might be the main contributor of tenderization.
X.X. Shi, Q.L. Yu, L. Han, J. CH. Tian, L. Zhang, Y.B. Zhang and Z.H.B. Guo, 2013. Changes in Meat Quality Characteristics and Calpains Activities in Gannan Yak (Bos grunniens) Meat during Post Mortem Ageing. Journal of Animal and Veterinary Advances, 12: 363-368.