The Effect Of Meat Quality And Calpains Activity Of Yak In Different Ages

It is a special environment to yak which has different slaught ages, and there is asiginificant difference between yak meat of different ages and edible quality, nutritionalquality, fatty acid, amino, mineral substance and calpains activity. The research determinedthe nutritional quality, fatty acid, amino, mineral substance and calpains activity of yak meatin different ages. The results showed:1. There were major changes in edible quality as yak get older. The longer the ages ofyak, the deeper the meat color, the more plentiful the marble, At the age of7, two of the scorewas7.8±0.21and2.56±0.23. However, according to color grading and marbling score, thereis a distance to reach the ideal score which finished cattles have. So, meat color and marblecouldn’t act as index to evaluate the edible quality of yak meat.2. The longer the ages of yak, the increase the shear force values and muscle fiberdiameter with significant differences(p<0.05), At the age of7,the the shear force values was(9.42±0.28)kgf, was twice that of3years old. The tenderness and sensory quality of meatcould drop.When the meat matured, the muscle fiber diameter values could reduce, thus thetenderness of meat was improved. water holding capacity and cooked rate raised, water lossrate dropped.3. The longer the ages of yak, the moisture content decreased gradually, the fat contentand the protein content increased gradually with significant differences(p<0.05), Ash contenthad no significant change.4.The composition of fatty acid was not significant difference with yak meat of differentages. SFA accounted for more than50%of the total fatty acid content, higher than that ofUFA. The longer the ages of yak, the higher the content of SFA, the lower the content of UFA,and siginificant difference(p<0.05). The longer the ages of yak, the higher the content ofamino acid. At the age of4-5, the content of amino acid was reduced, and at the age of7, thecontent of amino acid was higest. All the different ages yak meat’s amino acid score did notreach the ideal amino acid score.5.There was a siginificant effect on minerals of yak meat of different ages, The longerthe ages of yak, the higher the content of K, Ca, Mg, Fe, Zn, Mn, Cu, and siginificantdifference(p<0.05). There was a siginificant effect on the activity of Calpains (P <0.05),before the physiological maturity, the activity of Calpains was low. At the age of4-5, it wasachieved the highest, then a downward trend. Above all, It was suggested that there were significant effects of yak quality in differentages, and provided theoretical basis and technical supports of yak grade evaluation methodsand standards. Different slaughter ages, as an important factor of yak meat rating method infuture, also for the establishment of the yak meat classification system provides a certaintechnical support.