Research On Yak Meat Maturation Mechanism And Meat Quality After Slaughter

In this study, seven health Yak were selected randomly with 36-48 months from the field(slaughtered in accordance with the average age of local Yak,4 males,3 dams) in Sunan grassland as test group and seven local cattle(slaughtered in accordance with the average age of local Cattle,4 males,3 dams)as control group. Slaughtered according to the requirements of quarantine system strictly. After slaughtered then picked the longissimus,psoas major and other parts in Sunan CaoYuan HuiCheng Food Company. Curenttly, maturation mechanism of Yak meat is still was hot spots of meat research, this study based by previous studies, in the postmortem aging, by pH values,meat color,water lose rate,shear force,glycogen content,myofibril fragmentation index(MFI),Calpain and muscle ultrastructure changes were generally analyzed and researched,then analyzed correlation analysis between the indicators, the purpose of study was to generally acquire maturation mechanism of Sunan Yak, the results of research can provide reference for breed choicd-cultivation,developing the product quality and improving meat tenderness. The results were showed as below:1.The pH value of Yak's meat was decreased significantly during 1～4 days after slaughter, during 4～8 days remained stable, it decreased to minimal value is 5.53 on 4^th day after slaughter; Shear force of Yak's meat increased to maximum value is 5.39Kg 3^rd day after slaughter (The most extent of titanic),Yak's meat will be in the people acceptable range during 4 days after slaughter, so could be consider the meat of yak achieved maturation. The changes of muscle ultrastructure comfort to it. yak's meat has a faster change in pH value than the cattle's meat.2.Water lose rate of Yak's meat was significantly lower than cattle's meat(P﹤0.05).Meat color a* value of Yak's meat color was significantly higher than cattle's meat,but meat color L* value and b* value of Yak's meat color was significantly lower than cattle's meat(P﹤0.05).There were significant correlation among water lose rate and L*,a*value, this is because water lose rate increase, a lot of water effluent and accumulate in meat surface, lead to L* value increase. Besides any pigment material, so a* value decrease, Yak's meat had been achieved maturation on 4^th day after slaughter, L* value was 38.76, b* value was 12.26, a*value was 16.08, showed the meat of Yak was deep red and well water hold capacity. 3.The Yak's meat and cattle's meat glycogen content decreased gradually during 3～5 days after slaughter, then because glycogen content of Yak's meat cumulate consume so it was stable, CAF was high 3～5 days after slaughter then changed slowly, because calpain occurred autolysis and degradation, MFI increased significantly after 2^ed day, Myofibrillar fragmentation was higher degree, indicated the meat of Yak was better tenderness, which coincide with the trends of shear force.4.These were negative significant correlation among pH value, meat color a* and the shear force of Yak's meat, significant correlation among MFI, water lose rate, meat color L*value, CAF and MFI,Those correlations could provide as reference for control meat quality during aging process and improving eating quality.