Quality change during processing of dried yak meat in pastoral areas of Gansu

To study the quality change of yak meat during natural freeze-drying process in Gansu pastoral area. The semimembranosus were selected to analyse the changes of the physicochemical, nutritive and edible quality during spontaneous freeze-drying 0⁶0 d.The results showed that p H was increased and not significant after freeze-drying for 30 d ( p > 0.05) , the water activity ( Aw) and the moisture content were significantly decreased ( p < 0.05) , and Aw down to 0.46 at 30 d. With the extension of processing time, the content of protein and fat increased significantly ( p < 0.05) . The content of essential amino acids, threonine, lysine, leucine and nonessential amino acids, glycine, arginine, proline, serine glutamic acid and histidine in dried yak meat were higher than those in raw meat. The EAA/TAA ( essential amino acids/total amino acids) and the EAA/NEAA ( essential amino acids/non essential amino acids) in dried yak meat were 41.17% and 69.64% respectively.Evaluation of nutrition value of fatty acids showed that the P: S ( polyunsaturated fatty acid/saturated fatty acid) in dried yak meat was0.36, slightly lower than the ideal value. It's n-6/n-3 was 1.95, which was in the ideal range. The hardness, cohesiveness, cohesiveness and chewiness of dried yak meat increased significantly ( p < 0.05) , and the elastic and resilience decreased significantly ( p < 0.05) .It showed that the dried yak meat basically retains the nutrients of raw meat, which was a high protein, chewy and storable semi dry meat product.