Abstract:To investigate the effects of different pressure cooking on the texture and microstructure of yak rumen smooth muscle，yak rumen smooth muscle was cooked under pressures of 0.15，0.20 MPa and 0.24 MPa for 10 min.The changes in cooking loss，thermal shrinkage，shear force，texture，collagen content and microstructure of yak rumen smooth muscle under different pressures were determined，followed by correlation analysis.The results showed that with increasing pressure，the cooking loss，shear force，hardness，adhesiveness，chewiness and collagen content of yak rumen smooth muscle significantly decreased，while elasticity significantly increased.Thermal shrinkage and cohesiveness showed an increasing trend，but the differences were not significant.Microstructural analysis revealed that with increasing pressure，the muscle fibers of yak rumen smooth muscle went from intact to fragmented，the fascicles became thicker，and the gaps between muscle fibers and fascicles decreased.Correlation analysis indicated that，except for thermal shrinkage and cohesiveness，the correlation coefficients between pressure magnitude，collagen content，and various indicators of yak rumen smooth muscle were all above 0.8，suggesting that pressure and collagen content had a significant influence on the quality of yak rumen smooth muscle.In conclusion，the edibility and microstructure of yak rumen smooth muscle decreased with increasing pressure，and yak rumen smooth muscle cooked under 0.20 MPa exhibited better edibility.