牛、羊肌肉的显微结构及剪切力在高压处理下的变化

Changes of Microscopic Structure of Myofibrils and Shear Force Value of Bovine and Mutton Skeletal Muscle under Hydrostatic High-Pressure (HHP) Treatment

实验研究了超高压处理条件下牛、羊肌肉感官特性、显微结构及剪切力值的变化,并探讨了超高压处理对牛、羊肌肉的嫩化作用。在压力为700MPa,室温,保压20min的处理条件下,牛、羊肌肉显微组织结构变化明显:肌节发生明显收缩,牛肉肌节收缩率为34.8%,羊肉肌节收缩率达22.2%;同时肌原纤维的Z线断裂,M线降解,I带变白。高压处理后牛肉的剪切力值显著下降(p<0.05),羊肉的剪切力值显著下降(p<0.01),证明超高压处理对牛、羊肉具有嫩化作用。高压处理牛、羊肌肉的感官特性发生一定的变化:颜色变淡,弹性下降,并有轻微的类似“蒸煮”的风味,属于处理强度过量。只要压力、温度、保压时间选择适当,就可以达到杀菌、嫩化的目的,同时保持产品的天然风味。

Effects of hydrostatic high-pressure (HHP) treatment on sensory characteristic, microscopic structure of myofibrilsand shear force value of bovine and mutton skeletal muscle were studied. The function that HHP could promote meat tendernesswas also discussed. The sensory characteristics of bovine and mutton muscle varied a lot after HHP treatment: color faded,extension decreased and mortem flavor emerged. Under the condition of 700MPa pressure level, 25℃ and 20min of HHPtreatment,the remarkable variation could be seen in microscopic structure of myofibrils of bovine and mutton muscle. Sarcomereshrinkage occurred with obvious changes. The contraction rates of bovine and mutton sarcomere were 34.8% and 22.2%respectively. Meanwhile, Z-lines broke, M- lines degraded and I band became white. The shear force values of bovine(p<0.05)and mutton(p<0.01) skeletal muscle decreased remarkably. The research results indicated that HHP could improvethe tenderness of bovine and mutton skeletal muscle. The sensory characteristics of bovine and mutton muscle varied a lot afterHHP treatment: color faded, extensilility decreased and mortem flavor emerged. These changes were caused by too high treatmentof HHP. If the pressure, temperature and maintaining time were chosen properly, HHP could result in a goal of improvingtenderness, killing microorganisms and keeping the natural flavor of meat.