鲢肌肉在保藏中的生化变化

Biochemical changes in muscle of silver carp during storage

以淡水鱼鲢为对象 ,研究其在 5℃、10℃、和 2 0℃保藏时鱼肉的pH值、ATPase活性、糖原、乳酸含量变化 ,肌原纤维蛋白的变性和降解情况及鱼体的感官变化。实验结果表明 :( 1)鲢肌肉糖原含量低 ( 8.2 μmol/g) ,并在 3～ 6h内迅速降解。 ( 2 )鲢肌肉乳酸含量也低 ,在低温保藏下乳酸易于积累。 ( 3)新鲜鱼肉的pH值为6 .97左右 ,接近中性 ;保藏过程中pH值下降的幅度小 ,最低可下降到 6 .6左右。 ( 4) 5℃和 10℃保藏条件下蛋白质稳定性好 ,未见ATPase活性的降低和肌球蛋白重链的降解 ,2 0℃保藏时 ,48h后发现肌球蛋白重链的显著降解。

The variations in sensory evaluation,pH value,ATPase acticity,contents of glycogen and lactic acid,as well as the denaturation and degradation of myofibrillar protein in the muscle of silver carp stored at 5℃, 10℃and 20℃were investigated.The experimental results showed that:(1)The content of glycogen was low (8.2μmol/g) in fresh fish and declined quickly in 3-6 hours;(2)The content of lactic acid was low and lactic acid accumulated at low temperature storage;(3)pH value of fresh fish was nearly neutral,about 6.97,and the change of pH value small.pH value possiby declined to 6.6 during storage;(4)Fish myofibrillar protein showed stable during storage at 5℃ and 10℃ without the decrease of ATPase activity and the degradation of myosin heavy chain(MHC),but MHC degraded markedly when stored at 20℃ for 48 hours.