猪PSE肉和正常肉与淡水鱼MfATPase热稳定性的比较研究

本文对猪PSE肉和正常肉与淡水鱼MfATPase热稳定性进行比较研究。通过肌原纤维悬浊液分别于35℃保温不同时间和不同温度保温30min的Ca2+-ATPase活性测定,结果表明:肌原纤维Ca2+-ATPase活性随盐浓度增加而酶活性减少;盐浓度相同时,Mg2+-ATPase>Ca2+-ATPase。鱼肉肌原纤维的Ca2+、Mg2+-ATPase比活性较猪肉高,正常肉的MfATPase活性比PSE肉高。MfCa2+-ATPase活性随保温时间、保温温度的增加而减少,但温度对肌原纤维Ca2+-ATPase活性影响比时间对其的影响更显著,在45℃时,鱼类的MfCa2+-ATPase一级失活常数KD比猪要大得多,鲢鱼的肌原纤维蛋白质对热最敏感即最易变性,猪正常肉的热稳定性最好,由此可作为特征参数并用于肌肉种类的鉴别。

Comparison of Myofibrillar ATPase Thermostability in PSE-Pork and Normal Pork with Freshwater Fish Muscle

The objective of this study was the comparison of thermo-stability of myofibrillar ATPase in PSE- Pork and normalpork with freshwater fish muscle. When the myofibril suspending solution was stored at 35℃ for various times and at differenttemperatures for 30 minutes, the Ca2+-ATPase activity was studied. The results indicated: with the increasing of salinity ,themyofibrillar Ca2+-ATPase decreased, but when in the same salinity, Mg2+-ATPase>Ca2+-ATPase. With the increase of incubationtime and temperature, the myofibrillar Ca2+-ATPase activity decreased. However, the effect of temperature on myofibrillar Ca2+-ATPase activity was more apparent than incubation time. At 45℃, the first order rate constants(KD) of myofibrillar Ca2+-ATPaseof cold blooded animal (fish)was larger than warm blooded animal (pork). The thermo-denaturation of silver carp myofibrillarprotein was the worst while, thermo-stability of the normal pork was the best. So the myofibrillar ATPase could be used as acharacteristic parameter to distinguish the muscle species.