南海鸢乌贼肌原纤维蛋白加热过程中理化性质的变化

为研究南海鸢乌贼Symplectoteuthis oualaniensis肌原纤维蛋白在加热过程中理化性质的变化,以南海鸢乌贼胴体肌肉为原料,对其肌原纤维蛋白在加热过程中浊度、溶解度、Ca~(2+)-ATPase活性和总巯基(-SH)含量进行了测定,并对该蛋白质在整个加热过程中SDS-PAGE电泳图的变化进行了研究。结果表明:在25~35℃时,鸢乌贼肌原纤维蛋白的浊度、溶解度、Ca~(2+)-ATPase活性、总巯基含量的变化均比较缓慢;在35℃后继续升温,浊度、Ca~(2+)-ATPase活性、总巯基含量均发生明显变化;总巯基含量在40~50℃时出现短暂升高现象后又急剧降低,溶解度在50℃时开始明显降低;在25~35℃时,随着温度的逐渐升高,鸢乌贼肌原纤维蛋白的肌球蛋白重链(MHC)略有减少,副肌球蛋白(PM)和肌动球蛋白(Actin)基本上未发生变化,但在35℃后,鸢乌贼肌原纤维蛋白开始产生大分子物质,逐渐发生变性。

Physiochemical changes in myofibrillar protein from purplebackflying squid Sthenoteuthis oualaniensis in South China Sea during heat-treatment

The changes in physiochemical properties and SDS-PAGE of myofibrillar protein from purpleback flying squid Sthenoteuthis oualaniensis in South China Sea during heat-treatment were studied via turbidity, solubility, Ca2+-ATPase activity and total sulfhydryl content. The results showed that the changes in all the above indicators was inconspicuous at heating temperature of 25-35 ℃. There were significant changes in turbidity, Ca2+-ATPase activity and total sulfhydryl content at 35℃. The total sulfhydryl content was shown to be increased at 40-50℃ in short period, and then reduced significantly at 50 ℃ again, with significant decline in solubility. Myosin heavy chain( MHC) of myofibrillar protein from purpleback flying squid in South China Sea showed some degradation as raising temperature, but the paramyosin ( PM) and actin remained unchanged basically. At 35 ℃, the myofibrillar protein of purpleback flying squid began to form macromolecular substances and denatured gradually.