State Key Laboratory of Food Science and Technology, 1800 Lihu Ave, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Ave, Wuxi, Jiangsu 214122, China.
State Key Laboratory of Food Science and Technology, 1800 Lihu Ave, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Ave, Wuxi, Jiangsu 214122, China.
Food Res Int. 2022 Dec;162(Pt B):112075. doi: 10.1016/j.foodres.2022.112075. Epub 2022 Oct 28.
Myofibrillar protein (MP) system with different dissociation degrees of actomyosin was constructed by addition of ATP and the effects of actomyosin dissociation on the physicochemical and gelling properties of MP sol during freeze-thaw cycles were investigated. The results showed that the salt soluble protein content of the dissociated sample with 5 mM ATP (5-pH 6.2 group) was lower than that of other groups under unfrozen state, while the fluorescence intensity and hardness of all dissociated groups were significantly lower (P＜0.05) than that of the control group. After five freeze-thaw cycles, the low-field nuclear magnetic resonance (LF NMR) revealed that the immobile water (T) in MP sol with 5 mM ATP (pH 6.9) has lower fluidity compared with the control group. In addition, rheological studies revealed that the G' (storage modulus) value at 90℃ of MP sol with 5 mM ATP (pH 6.9) showed less decrease than that of the other groups after five freeze-thaw cycles. Meanwhile, after five freeze-thaw cycles, scanning electron microscope (SEM) showed that the gel of the control group has large holes and rough structure, while the microstructure of sample with 5 mM ATP (pH 6.9) was more compact and uniform. The heat-induced gel of 5-pH 6.9 group had highest hardness and lowest cooking loss among the groups after five freeze-thaw cycles. Briefly, the dissociation of actomyosin before freezing could slow down the rate of MP denaturation and improve the gelling properties after freeze-thaw cycle.
通过添加 ATP 构建了具有不同程度肌球蛋白-肌动蛋白解离程度的肌原纤维蛋白 (MP) 系统，并研究了肌球蛋白-肌动蛋白解离对 MP 溶胶在冻融循环过程中理化性质和胶凝特性的影响。结果表明，在未冻结状态下，5 mM ATP（5-pH 6.2 组）解离样品的盐溶性蛋白含量低于其他组，而所有解离组的荧光强度和硬度均显著低于（P＜0.05）对照组。经过五次冻融循环后，低场核磁共振（LF NMR）表明，与对照组相比，含有 5 mM ATP（pH 6.9）的 MP 溶胶中的不可动水（T）流动性较低。此外，流变学研究表明，在 90℃下，含有 5 mM ATP（pH 6.9）的 MP 溶胶的 G'（储能模量）值在经过五次冻融循环后比其他组的下降幅度更小。同时，经过五次冻融循环后，扫描电子显微镜（SEM）显示，对照组的凝胶具有较大的孔和粗糙的结构，而含有 5 mM ATP（pH 6.9）的样品的微观结构更加紧密和均匀。在经过五次冻融循环后，5-pH 6.9 组的热诱导凝胶具有最高的硬度和最低的蒸煮损失。总之，在冻结前肌球蛋白-肌动蛋白的解离可以减缓 MP 变性的速度，并提高冻融循环后的胶凝特性。
