鱼骨泥残留肌原纤维蛋白在加工过程中结构及性质的变化

依次利用胶体磨细粉碎(简称细粉碎)和湿法超微粉碎(简称超微粉碎)逐级粉碎方式制备鱼骨泥,提取不同工艺阶段骨泥中的肌原纤维蛋白,以肌原纤维蛋白溶解度、粒度、浊度、活性巯基含量、表面疏水性和相对二级结构含量等为指标,研究鱼骨泥加工过程中肌原纤维蛋白结构性质的变化。结果显示:不同阶段加工工艺对鱼骨泥中肌原纤维蛋白结构性质影响显著,其中超微粉碎对骨泥中肌原纤维蛋白结构性质影响较大,细粉碎对蛋白结构性质影响相对较小。逐级粉碎可以显著提高鱼骨泥中肌原纤维蛋白的溶解度;在胶体磨剪切力作用下,肌原纤维蛋白粒径显著减小,而经超微粉碎后,由于蛋白质结构的破坏和聚集作用,肌原纤维蛋白粒径会显著增加,由299.4 nm增至464.5 nm,同时浊度也随之升高;细粉碎后活性巯基含量和表面疏水性均显著下降,但随着超微粉碎次数增加,活性巯基含量和表面疏水性均呈现先升高后下降的趋势;细粉碎使肌原纤维蛋白α-螺旋结构比例由64.21%增加到79.99%、β结构比例下降,而超微粉碎可破坏α-螺旋结构,使其部分转变成β结构。

Changes in Structural Properties of Myofibrillarlar Proteins during the Processing of Fish Bone Paste

Superfine fish bone paste was prepared by sequentially using colloid mill grinding and wet superfine grinding. Myofibrillarlar proteins from fish bone paste were extracted to investigate the changes in structural properties during the processing of bone paste through the determination of solubility, particle size, turbidity, active sulfhydryl content, surface hydrophobicity, and secondary structures. The results showed that processing methods significantly affected myofibrillar proteins in fish bone paste, and wet superfine grinding showed a bigger impact on structural properties of myofibrillar proteins than colloid mill grinding. The solubility of myofibrillar proteins was enhanced after sequential grinding. The particle size reduced under the shear stress of colloid mill grinding, and then increased obviously from 299.4 to 464.5 nm after wet superfine grinding, accompanied with an increase in turbidity. The active sulfhydryl content and surface hydrophobicity were decreased after colloid mill grinding, but both of them firstly rosed then declined with the increase of wet superfine grinding time. The proportion of α-spiral in secondary structure increased from 64.21% to 79.99%, while β structure proportion decreased after colloid mill grinding, and wet superfine grinding could degrade part of the α-spiral structure and turned it into β structure.