Abstract: 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.

Key words: fish bone paste, colloid mill grinding, wet superfine grinding, myofibrillarlar protein, structural properties