Abstract: The effects of high-pressure homogenization (HPH) at different pressures (30, 40, 50 and 60 MPa) on the hydration properties and crystallinity of bamboo shoot dietary fiber (BSDF) were studied as well as the effect of HPH-treated BSDF on the gel strength, water-holding capacity (WHC), protein secondary structure, chemical interactions and microstructure of heat-induced gels from shrimp surimi. The results showed that the WHC, oil-holding capacity (OHC), and swelling capacity of BSDF were positively correlated with homogenization pressure (P < 0.05). However, too small size of fiber particles affected its combination with hydrophilic groups, which could reduce the water absorption and swelling properties. X-ray diffraction (XRD) and scanning electron microscopic (SEM) results demonstrated that the crystallinity of BSDF decreased after medication, and the fiber bundle structure was destroyed, becoming loose and porous. Compared with the surimi added with unmodified BSDF, the gel strength of shrimp surimi added with BSDF treated at 30, 40, 50, and 60 MPa were increased by 10.04%, 17.87%, 28.76%, 28.49%, and WHC increased by 3.48%, 5.74%, 13.04%, and 12.70%, respectively. Fourier transform infrared (FTIR) spectral analysis showed that the contents of α-helix and random coil in the modified BSDF-supplemented shrimp surimi gel decreased, while the contents of β-sheet and β-turn increased significantly, suggesting more stable secondary structure of proteins. The results of chemical interaction analysis showed that modified BSDF promoted the hydrophobic interactions and the formation of disulfide bonds in shrimp surimi gel, with a more pronounced effect being observed with BSDF treated at 50 and 60 MPa. SEM results showed that shrimp surimi gel added with BSDF treated at 60 MPa had a more uniform and denser three-dimensional network structure. These results showed that HPH treatment could improve the hydration properties, and reduce the crystallinity of BSDF, and HPH-treated BSDF could significantly enhance the gelation properties of heat-induced shrimp surimi, which will provide a theoretical basis for improving the application of BSDF in shrimp surimi gels.

Key words: bamboo shoots dietary fiber; high pressure homogenization; gelation properties; chemical interactions; protein secondary structure; microstructure