Enhancing gel and 3D printing performance of lipid-enhanced skipjack tuna (Katsuwonus pelamis) surimi via Pickering high internal phase emulsion

This study explored the effect of lactoferrin (LF)-stabilized fish oil Pickering high internal phase emulsions (HIPPEs) on the gel property and 3D printing performance of skipjack tuna surimi compared with directly added fish oil. Based on the various environmental stress stability, HIPPEs could remain relatively stable when added to surimi gels. The luminance and whiteness of skipjack tuna surimi gel were significantly (p < 0.05) elevated after adding HIPPEs. Compared with directly added fish oil, the texture properties, gel strength and water holding capacity of surimi gels were notably (p < 0.05) increased after adding HIPPEs, and more free water changed into bound water and non-fluidizable water. Moreover, more α-helix turned into β-sheet, and the disulfide bond content was increased. The microstructure indicated that the tiny oil droplets of HIPPEs were more evenly distributed in the surimi gel network, while directly added fish oil caused the larger droplets aggregation and damaged the gel network structure. Higher viscoelastic modulus and apparent viscosity endowed surimi with better 3D printing accuracy and stability. Consequently, HIPPEs improved the quality of skipjack tuna surimi gel, which could provide a direction for developing of new skipjack tuna products.