Upcycling Fish Bone into Novel Engineered Particle Stabilizers for Fish Oil-Based Pickering Emulsions: A Dual-Valorization Approach for Resource Recovery

Abstract Effective recycling of fish processing by-products as new high-value resources is of great significance to promoting the circular economy. Herein, a resource loop strategy for the dual valorization of fish bone and fish oil, employing top-down, ball-milled fish bone particles (FBPs) as a Pickering stabilizer to create stable fish oil-based emulsions, was presented, which further improved the inherent instability of emulsified surimi gels (ESGs) as a quality reinforcing agent. Results showed that extending the ball milling duration from 5 to 60 min significantly reduced the average particle size of FBPs from 1772.9 to 219.7 nm and increased their absolute value of zeta potential. Spectroscopic analysis confirmed FBPs composed of native hydroxyapatite−collagen composites, with prolonged ball milling disaggregating the mineral-organic matrix. Additionally, ball-milled FBPs could serve as engineered particles to stabilize fish oil-based Pickering emulsions, with emulsion stability influenced by particle concentration and oil−water ratios. At a particle concentration of 3.0 wt % and an oil−water ratio of 0.6, the FBPs milled for 20 and 30 min (FBPs-20 and FBPs-30) exhibited superior adsorption at the oil−water interface compared to other samples, forming dense microstructures around emulsion droplets. Such interfacial structures limited the migration of water/fish oil and exhibited unique viscoelastic properties. Finally, 6 wt % FBPs-30-based emulsion enhanced the textural attributes of ESGs, illustrating their potential as functional additives. Thus, the findings present a versatile strategy for fish-based by-products for fabricating nanoparticles, delineating a tangible waste-to-wealth paradigm for closing critical resource loops in sustainable food production.