High internal phase Pickering emulsion (HIPPE) is a type of emulsion stabilized by solid particles irreversibly adsorbed on an interfacial film, and the volume fraction of the dispersed phase (Φ) is larger than the maximum packing volume fraction (Φ_max). Proteins, polysaccharides, and their composite particles can be used as good particle stabilizers. The contact angle can most intuitively demonstrate the hydrophilicity and hydrophobicity of the particles and also determines the type of emulsions (O/W or W/O type). Particles’ three-phase contact angles can be adjusted to about 90° by compounding or modification, which is more conducive to emulsion stability. As a shear thinning pseudoplastic fluid, HIPPE can be extruded smoothly through 3D printer nozzles, and its high storage modulus can support the structure of printed products. There is huge potential for future applications in 3D printing of food. This work reviewed the biomacromolecules that can be used to stabilize food-grade HIPPE, the stabilization mechanism of the emulsions, and the research progress of food 3D printing to provide a reference for the development of advanced food products based on HIPPE.

Walnut protein is a high-quality vegetable protein with promising applications in the food industry; however, its potential is hindered by low solubility and associated properties. We utilized various physical modification techniques (cold plasma; ball milling; superfine grinding; ultrasound; wet ball milling; and high-pressure microjet) to enhance walnut proteins’ physicochemical and functional properties. The changes in particle size, microstructure, surface hydrophobicity, fluorescence, solubility, foaming, and emulsification were investigated. Cold plasma and ultrasound treatments minimally affected particle size and morphology. Cold plasma increased the particle size D_4,3 from 145.20 μm to 152.50 μm. Ultrasonication reduced the particle size D_4,3 to 138.00 μm. The variation was within ±10 μm, while the particle size of walnut protein significantly decreased after the other four modification treatments. The greatest variation in particle size was in the superfine grinding, with the D_4,3 being reduced to 23.80 μm. Ultrasound treatment converted the β-sheet into an α-helix, while the other methods transformed the α-helix into a β-sheet. The dispersion stability notably improved after wet ball milling and high-pressure microjet treatments, which was accompanied by a significant increase in solubility from 6.9% (control) to 13.6% (wet ball milling) and 31.7% (high-pressure microjet). The foaming and emulsification properties were also enhanced through these modifications (foaming improved from 47% to 55.33% and emulsification improved from 4.32 m²/g to 8.27 m²/g). High-pressure microjet treatment proved most effective at improving solubility in the functional properties of walnut protein. These findings are expected to help broaden the potential utilization of walnut protein in the food industry, including in beverages and emulsions.

This study reports the fabrication of Pickering emulsion gels stabilized by zein and curdlan (CU) and systematically elucidates the regulatory mechanisms of oil fraction and shearing parameters (temperature and duration) on their microstructure, mechanical properties, and stability. Results indicated that excessive oil content triggered pronounced flocculation and structural collapse, primarily attributed to insufficient interfacial coverage and compromised network continuity. An optimal dense network with superior cohesiveness was established at a shearing temperature of 60 °C, effectively entrapping oil droplets within the continuous phase. Furthermore, extending the shearing duration enhanced long-term stability by reducing droplet size, yielding a maximum oil binding capacity (OBC) of 78.9%. These emulsion gels exhibited remarkable stability against diverse environmental stressors, including thermal treatments, pH variations, and freeze-thaw cycles. This work expands the application of protein-polysaccharide complexes in food colloid science and provides a theoretical foundation for the development of novel low-fat food formulations based on emulsion gel systems.

In this study, zein–curdlan (CU) composite nanoparticles were fabricated via an anti-solvent precipitation method. The effects of preparation parameters, including the mass ratio, reaction pH, and temperature, on the physicochemical properties and emulsifying attributes of the composite particles were systematically investigated. Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) analyses revealed changes in the local molecular environment and molecular organization following zein–CU association, while particle size, zeta potential, and surface hydrophobicity measurements further demonstrated fabrication-dependent changes in the physicochemical characteristics of the composite particles. As the CU ratio increased, the zeta potential decreased to −25.5 mV, accompanied by a reduction in surface hydrophobicity, suggesting a more hydrophilic CU-associated particle surface. At pH 8, the particles showed the smallest size among the pH series (244.6 nm), which may be related to enhanced zein deprotonation and interparticle electrostatic repulsion under the tested conditions. A preparation temperature of 40 °C produced the smallest particles and the most favorable emulsifying properties among the temperatures examined. Overall, this work provides evidence for the formation and emulsifying performance of zein/CU composite particles, broadening the application of plant protein–polysaccharide complexes in food-grade Pickering emulsion systems.