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.

Dephenolized cottonseed protein is a high-protein product obtained through the further dephenolization of cottonseed meal or by removing the lint and shell of cottonseed, extracting the oil at a low temperature, and subsequently eliminating toxic substances (gossypol). This paper presents a review of the latest advancements in the dephenolization methods, quality characteristics, and application domains of dephenolized cottonseed protein. It focuses on enhanced dephenolization methods, and summarizes the composition, structural characteristics, functional properties, and recent research developments. Additionally, it identifies challenges, opportunities, and new directions for future research on dephenolized cottonseed protein, which will contribute to advancing the field of dephenolized cottonseed protein research.

Microfluidic technology, as a continuous and mass preparation method of nanoparticles, has attracted much attention in recent years. In this study, zein nanoparticles (ZNPs) were continuously fabricated in a highly controlled manner by combining a microfluidics platform with the antisolvent method. The impact of ethanol content (60~95%, v/v) and flow rates of inner and outer phases in the microfluidics platform on particle properties were examined. Among all ZNPS, 90%-ZNPs have the highest solubility (32.83%) and the lowest hydrophobicity (90.43), which is the reverse point of the hydrophobicity of ZNPs. Moreover, when the inner phase flow rate was 1.5 mL/h, the particle size decreased significantly from 182.81 nm to 133.13 nm as the outer phase flow rate increased from 10 mL/h to 50 mL/h. The results revealed that ethanol content had significant impacts on hydrophilic–hydrophobic properties of ZNPs. The flow rates of ethanol–water solutions and deionized water (solvent and antisolvent) in the microfluidics platform significantly affected the particle size of ZNPs. These findings demonstrated that the combined application of a microfluidics platform and an antisolvent method could be an effective pathway for precisely controlling the fabrication process of protein nanoparticles and modulating their physicochemical properties.

The integration of plant-based foods with 3D printing technology offers a revolutionary solution for addressing future food security, sustainable manufacturing, and personalized nutrition. However, the inherent rheological limitations and processing instabilities of native plant proteins remain critical bottlenecks restricting their widespread adoption in additive manufacturing. This review aims to systematically summarize the research progress of plant protein-based materials across three primary food 3D printing technologies: Binder Jetting (BJT), extrusion-based printing, and inkjet printing. First, the forming and stabilization mechanisms under different printing modes are critically analyzed, focusing on the powder–binder interfacial wetting in BJT, the shear-thinning and thixotropic recovery of emulsion gels in extrusion, and the piezoelectric jettability and rapid gelation kinetics of hydrogels in inkjet printing. Second, strategies to optimize the printability of plant proteins via molecular modification (e.g., enzymatic hydrolysis, covalent/non-covalent cross-linking) and multi-scale structural design (e.g., polysaccharide complexation, bimodal particle size distribution) are elaborated. The review further showcases innovative applications in whole-cut meat analogues, personalized dysphagia diets, and functional bioactive carriers. Finally, the challenges regarding food safety (microbial and allergen risks), regulatory lag, and consumer acceptance are critically discussed. Future perspectives highlight the immense potential of multi-material co-extrusion, 4D printing, and Artificial Intelligence (AI)-driven inverse formulation design in accelerating the industrialization of plant-based food 3D printing.