Fibrous protein gels: Nanoscale features governing gelation behavior and gel properties

Protein fibrils, as nanoscale structures with high aspect ratios, exhibits superior physical properties—such as gelation, emulsification, stability, and foaming—compared with traditional protein gels. This review explores the properties, mechanisms, and recent advancements related to protein fibrils in gels. It begins by outlining the fibril formation process and detailing factors influencing this process, such as pH, temperature, heating time, ionic strength, protein concentration, chaotropic agent, shear forces, pressure, and ultrasound. Then, the conditions for gel formation and the properties of single-component fibrous gels are examined, with a focus on the decisive impact of fibril morphology, particularly length, on gel mechanical properties. Further, the review discusses polysaccharide-enhanced protein fibril hydrogels, polyphenol-enhanced protein fibril hydrogels, and protein fibrils as gel reinforcers, highlighting significant improvements in mechanical strength and stability. It also covers recent applications of fibrous gels in delivery systems, edible coatings, wound dressings, and tissue engineering scaffolds. Finally, the promising prospects of protein fibrils are summarized. These structures impart gels with enhanced mechanical properties, stability, enzyme resistance, self-healing ability, antioxidant activity, and antibacterial effects, offering tremendous potential for applications across various fields.