Plant protein-based hydrogels and oleogels: A review of sources, formation, and emerging applications

Plant proteins from cereals, legumes, and oilseeds have emerged as promising sustainable alternatives to animal proteins. They can form hydrogels and oleogels with tunable structural and functional properties for food and biomedical applications. However, most studies focus on specific proteins or individual gel types, lacking a comprehensive understanding across aqueous and lipid systems. This gap in linking composition, assembly, and structure-function relationship hinders both mechanism elucidation and application design. This review provides an integrated analysis of how composition and structure influence the gelling behavior of plant proteins. We specifically compare the mechanisms of hydrogel formation via physical, chemical, and enzymatic crosslinking with oleogel fabrication achieved through direct and indirect dispersion methods. Moreover, this review critically discusses recent advances in their functional applications, as well as opportunities and challenges in developing multifunctional, sustainable plant protein-based gel systems. This review elucidates the methods and mechanisms underlying the formation of plant protein hydrogel and oleogel networks. Despite diverse sources, a common denaturation/unfolding-and-association mechanism drives network formation, while globular structures limit functionality. Approaches like blending with polysaccharides, enzymatic crosslinking, and physical structuring are effective for enhancing gelation; however, achieving precise control over the hierarchical structure and network properties remains a key challenge. Further efforts should focus on integrating molecular design, process engineering, and interfacial control, which will be crucial for enhancing structural tunability and broadening the practical applications of plant protein-based gels in food and biomedical fields. • Plant protein-based gels show great potential in food and bio-related applications. • Hydrogels can be formed via physical, chemical, and enzymatic cross-linking. • Oleogels are fabricated through direct and indirect structing approaches. • Current challenges and future directions for plant protein gels are summarized.