Functional Hydrogels in Food Applications: A Review of Crosslinking Technologies, Encapsulation Trends, and Emerging Challenges

Hydrogels derived from natural and synthetic polymers have emerged as versatile materials with wide applications in food science, biotechnology, and health-related sectors, providing unique opportunities to encapsulate, protect, and deliver bioactive compounds, as well as to create new textures and functional properties in food systems. This review summarizes the latest advances in the design and application of hydrogels, highlighting the critical relationship between polymer structure, crosslinking strategies, and functional performance. The analysis reveals that while significant progress has been achieved, challenges persist in scaling laboratory-scale hydrogel systems to industrially relevant processes, where stability, reproducibility, and regulatory acceptance remain major bottlenecks. Emerging directions in the field include the development of smart hydrogels that respond to environmental stimuli (pH, temperature, or enzymatic activity), sustainable fabrication routes using renewable biopolymers, integration with advanced processing technologies such as 3D printing or microfluidics, and biorefinery approaches emphasizing their role in valorizing agro-industrial by-products into high-value functional materials. Hydrogels represent a promising platform at the interface of polymer science, food technology, and biotechnology, whose continued development will depend on multidisciplinary innovation aiming to meet consumer demands for sustainable, safe, and health-promoting food systems.