Emerging Strategies for Tailoring Functionality in Protein-Polysaccharide Biocomposite Films for Food Packaging: A Review.

Environmental concerns regarding petroleum-based plastics have accelerated the search for renewable food packaging materials. Protein-polysaccharide composites are strong candidates due to their inherent biodegradability and film-forming properties. Blending these biopolymers offers a pathway to balanced structural and functional performance; yet practical application remains limited by poor moisture resistance, limited mechanical stability, and interfacial incompatibility. This review critically examines recent advances in double-based protein-polysaccharide composite films, with particular emphasis on the effectiveness of current modification strategies. On the basis of findings, hydrophobic compounds primarily improve water-vapor barrier properties, nanomaterials are more effective for mechanical reinforcement, and treatments, such as Maillard-type cross-linking, pulsed electric field, cold plasma, and ultrasound, can improve film network structure through modified intermolecular interactions. A critical limitation in existing research is the lack of a standardized framework that links specific structural defects to optimal modification pathways. This review addresses this gap and proposes future priorities: improving phase compatibility, developing scalable green processing, and validating film performance under real food packaging conditions.