Tuning the Functional Properties of Polysaccharide-Protein Bio-Based Edible Films by Chemical, Enzymatic, and Physical Cross-Linking
Résumé
Among natural biopolymers, polysaccharides and proteins are very promising for biodegradable and edible wraps with different characteristics, so that their formulations can be tailor-made to suit the needs of a specific commodity. Films prepared from polysaccharides have good gas barrier properties but exhibit lower resistance to moisture compared to protein films (edible) or polylactide films (biodegradable). Protein-based films show better mechanical and oxygen barrier properties compared to polysaccharide films. For that reason, film performances may be enhanced by producing blend systems, where hydrocolloids (mixtures of proteins and/or polysaccharides) form a continuous and more cohesive network. However, the lower water barrier properties of hydrocolloid films and their lower mechanical strength in comparison with synthetic polymers limit their applications in food packaging. Therefore, the enhancement of biopolymer film properties has been studied to attain appropriate applications. This review provides an extensive synthesis of the improvement of the properties of edible polysaccharide-protein films by way of various chemical, enzymatic, and physical methods. These methods primarily aim at improving the mechanical resistance. They also permit to ameliorate the water and gas barrier properties and related functional properties.
Mots clés
Chemical cross-linking
Enzymatic cross-linking
Functional properties
Heating and irradiation cross-linking
Protein-polysaccharide films
Electron-beam irradiation
Water-vapor permeability
Wheat gluten films
Gamma-irradiation
Mechanical-properties
Fish gelatin
Transglutaminase treatment
Biomedical applications
Barrier properties
Caseinate films