Protein-gum-based gels: Effect of gum addition on microstructure, rheological properties, and water retention capacity

Gelling is an important way to texturizing, develop novel products, and carry bioactive compounds in the food industry. Some proteins and gums demonstrate gelling character. However, when they are mixed, the properties of the resulting gel may be improved even when some gums not gelling alone. There are many reviews in literature centered on protein-polysaccharide interactions and the use of such mixed systems as complexes. Although, the mixed gelation and particularly the effect of gum addition on the gel properties, have been scarcely approached. This review focused on the most used natural gums for food gelling purposes and their effect on the microstructure, rheological properties, and water retention capacity of mixed gels to serve as a guide for the design of gelling mixed systems. This insight can allow protein-gum-based gel properties to be tuned for specific food applications. Gum addition to a protein system induces structural changes in the tridimensional red of the gel that can improve its rheological properties and water holding capacity depending on the structure, molecular weight, density, and nature of the charge of the biopolymers used. Additionally, pH, ionic strength, protein-gum ratio and concentration of the gum are critical factors during gel formation.