Phycocyanin and Psyllium Fiber-Based Gel Systems: Rheology and Functional Applications in Emulgels Containing Algal Oil

Abstract

This study examines the rheological and structural characteristics of dispersions prepared from phycocyanin extract and psyllium fiber, with a particular emphasis on their potential applications in algae oil-in-water emulgels. The initial step involved the implementation of an experimental design, the objective of which was to examine the rheological characteristics of the dispersions in relation to the concentrations of algae extract and fiber. Subsequently, emulgels were formulated with phycocyanin and psyllium as stabilizers and algal oil as the dispersed phase. All dispersions exhibited shear-thinning behavior. The viscosity of the dispersions increased with the concentration of psyllium, but decreased with the concentration of phycocyanin. The results of the oscillatory tests demonstrated that the dispersions exhibited predominantly elastic behavior, with the elastic modulus exceeding the viscous modulus. The psyllium concentration proved to be the primary factor influencing the enhancement of gel-like properties, whereas the phycocyanin concentration exerted a detrimental effect on these characteristics. The microstructural analysis corroborated these findings, demonstrating the formation of a denser network in the psyllium-rich dispersions and the emergence of a more porous structure with the addition of phycocyanin. In emulgels, a droplet size distribution analysis indicated that phycocyanin reduced droplet size, while psyllium increased it. In terms of rheological properties, the emulsions exhibit enhanced rheological properties compared to their corresponding continuous phases. Stability tests confirmed that higher concentrations of both components enhanced emulgel stability. These findings suggest that psyllium-phycocyanin dispersions may be a promising avenue for developing stable, structured emulsions with potential applications in food and pharmaceutical products.