Functional Chia Oil-in-Water Emulsions Stabilized with Chia Mucilage and Sodium Caseinate

The objective of this research was to study the effect of adding different concentrations of chia mucilage (0%, 0.30%, or 0.80%, wt/wt) and sodium caseinate (NaCas) as emulsifying agents (0.1%, 0.5%, 2.0%, or 5.0%, wt/wt) on the stability of oil-in-water (O/W) emulsions (10:90, wt/wt) as a function of storage time, at room temperature. The emulsions were characterized by determining the evolution of backscattering profiles, the particle-size distribution, and microscopic observations. The most stable emulsions over the storage period were those with 0.80% of the chia mucilage concentration. These emulsions also presented a bimodal particle-size distribution, while the emulsions without chia mucilage exhibited a monomodal distribution. The De Brouker mean diameter (D) [4,3] of all the emulsions decreased with increasing NaCas concentrations and they increased with storage time, mainly for the emulsions with the lowest chia mucilage and the emulsifying agent concentrations. The optical micrographs showed a high destabilization in the emulsions with low concentrations of chia mucilage and NaCas. The results suggest that the addition of chia mucilage to O/W emulsions confers more stability to the emulsions, as a function of increase in the mucilage concentration. The addition of NaCas also showed a greater stability with increasing concentration for both emulsions (with and without chia mucilage).