Non-spherical microparticles from complex coacervation of rice or pea proteins and chia mucilage

Complex coacervation is a microencapsulation technique recognized by its low cost, high efficiency, and reproducibility. It involves interactions between oppositely charged biopolymers, such as proteins and polysaccharides. The present study evaluated the formation of non-spherical microparticles through the interactions of rice protein (RP) or pea protein (PP) with chia mucilage (CM) to encapsulate hydrophobic compounds. Gum Arabic (GA) and type B gelatin (GE) were used as model materials. Optimal ratio and pH values for the mixtures were determined through macroscopic, turbidity and zeta potential analyses. The microparticles containing gum Arabic were smaller and more spherical, with mean diameters ranging from 22.03 to 35.20 μm, whereas those containing chia mucilage exhibited an irregular shape and diameters ranging from 33.49 to 53.10 μm. The yields (74.0 %-84.5 %) and encapsulation efficiency (around 99 %) for the microparticles containing chia mucilage were significantly higher than those of the formulations containing gum Arabic (yields of 18.4 %-40.1 %, and encapsulation efficiencies of 8.7 %-71.0 %). Based on the results, the most effective encapsulation system was identified PP:CM. All microparticles formed by chia mucilage and proteins have non-spherical characteristics and some roughness which can be interesting for applications in food or biological systems.