Development and Optimization of Novel Encapsulation Structures of Interest in Functional Foods Through Electrospraying

The aim of this work was to establish strategies for the development of electrosprayed encapsulation structures, of interest in food applications, based on aqueous hydrocolloid dispersions. Specifically, various polysaccharides and two different proteins were evaluated for capsule formation. To this aim, the hydrocolloid dispersion properties were analysed and compared with the solution properties of two polymers readily spinnable in water (polyvinyl alcohol (PVOH) and polyethylene oxide (PEO)). Increasing the hydrocolloid concentration to promote chain entanglements resulted in a valid strategy only for a few matrices (related to their greater Mw). As alternative strategies to improve the physical properties and, thus, the sprayability of the dispersions, addition of gums and surfactants to modify their viscosity and surface tension, respectively, was evaluated. Moreover, denaturation of proteins was also carried out in order to investigate the effect of this treatment on the electrospraying process and on capsule formation. Results showed that the incorporation of some of these molecules, as well as protein denaturation, significantly changed the physical properties, allowing the development of encapsulation structures from all the hydrocolloids assayed. The morphology of the structures obtained was characterized, and the molecular organization of some of the capsules was studied and related to the electrosprayability and capsules morphology.