Effect of emulsification techniques on the distribution of components on the surface of microparticles obtained by spray drying

Abstract

The number of studies on the surface composition of microparticles obtained by spray drying has increased due to the interest in understanding the relationship between the characteristics of these microparticles and the oxidation stability of encapsulated bioactive compounds. The aim of this study was to evaluate the effect of emulsification techniques on the distribution of components on the surface, microstructure, and physicochemical properties of encapsulated β-carotene microparticles obtained by spray drying. Emulsions created by microfluidization and observed by XPS showed a greater presence (11.35–16.82%) of hydrophilic amino acids (histidine, glycine, serine, threonine) on the surface. Emulsions obtained by rotor/stator system exhibited low encapsulation efficiency (9.1–46.0%), and the microparticles presented a high number of surface irregularities (shrinkage and dents) compared to the microfluidization samples. In contrast, emulsions obtained by microfluidization showed shorter wetting (12.37–14.47 min) and solubility times (25.66–30.22 min), attributed to the percentage of protein on the surface of microparticles. The characteristics of the microparticles provided by the microfluidizer could help in the design of fast-hydration and dispersion powder products by spray drying.