The use of arabic gum, maltodextrin and surfactants in the microencapsulation of phytosterols by spray drying

The addition of phytosterols in aqueous-based food matrices is challenging because of their poor physicochemical properties (non-water soluble and hydrophobic powder). By using spray drying, phytosterols microparticles were formulated and developed in this work. Arabic gum, maltodextrin and one of two different surfactants were thoroughly studied as wall materials. Increasing concentrations of Tween 20 (T20) or sodium lauryl sulfate (SDS), from 0.1 to 2.65% w/v, were evaluated. The feed suspension characteristics (viscosity, interfacial properties and particle size distribution), process yield (PY), encapsulation efficiency (EE), phytosterols retention (R) and size of the microparticles were analyzed. The presence of surfactants in the suspension to be spray dried has significant effects on the studied responses. T20 led to process yields around 65% (2% w/v surfactant concentration). On the other hand, the microparticles obtained using 2% w/v of SDS were the best in terms of EE (about 50%), R (close to 40%) and particle size (5.89μm), being the PY acceptable (almost 55%). According to the open literature, which indicates that average particle sizes lower than 25μm favor the phytosterols bioavailability, the microparticles obtained in this work are promising for phytosterols delivery.