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

• Phytosterols were successfully microencapsulated by spray drying.
• The higher HLB surfactant enhanced the core/wall materials affinity.
• Process performance and product quality were correlated with the feed properties.
• Promising encapsulation efficiency, process yield and particle sizes were obtained.

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 (5.89 μm), being the PY acceptable (almost 55%). According to the open literature, which indicates that average particle sizes lower than 25 μm favor the phytosterols bioavailability, the microparticles obtained in this work are promising for phytosterols delivery.

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