Multilayer microencapsulation of chia seed oil by spray-drying using electrostatic deposition technology

A multilayer microencapsulation process was carried out to protect and deliver chia oil, which presents high nutritional value but also a high susceptibility to lipid oxidation. A high-pressure homogenization was performed with deoiled or hydrolyzed sunflower lecithins (pH 5) to obtain the primary emulsion. The secondary and ter-tiary layers were deposited, applying the layer-by-layer technique with the addition of chitosan and chia mucilage, respectively. After spray-drying these emulsions, the corresponding microcapsules were obtained and the influence of the types of lecithin (deoiled or hydrolyzed) and microcapsule (mono or multilayered) were studied. The zeta-potential evidenced the electrostatic deposition of the layers through the inversion of the electric charge. Microcapsules presented high microencapsulation efficiency (84-99%) and low moisture content and water activity levels. Most microparticles exhibited whitish and light color, spherical shapes, with continuous and slightly rough walls. The powder dispersibility was compatible with instant foods. All the microcapsules presented low oxidation levels after storage, especially the three-layer systems. This information suggests that multilayer systems can contribute by providing high stability against the oxidative deterioration of functional lipid components present in chia oil.

Automated summary

The multilayer microencapsulation process successfully protected and delivered chia oil, enhancing its stability and preventing oxidation. The microcapsules showed high efficiency and low moisture content, with uniform particle shape, suitable for instant foods.