Effect of ultrasound on the encapsulation potential of a ternary blend of wall materials for protection of flaxseed oil

The primary objective of the present study was to explore the effect of ultrasound on the encapsulation potential of a ternary blend of wall materials (Whey Protein Concentrates: Maltodextrin: Gum Arabic; WPC: MD: GA) for adequate protection of flaxseed oil. Combined effects of sonication treatment time and variable composition of wall materials on the emulsion properties (droplet size, Polydispersity Index and Zeta Potential and viscosity) and subsequent spray-dried microcapsules of flaxseed oil were investigated. The best-formulated emulsion, with average droplet sizes of 406.28 nm, exhibited pseudoplastic behaviour. Microcapsules were obtained with the highest encapsulation rates of 90.27% with 4 min of sonication treatment with WPC: MD: GA present in ratio of 0.20:0.50:1.5. The microcapsules' flow properties were also found to be optimum. Morphological assessment of microcapsules indicated uniform spherical and continuous wall formation. The microcapsules' oxidative stability was significantly higher even after 56 days of storage, and accelerated oxidative stability rates also increased manifolds after encapsulation. In vitro gastrointestinal digestion results revealed that designed conditions retarded release under gastric conditions, with less than 10% release of oil. However, higher (56% release) bioaccessibility rates were favoured after sequential exposure to intestinal conditions. Therefore, the study outcomes demonstrated the critical implications of designing encapsulation systems for lipid-soluble bioactive for their practical and targeted, controlled delivery in various food products.