Ultrasound mediated flaxseed oil microcapsule: effect of ternary wall material (Arabic gum-Whey Protein Concentrate-Maltodextrin) on the characterization, in vitro release behaviour and storage stability

Abstract

The primary objective of the present study was aimed at exploring the effect of ultrasound on the encapsulation potential of a ternary blend of wall materials (Arabic gum-Whey Protein Concentrates-Maltodextrin; GA:WPC:MD) for effective 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 was observed, exhibited pseudoplastic behavior. Microcapsules were obtained with highest encapsulation rates of 90.27% with 4 minutes of sonication treatment with GA:WPC:MD 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 the formation of uniform spherical and continuous wall formation. The microcapsules’ oxidative stability was observed to be significantly higher even after 56 days of storage and accelerated oxidative stability rates were 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 favored after sequential exposure to intestinal conditions. Therefore outcomes of the study demonstrated the important implications in designing of encapsulation systems for lipid soluble bioactives for their effective and targeted, controlled delivery in various food products.