Development and characterization of chitosan/gelatin electrosprayed microparticles as food grade delivery vehicles for anthocyanin extracts

This work reports on the development of electrosprayed chitosan/gelatin microparticles for encapsulation purposes. Initially, the effects of the chitosan molecular weight (Mw), biopolymers and solvent composition on solution properties and capsule formation were investigated. Results demonstrated that the sprayability of the blend solutions was mainly determined by a critical range of solids content, which was needed for chain entanglement and subsequent capsule formation, and by their rheological properties. SAXS experiments from selected electrospraying solutions showed that clustered networks between both biopolymers were formed due to the electrostatic interactions between the positively charged amino groups in chitosan and negatively charged amino acid residues in gelatin. As a model bioactive extract, an anthocyanin-rich black carrot extract (BCE) was loaded into selected chitosan/gelatin electrosprayed structures and the encapsulation efficiency and release into two food simulants (ethanol 10% and acetic acid 3%) was evaluated. Faster and greater release was observed in the acetic acid medium as expected and the results showed that the main factor affecting the bioactive release was the blend composition, i.e. increasing the chitosan content of the formulations limited BCE release. (C) 2017 Elsevier Ltd. All rights reserved.