Fabrication of crosslinked spray dried alginate microparticles for encapsulation of bioactives

Abstract

Alginate based microencapsulation system are popular for nutrients encapsulation and have been extensively studied. In this study, crosslinked calcium alginate microparticles were successfully fabricated using a novel one-step spray drying method. The one step fabrication eliminates the need for multiple crosslinking and drying steps, as in traditional calcium alginate microparticles production. Different materials characterization techniques were used to identify and confirm the crosslinks between alginate and divalent Ca2+ ion. Next, the potential of these microparticles for applications in encapsulation and targeted release was investigated. A model protein, Bovine Serum Albumin (BSA) and carotenoid β- carotene, were successfully encapsulated into the microparticles. Release studies of bioactive-loaded crosslinked microparticles in simulated gastrointestinal fluids showed a slow release in simulated gastric environment and faster bioactive release in simulated intestinal environment. In addition, the particles were found to be stable in aqueous environments, preventing the leaching of the bioactives. The crosslinked alginate microparticles have the potential to provide numerous solutions in various industries e.g., protection against leaching in the aquaculture industry and targeted oral release in the food industry, to name a few.