title: Microencapsulation of bioactives in cross-linked alginate matrices by spray drying.
abstract: Microencapsulation of biomolecules, cells and chemicals is widely used in the food and pharmaceutical industries to improve stability, delivery and to control the release of encapsulated moieties. Among encapsulation matrices, alginate is preferred due to its low cost, biodegradability and biocompatibility. Current methods for producing stable alginate gels involve dropping alginate suspensions into divalent cation solutions. This procedure is difficult to scale-up and produces undesirably large alginate beads. In our novel encapsulation method, alginate gelation occurs during spray drying upon volatilisation of a base and rapid release of otherwise unavailable calcium ions. The resulting particles, with median particle sizes in the range 15-120 µm, are insoluble in solution. Cellulase and hemicellulase activities encapsulated by this method were not compromised during spray drying and remained stable over prolonged storage. The procedure described here offers a one-step alternative to other encapsulation methods that are costly and difficult to scale-up.
authors.affiliation: Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Santa-Maria
authors.forename: Herbert
authors.initials: H
authors.lastname: Scher
authors.forename: Tina
authors.initials: T
authors.lastname: Jeoh
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002480:Cellulase / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D003890:Desiccation; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods*; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D044367:Phase Transition; D012996:Solutions; D014783:Viscosity
chemical_list: D000464:Alginates; D003432:Cross-Linking Reagents; D005782:Gels; D006603:Hexuronic Acids; D012996:Solutions; D020723:Glucuronic Acid; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases