title: Formation of positively charged microcapsules based on chitosan-lecithin interactions.
abstract: The formation of microcapsules which contain rosemary oil, is herewith described. The process is based on two steps: (a) formation of oil-in-water emulsions, by using lecithin as emulsifier, thus imparting negative charges on the oil droplets; (b) addition of a cationic biopolymer, chitosan, in conditions that favor the formation of an insoluble chitosan-lecithin complex. Zeta potential measurements revealed that addition of very low concentrations of chitosan to lecithin stabilized emulsions, led to reversal of charge. At a suitable pH range the chitosan precipitated around the oil droplets, forming positively charged microcapsules. The chitosan-lecithin insoluble complex is composed of a 1:1 molar ratio of the chitosan monomeric unit and lecithin, as evaluated by elementary analysis and turbidity measurements.
authors.affiliation: Casali Institute of Applied Chemistry, Hebrew University of Jerusalem, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Magdassi
authors.forename: U
authors.initials: U
authors.lastname: Bach
authors.forename: K Y
authors.initials: KY
authors.lastname: Mumcuoglu
mesh_terms: D002214:Capsules; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D006863:Hydrogen-Ion Concentration; D010713:Phosphatidylcholines / Q000737:chemistry*
chemical_list: D002214:Capsules; D010713:Phosphatidylcholines; D002686:Chitin; D048271:Chitosan