title: Preparation of nanoemulsions containing unsaturated fatty acid concentrate-chitosan capsules.
abstract: OBJECTIVE
  Fish oil is rich in unsaturated fatty acids (ω-3), which are highly susceptible to oxidative degradation. The use of encapsulation process to retard the fatty acid oxidation is an interesting alternative. In this work, nanoemulsions containing capsules of unsaturated fatty acids concentrate (UFAC) using chitosan as wall material were prepared and characterized.
  
  
  METHODS
  The UFAC were obtained from carp viscera and chitosan was obtained from shrimp wastes. The nanocapsules were prepared by the emulsion method. Four formulations were tested, using different combinations of chitosan concentration and homogenization times. In the more suitable conditions, the emulsion was freeze-dried to obtain a microstructure with capacity to increase the capsules stability.
  
  
  RESULTS
  The results showed that the nanocapsules presented a spherical shape. The use of low wall material concentration and high homogenization time provided nanocapsules with smallest size (332 nm) and lowest polydispersity index (0.214). The microstructure obtained by freeze drying was irregular and porous. The peroxide values demonstrated that the microstructure was able to protect the UFAC regarding to primary oxidation. The encapsulation efficiency was 74.1%, showing that chitosan has potential to be used as encapsulating agent for unsaturated fatty acid concentrate (UFAC).
authors.affiliation: Unit Operation Laboratory, School of Chemistry and Food, Federal University of Rio Grande, FURG, Italia Avenue, km 08, 96203-900 Rio Grande, RS, Brazil. Electronic address: nessafurg@gmail.com.
authors.forename: V M
authors.initials: VM
authors.lastname: Esquerdo
authors.affiliation: Environmental Processes Laboratory, Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil. Electronic address: guilherme_dotto@yahoo.com.br.
authors.forename: G L
authors.initials: GL
authors.lastname: Dotto
authors.affiliation: Unit Operation Laboratory, School of Chemistry and Food, Federal University of Rio Grande, FURG, Italia Avenue, km 08, 96203-900 Rio Grande, RS, Brazil. Electronic address: dqmpinto@furg.br.
authors.forename: L A A
authors.initials: LAA
authors.lastname: Pinto
mesh_terms: D000818:Animals; D033202:Anostraca; D002347:Carps; D048271:Chitosan / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000737:chemistry; D005612:Freeze Drying; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010316:Particle Size
chemical_list: D004655:Emulsions; D015525:Fatty Acids, Omega-3; D053769:Nanocapsules; D048271:Chitosan
keywords: Chitosan; Encapsulation; Fish oil; Nanoemulsion; Unsaturated fatty acid concentrate