Preparation of nanoemulsions containing unsaturated fatty acid concentrate–chitosan capsules

Abstract

HypothesisFish 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. ExperimentsThe 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. FindingsThe 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 (332nm) 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).