Suitability in the microencapsulation of fish oil and in vitro bioaccessibility of omega-3 fatty acids

Abstract

Due to the bioactivity of omega-3 fatty acids, mainly eicosapentaenoic and docosahexaenoic fatty acids (EPA and DHA, respectively), and their high susceptibility to oxidation, the microencapsulation of sources rich in these bioactive compounds is being applied as a stabilization strategy, being required to adjust formulation variables of the process to get microcapsules with desirable characteristics. Thus, the objective of this study was to stablish most appropriate chitosan concentration and homogenization technique of chitosan-maltodextrin emulsions of fish oil to achieve suitable microcapsules of omega-3 fatty acids with high quality characteristics and in vitro bioaccessibility of EPA and DHA. For that, spray-dried microcapsules from fish oil emulsions with different chitosan concentration (1%, 1.25% and 1.5%) and homogenized with high-pressures or ultrasounds were elaborated. In general, all batches showed appropriate quality characteristics in emulsions and microcapsules. However, the studied variables (chitosan concentration and homogenization techniques) significantly influenced most of the evaluated properties (pH, creaming index, viscosity and density of emulsions; efficiency, lipid oxidation, particle size, morphology, and EPA and DHA quantity and release during in vitro digestion in microcapsules), being noted that the use of 1.5% chitosan and homogenization by ultrasounds enhanced the emulsion stability and efficiency, oxidation stability, particle size, and concentration and in vitro bioaccessibility of EPA and DHA in microcapsules. Then, these conditions may be stablished to get suitable microcapsules of omega-3 fatty acids with high quality characteristics and in vitro bioaccessibility of EPA and DHA.