Design of fish oil-in-water nanoemulsion by microfluidization

- Fish oil nanoemulsions were produced by microfluidization.
- Pressure and number of passes of microfluidization reduce the particle size.
- Mesquite gum stabilizes nanoemulsions through steric and electrostatic repulsion.
- Mesquite gum is a potential emulsifier in food nanoemulsions.

In the last years, the consumption of polyunsaturated fatty acids (PUFAs) has been promoted due to the prevention and treatment of different diseases. When these are marketed as emulsions, their therapeutic efficacy depends on their charge and size. Microfluidization is an emerging technology able to produce smaller droplet sizes. The aim of this study was to evaluate the capacity of mesquite gum to produce fish oil emulsion by microfluidization as a function of pressure and number of passes. Emulsions were produced according to a two factor, three level with two central points: pressure from 34.5 to 206.8 MPa and 1 to 5 passes. The zeta potential and droplet size distributions were evaluated using electrophoretic and dynamic light scattering equipment, respectively. Coarse emulsion produced by high-shear mixer shows a droplet size up to 1.5 μm, while microfluidization process produce smaller droplet size (≥ 200 nm). Also, zeta potential values increased around − 30 ± 2 mV. The optimal conditions were estimated at 144 MPa and two passes of microfluidization. Nanoemulsions with an average droplet size around 200 nm could be used to improve their absorption in the digestive tract.