Chia seed oil-in-water emulsions as potential delivery systems of ω-3 fatty acids

• O/W emulsion are suitable systems to protect chia oil against lipid oxidation.
• Homogenization pressure and NaCas concentration had a very significant effect on D [4, 3].
• The global stability of emulsions is mainly influenced by sodium caseinate content.
• The rheological properties is largely affected by sodium caseinate concentration.
• Chia O/W emulsions exhibited a good oxidative stability.

Chia oil can be incorporated into oil-in-water (O/W) emulsions as ω-3 fatty acid delivery systems in food matrices. Chia O/W emulsions varying in sodium caseinate (NaCas) concentration (2, 5 and 10% (wt/wt)), with and without 10% (wt/wt) lactose and using different homogenization pressures (400, 600 bar) were prepared, stored at 4 ± 1 °C and analyzed as a function of particle size, ζ-potential, rheological properties, backscattering profiles, peroxide and p-anisidine values. Droplet characteristics, rheology and stability of emulsions are influenced with different extent by the factors analyzed. All systems recorded negatively charged droplets and unimodal particle size distribution. Emulsions with 2 and 5% (wt/wt) NaCas presented a Newtonian fluid behavior. The former showed moderate stability to creaming, while the latter presented destabilization by flocculation and creaming few hours after preparation. Emulsions with 10% (wt/wt) NaCas showed a pseudoplastic fluid behavior and high stability by the rearrangement of the aggregates into a firm gel network. Chia O/W emulsions exhibited a good oxidative stability.