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

Chia oil can be incorporated into oil-in-water (O/W) emulsions as omega-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 degrees C and analyzed as a function of particle size, zeta-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. (C) 2015 Elsevier Ltd. All rights reserved.