EFFECT OF AQUEOUS PHASE COMPOSITION ON THE PHYSICOCHEMICAL STABILITY OF CHIA O/W EMULSIONS

JULIO, LUCIANA M.; IXTAINA, VANESA Y.; WAGNER, JORGE R.; NOLASCO, SUSANA M.; TOMÁS, MABEL C.

Olrando, Florida, USA

Congreso; 106th AOCS Annual Meeting and Industry Showcases; 2015

American Oil Chemists' Society

The effect of different aqueous phase composition on the stability of chia O/W emulsions was evaluated. O/W emulsions were prepared by homogenizing 10 wt% chia oil with 90% wt aqueous solution (600 bar), stored ~1 month at 4.0±0.5°C. Six formulations were prepared with sodium caseinate (NaCas) (10% wt/wt) and a chia protein-rich fraction (PRF) (2% wt/wt) as emulsifiers, lactose or maltodextrin (10% wt/wt) and presence or absence of chia mucilage (0.2% wt/wt). Stability of emulsions was evaluated by the evolution of backscattering (BS) profiles, ζ-potential, apparent viscosity, particle size distribution, mean diameter (D[4,3]) and peroxide value (PV). The particle size distribution was monomodal for NaCas-Lac emulsions with and without mucilage added and bimodal for the rest of the systems. The initial D[4,3] was 0.3-0.4 µm and 17-18 µm for NaCas and PRF-based emulsions, respectively. Increases on particle size of NaCas-based emulsions during storage were observed. PRF-based emulsions destabilized by creaming a few minutes after their preparation, while BS profiles of NaCas-stabilized emulsions did not exhibit important changes during the storage. The apparent viscosity was NaCas-Mltdx˃NaCas-Lac˃PRF-Mltdx, which increased with chia mucilage addition. ζ-potential was -30 mV and -20 mV for emulsions with NaCas and PRF, respectively. The different systems recorded low PV levels.