Preparation, characterization and in vitro digestive behaviors of emulsions synergistically stabilized by γ-cyclodextrin/sodium caseinate/alginate

Developing natural, safe, and biocompatible emulsion stabilizers for highly stable emulsions remains a difficult challenge. In this study, stable nano-scale emulsions were prepared using γ-cyclodextrin (γ-CD), sodium caseinate (SC), and alginate (Alg) as emulsifiers. The synergistic stabilization of γ-CD/SC/Alg enabled the emulsions to remain stable even under high-acidic (pH 3.0), high-alkaline (pH 11.0) and high temperature (90 °C) conditions. The improved stability at acidic conditions was attributed to the positive impact of Alg. Additionally, the rheological measurements showed that the emulsions exhibited elastic gel networks and a more stable emulsion structure was formed with the increasing addition of γ-CD. Finally, the gastrointestinal behavior of the emulsions was studied using a standardized INFOGEST method. Results showed that most of the oil were digested and absorbed in the small intestine, and the bioaccessibility of curcumin was high. This work provided a new solution to prepare stable emulsions which could be used as dairy products or desirable food delivery systems for hydrophobic bioactive agents.