Development of a soy protein isolate–carrageenan–quercetagetin non-covalent complex for the stabilization of β-carotene emulsions

The current study investigated the application of a soy protein isolate (SPI), κ-carrageenan (CG) and quercetagetin (Qut) non-covalent complex in stabilizing β-carotene emulsions. The ternary complex was formed through a mild mixing and incubation process. FTIR measurement indicated the formation of hydrogen bonds in the non-covalent complex. SPI-CG and SPI-CG-Qut complexes had a much smaller particle size when redispersed in water after spray drying, compared to those in the original dispersions (p < 0.05). Dynamic light scattering analysis revealed that the emulsion stabilized with the ternary complex had a bigger particle size, higher surface charge, and improved creaming stability compared to those stabilized with SPI or SPI-Qut (p < 0.05). The ternary complex allowed less degradation of β-carotene in the emulsions when exposed to light or thermally treated at 37 °C or 55 °C. Therefore, the SPI-CG-Qut non-covalent complex might work as a novel ingredient in designing delivery systems for β-carotene.