Salt reduction in semi-solid food gel via inhomogeneous distribution of sodium-containing coacervate: Effect of gum arabic

High salt intake is the leading dietary risk factor for death from noncommunicable diseases in the world. Some solid and semi-solid gelled foods, such as bread, sausage and cheese, are among the saltiest in the food category. In this study, we develop a simple and scalable method for the preparation of semi-solid food with an inhomogeneous salt distribution by dispersing sodium-containing soy protein/gum arabic coacervates into the food gels. The sensory analysis reveals an enhanced saltiness of these food gels allowing a reduction in the sodium content of 30%, while maintaining the taste and texture qualities. From the result of the kinetic release of sodium during mastication, we conclude that the enhanced saltiness is attributed not only to the sensory contrast structure but also to a faster sodium release. Quartz crystal microbalance with dissipation (QCM-D) is used to measure the binding affinity of Na+ and gum arabic (GA) with the mucin layer for the first time, showing that GA induces the swelling of the mucin layer, and the GA that is screened by salt exhibits the mucopenetration ability. This result is helpful to understand the enhanced saltiness and the acceleration of sodium diffusion through the inhomogeneous spatial distribution of protein/gum arabic coacervates.