The Role of Yeast Dietary Fiber-Derived Proteins and Polysaccharides in Emulsion Stabilization: Interfacial Mechanisms and Stabilizing Effects

Abstract

This study evaluated the structural characteristics and interfacial behavior of proteins (PR) and polysaccharides (PL) isolated from yeast dietary fiber, as well as their complexes (PL/PR), while elucidating their impact on emulsion stability. The results showed that spherical PR exhibited a rapid adsorption rate and strong adsorption capacity, forming the most viscoelastic (11.06 mN/m) interfacial layer. PL, with its network structure, had relatively high viscoelasticity (10.72 mN/m) but the weakest adsorption capacity. For PL/PR, PR was initially adsorbed onto the oil droplet surface, followed by the arrangement of PL at the oil-water interface, resulting in the lowest viscoelastic adsorption layer (9.96 mN/m). As stabilizer concentration increased, the dominant factor influencing emulsion stability shifted from film viscoelasticity to the stabilizer’s adsorption capacity. Besides, at a high PR concentration (6%), its strong adsorption increased the density and rigidity of the interfacial film, thereby weakening the emulsion's stress resistance, leading to emulsion destabilization.

Keywords: Yeast dietary fiber, interfacial rheology, Interface behaviors, Quartz crystal microbalance with dissipation, Pickering Emulsion