Synergistic effect of dextran and ergosterol: A venue for fabricating a water-in-oil pickering emulsion gel as a solid fat substitute in cream cheese

Abstract

The present study aimed to develop a Pickering emulsion gel by harnessing the synergistic effects of dextran (Dex) and ergosterol (Erg). In this context, Dex functioned as the internal aqueous phase structuring agent while Erg served as the emulsifying agent for the preparation of emulsion gel through a one-step homogenization method. By optimizing the water-oil ratio to 4:6, maintaining a Dex concentration of 1.0%, and achieving an Erg concentration of 3.5%, the resulting emulsion gel exhibited desirable characteristics, including minimal particle size, maximum zeta potential, and enhanced rheological properties. The incorporation of Dex resulted in a compact and uniform honeycomb structure, thereby reducing water mobility. The primary interactions between Dex and Erg were electrostatic, hydrogen bonding, and hydrophobic forces, which collectively contributed to a reduction in crystallinity. The three-dimensional network formed by Dex conferred advantageous stability to the emulsion gel. Moreover, the evaluation of the emulsion gel's delivery efficiency demonstrated its effectiveness in protecting both chlorogenic acid (CA) and Erg against adverse conditions, including a pH of 1.2, elevated temperature (90 °C), and UV-C radiation. Additionally, this system exhibited sustained-release characteristics for both CA and Erg, thereby enhancing their bioavailability and improving scavenging activities against DPPH and hydroxyl radicals. The emulsion gel also exhibited a lower release rate of free fatty acids (FFA). The cream cheese reformulated with 100% Pickering emulsion gel exhibited enhanced cohesiveness and greater viscoelastic properties than partial replacement. Overall, the present study successfully developed a water-in-oil emulsion gel, which holds significant potential for application in the production of low-fat food products.