Preparation, interaction, and digestion of peanut oil body-based emulsion gels with xanthan gum and gallic acid

In this study, the effect of the concentration of xanthan gum (XG) on the network formation of peanut oil body (POB)-based emulsion gels in the presence of gallic acid (GA) were investigated. A POB-based emulsion gel (POBE-GA-XG) with an elastic solid structure was prepared, and analogous oil/water holding capacity, viscosity, and rheological behaviour were detected in POB-based emulsion gels stabilised with 0.8-1.6% XG. Additionally, POBE-GA-XG with a 1.6% XG concentration presented the maximum hardness (38.06 +/- 4.71 g), which was attributed to its dense and uniform network structure formed by interactions between the POB interface protein, GA, and XG. The fluorescence quenching and FTIR spectroscopy analyses revealed that GA increased the thickness of the interface layer through van der Waals forces and hydrogen bonds between the POB interface protein and GA. Then, the network became highly interconnected and more densely packed through hydrophobic interactions and hydrogen bonding formed through the interface protein and XG. Hydrogen bonding, electrostatic interactions, and van der Waals forces were the main driving forces between the POB interface protein, XG, and GA in the formation of the gel network. Finally, the digestion results revealed that POBE-GA-XG had the lowest free fatty acid (FFA) release rate and that the FFA release was fast diffusion. This study provided a new strategy for using POB in systems containing polysaccharides and polyphenols to construct emulsion gels as healthy solid fat substitutes.