Roles of polysaccharide charge and viscosity in soy protein-polysaccharide stabilized high internal phase emulsions...

Soy protein isolate (SPI)-polysaccharide-stabilized high internal phase emulsions (HIPEs) are promising fat alternatives for meat analogs. However, the distinct contributions of polysaccharide charge and viscosity to emulsion formation, stabilization and meat analog quality remain unclear. This study systematically investigated five polysaccharides with different charges and viscosities, namely cationic chitosan (CS), neutral locust bean gum (LBG) and guar gum (GG), and anionic xanthan gum (XG) and high methoxyl pectin (HP), in modulating SPI structure, HIPE performance, and plant-based patty quality. Results showed that polysaccharide charge dominated SPI-polysaccharide interactions and dictated SPI conformational remodeling. Neutral polysaccharides interacted with SPI through hydrogen bonding/hydrophobic interactions, significantly increasing the β-sheet content (GG: from 35.91% to 43.23%), and achieving the smallest initial droplet size through a high interfacial adsorption rate (GG: 6.81 μm). During emulsion stabilization and flavor retention, viscosity was the predominant factor. High-viscosity XG and GG excelled in inhibiting droplet aggregation, reducing gravitational separation, and maximizing volatile flavor retention under both heating and storage. At the application stage, viscosity predominantly influenced the hardness of patties. This study reveals the division of labor between polysaccharide charge and viscosity across different performance dimensions of HIPEs, guiding polysaccharide selection for tailoring HIPEs in meat analogs.