Impact of dispersion conditions and coacervation on fibril formation in gellan gum-potato protein mixtures

Abstract

The development of plant-based meat analogs as sustainable alternatives to traditional meat products is a major focus of the modern food industry. Meat-like structures and textures can be fabricated from protein-polysaccharide mixtures using soft matter physics approaches. In this study, we investigated the effects of gellan gum dissolution properties on the fiber formation and textural properties of potato protein-gellan gum composites. We hypothesized that the fibrous structures naturally formed by powdered gellan gum when it is dispersed in water may be useful for creating meat analogs. Zeta-potential measurements showed that cationic potato protein and anionic gellan gum formed electrostatic complexes. In the presence of excess protein, complexation of gellan gum and potato protein resulted in the formation of fibrous structures. Fiber formation and thermal gelation of the protein-polysaccharide composites depended on whether salt (100 mM NaCl) was added, and whether it was added before or after the gellan gum. The shear modulus of heat-set composite gels was higher in the presence of salt than in its absence, which was the opposite to what was observed for pure gellan gum gels. Moreover, adding salt before the gellan gum led to stronger heat set gels than adding it after the gellan gum. These effects were mainly attributed to the ability of the mineral ions to screen the electrostatic interactions between the biopolymer molecules, thereby altering their packing behavior. Our findings suggest that controlling the dispersion and coacervation of gellan gum and potato protein can be used to create fibrous structures, which may facilitate the development of plant-based meat products with improved textural attributes.