Interactions between polysaccharides and surfactants in aqueous solutions are the topic of this chapter. These components are often found in foods as well as in other systems like cosmetics, paints, detergents, textiles and many more. Therefore, investigation of the interactions between polysaccharides and surfactants has a great practical and fundamental interest. For the sake of clarity, we have divided the discussion into three sections: polysaccharides-nonionic surfactants; polysaccharidescationic surfactants and polysaccharides-anionic surfactants. The behavior of polysaccharide-surfactant systems depends on many factors, which mainly include: 1) physical properties of both components, like molecular weight, degree of branching, number, and type of charge groups, backbone rigidity, 2) polysaccharide concentrations, 3) surfactant type; ionic or nonionic, polar head, chain length, and concentration. Environmental conditions like pH, ionic strength and presence of salt can partially screen electrostatic interactions, and there are also other factors needed to be considered when working with this type of mixtures. All these factors make it difficult to predict the behavior of polysaccharide-surfactant mixtures. However, in almost all cases, addition of surfactant modifies the behavior of the polysaccharide, regardless of polysaccharide and surfactant, but the modification is particular to the chemical nature of the polysaccharide and surfactant.
Keywords: Alginate, Biopolymers, Carboxymethylcellulose, Carrageenan, Chitosan, Electrostatic interactions, Emulsion, Hydrophobic interactions, Micelles, Polyelectrolyte, Polysaccharide, Surface tension, Surfactant.