ABSTRACT
The physical properties of gellan gum are strongly influenced by the presence and level of acyl group side chains. Dextran, xanthan gum, and gellan gum are all polysaccharides produced commercially by bacterial fermentation. A pure sodium salt of deacylated gellan gum will dissolve in deionized water at room temperature. The presence of divalent salts in the commercially available forms of deacylated gellan gum inhibit the gum’s hydration. Hydrated in cold water with the aid of sequestrants, gellan gum solutions are highly viscous. Deacylated gellan gum is commercially available in both clarified and unclarified forms. The texture of deacylated gellan gum gels is commonly described as firm and brittle. Gels occur when hot gellan gum solutions are allowed to cool and set under quiescent conditions. Gellan gum solutions can be cast and dried into a film. The gellan solution can be prepared hot or cold with little difference in film tensile strength.
