Water-dispersible xanthan gum containing composition

#The present invention relates to a particulate composition containing xanthan gum that is readily dispersible in water. Another aspect of the invention concerns a highly viscous aqueous dispersion of discrete swollen particles that contains xanthan gum. Yet another aspect of the invention relates to a process for the manufacture of a readily water dispersible particulate composition containing xanthan gum.

#The fermentative production of the water-soluble polysaccharide xanthan gum by the action of Xanthomonas bacteria is well known. Xanthomonas hydrophilic colloid (“xanthan”) is an exocellular heteropolysaccharide. The heteropolysaccharide has a backbone chain of (1→4)β-glucose residues substituted by short, lateral chains linked to alternate monomeric residues of the main chain. Xanthan has a wide variety of industrial applications including use as a thickener, a stabilizing agent and a suspending agent, especially in foods. Furthermore, xanthan is used in oil well drilling muds and as a viscosity control additive in secondary recovery of petroleum by water flooding. Xanthan can also be used in cosmetic preparations, pharmaceutical delivery systems and similar compositions.

#Xanthan is produced on an industrial scale by aerobic submerged fermentation of a bacterium of the genus Xanthomonas. The fermentation medium contains carbohydrate (such as sugar), trace elements and other nutrients. Once fermentation is complete, the resulting fermentation broth is heat-treated. Following heat-treatment, the xanthan is recovered by alcohol precipitation.

#FIG. 1: Shows the Temperature and Viscosity Profile of Particulate Xanthan in Rapid Viscosity Analyser.

#FIG. 2: Shows the Viscosity and Temperature Profile of 1:1 Coextruded Blends of Xanthan with other Biopolymers.

#Accordingly, one aspect of the present invention relates to a readily water-dispersible particulate composition comprising by weight of dry matter at least 10% of xanthan gum and not more than 60% of starch, said composition being characterised in that the xanthan gum present in the composition can be dispersed completely within 2 minutes in distilled water of 25° C. at a concentration of 0.7% based on the dry weight of xanthan using a method comprising introducing 500 ml of distilled water to a beaker of 1000 ml, stirring with a stirrer with a four bladed impeller with a diameter of 5 cm, operating at fixed rate of 300 rpm and adding the xanthan containing particulate composition to give a concentration of 0.7% based on the dry weight of xanthan.

#The term “particulate” as used herein shall be interpreted broadly and held to comprise particles of any porosity and or density. According to a preferred embodiment, the present particulate composition is a free flowing composition. The present particulate composition may suitably be composed of particles of homogenous composition as well as of particles in the form of e.g. agglomerates or encapsulates. Typically, the particles in the present composition exhibit a volume weighted average particle size in the range of 10-1000 μm.

#The term “xanthan” or “xanthan gum” as used herein means the extracellularly produced heteropolysaccharide made by a bacterium of the genus Xanthomonas. Examples of Xanthomonas species that may suitably be used to produce xanthan gum include Xanthomonas campestris, Xanthomonas begonias, Xanthomonas malvaceraum, Xanthomonas carotae, Xanthomonas incanae, Xanthomonas phaseoli, Xanthomonas vesicatoria, Xanthomonas papavericola, Xanthomonas translucens, Xanthomonas vesicatoria, and Xanthomonas hedrae.