Hydrocolloids

Xanthan gum

Xanthan gum is a natural, high molecular weight polysaccharide produced by the microorganism xanthomonas campestris by microbial fermentation. It is highly versatile in personal care as it is resistant to enzymatic degradation, extremely stable over a wide temperature and pH range and also in high concentrations of alcohol and salt, which makes it suitable for a variety of applications. Xanthan gum is primarily used as a thickener but is also the most efficient stabilizer for suspensions, emulsions, foams and solid particles in water-based formulations.

Brand name

• SATIAXANE™ CS

Cargill’s products are available in various degrees of granulation to suit the applications for which they are intended. A clear version of xanthan gum is also available.

Cargill can supply grades of xanthan gum that meet the specifications of Ph.Eur. and USP/NF, when tested accordingly.

Applications

Due to the unique rheological and synergetic properties of its aqueous solutions, xanthan gum is used in a large number of applications, as a suspending agent, an emulsion and foam stabilizer, a foam enhancer, or as a thickener.

Skin care - lotions, creams, face masks and packs
Sun care - suntan lotions and sunscreens
Bath and shower care - shower gels and body washes
Color cosmetics - make-up, mascaras and eyeliners
Hair care - shampoos and conditioners
Oral care - toothpaste - xanthan gum offers superior water binding and excellent formulation stand up in a broad range of toothpaste formulations. It can be used as well as a stand alone binder or in combination with other commonly used binders
Shaving foams

Functionalities

Cold water soluble
The presence of anionic side chains on the xanthan gum molecules enhances hydration and makes xanthan gum soluble in cold as well as hot water.

Viscosity control
The viscosity of xanthan gum is stable at low pH values and at high temperatures for a long period of time, whereas other hydrocolloids lose their viscosity under the same conditions.

Temperature and acid stability
Solutions of xanthan gum are not generally affected by changes in pH or temperature and will dissolve in most acids or bases.

Salt tolerance
The viscosity of xanthan gum is not affected by the addition of large amounts of salt and demonstrates excellent compatibility in the presence of anionic, amphoteric and non-ionic surfactants. When tested in a 250 /l NaCl brine, only a slight increase in viscosity could be observed.

Freeze/thaw stability
Due to its water binding capacity, xanthan gum solutions exhibit good freeze/thaw stability.

Compatibility with other hydrocolloids
Xanthan gum has a synergistic increase in viscosity or gel strength when used with galactomannans, particularly locust bean gum (gel formation) and guar gum (higher viscosity).

Shear-thinning pseudoplastic rheology
The high viscosity associated with xanthan gum solutions at low shear rates enables products to keep particles suspended or prevent oil droplets from coalescing. Because the viscosity drops when shear is applied, the end consumer products can be easily scooped, poured, or squeezed from its container. Once the force is removed, the solutions regain their initial viscosity almost immediately.

Electrolyte tolerant
Resistant to enzymatic degradation
Forms gels
Forms fluid gels with unique suspension properties
Sparkling clarity
Process flexibility and tolerance
Excellent suspension for insoluble solids and oil droplets
Effective at low concentrations
Thickening agent
Shear reversible behavior
Excellent emulsion and foam stabilization
Excellent stability

Chemistry

Xanthan gum is an hetero-polysaccharide of high molecular weight. Its main chain is constituted of glucose units. The side chain is a trisaccharide, consisting of alpha-D-mannose, which contains an acetyl group, beta-D-glucuronic acid, and a terminal beta-D-mannose unit linked with a pyruvate group.

These side chains represent about 60% of the molecule and give xanthan gum many of its unique properties.