Properties of Xanthan Gum （I）
At present, xanthan gum is the best biological gum in the world with an integration of thickening, suspension, emulsification and stability. The number of pyruvic acid groups at the end of molecular side chain can have a great effect on its properties. Xanthan gum on one hand possesses the same general properties as long-chain polymers. On the other hand, it has more functional groups than the general polymers, so it displays some distinctive properties under certain conditions.
1. Suspension and emulsification properties
Xanthan gum possesses a favorable suspension property as for insoluble solids and oil drops. The molecules of xanthan gum solution can form a banded spiral co-polymer and a fragile network structure like gum, and consequently it can support the forms of solid particle, liquid drops and air bubbles, and displays a strong emulsion stability property and a favarable suspension capacity.
2. Preferable water-solubility
Xanthan gum can be quickly dissolved in water and thus possesses preferable water-solubility. It is soluble even in cold water so it saves you from complicated processes and uses conveniently. Due to its strong hydrophilicity, however, make sure to use it properly. For example, if it is directly mixed with a small amount of water and not uniformly stirred, the outer sphere absorbs water, expands into a micelle, prevents water from entering into the inner sphere and hinders its effects. Xanthan gum should be prepared into solutions for use in a correct process. Its dry powder should be greatly mixed with such auxiliary materials in dray powder as salt or sugar and then slowly add water that is being stirred.
3. Thickening property
Xanthan gum solution has the properties of low concentration and high viscosity (The viscosity of 1% solution equals to 100 times gelatin) and is a kind of efficient thickener.
Xanthan gum solution has high viscosity a static or low shear rate. On the contrary, its viscosity will sharply decrease at a high shear rate but the molecule structure won’t change. Furthermore, when the shearing action is removed, it will immediately restore to its original viscosity. The relation between viscosity and shearing action is absolutely plastic. The pseudoplastic property of xanthan gum is remarkable and plays a very important role in stabilizing suspension and emulsion.