Characteristics and performance of Xanthan Gum

Xanthan gum, also known as Hansheng gum, is a pool of extracellular microorganisms produced by the fermentation of sugars by Pseudomonas aeruginosa. Because of its special macromolecular structure and colloidal properties, it has a variety of functions and can be widely used in various fields of the national economy as an emulsifier, stabilizer, gel thickener, sizing agent, film forming agent, etc.

Xanthan gum is currently the most excellent biological gum in the world that integrates thickening, suspension, emulsification, and stability. It is a light yellow to white flowable powder with a slight odor. Easy to dissolve in cold and hot water, neutral solution, resistant to freezing and thawing, insoluble in ethanol. Disperse and emulsify in water to form a stable hydrophilic viscous colloid.

Characteristics and performance

1. Suspension and emulsification properties

Xanthan gum has a good suspension effect on insoluble solids and oil droplets. Xanthan gum sol molecules can form super bonded helical copolymers, forming fragile gel like network structures, which can support the morphology of solid particles, droplets, and bubbles, demonstrating strong emulsification stability and high suspension ability.

2. Good water solubility

Xanthan gum can quickly dissolve in water and has good water solubility. It can also dissolve in cold water, eliminating the complicated processing process and making it convenient to use. However, due to its strong hydrophilicity, if water is added directly without sufficient stirring, the outer layer will absorb water and expand into micelles, which will prevent water from entering the inner layer and affect its effectiveness. 

3. Thickening properties

Xanthan gum solution has the characteristic of low concentration and high viscosity (the viscosity of 1% aqueous solution is 100 times that of gelatin), making it an efficient thickener.

4. Pseudoplasticity

Xanthan gum aqueous solution exhibits high viscosity under static or low shear conditions, and exhibits a sharp decrease in viscosity under high shear conditions, but the molecular structure remains unchanged. When the shear force is eliminated, the original viscosity is immediately restored. The relationship between shear force and viscosity is completely plastic. Xanthan gum has a very prominent pseudoplasticity, which is extremely effective in stabilizing suspensions and emulsions.

5. Stability to heat

The viscosity of xanthan gum solution does not change significantly with temperature changes. Generally, polysaccharides undergo viscosity changes due to heating, but the viscosity of xanthan gum aqueous solution remains almost unchanged between 10-80 ℃. Even low concentration aqueous solutions exhibit stable high viscosity over a wide temperature range. 1% xanthan gum solution (containing 1% potassium chloride) was heated from 25 ℃ to 120 ℃. Its viscosity only decreased by 3%.

6. Stability to acidity and alkalinity

Xanthan gum solution is very stable to acids and bases, and its viscosity is not affected between pH 5-10. There is a slight change in viscosity when pH is less than 4 and greater than 11. Within the range of PH3-11, the maximum viscosity is within 10% of the minimum value. Xanthan gum can be dissolved in various acid solutions. These Xanthan gum acid solutions are relatively stable at room temperature, and the quality of the product remains unchanged for several months. Xanthan gum can also be soluble in sodium hydroxide solution and has thickening properties. The resulting solution is very stable at room temperature. Xanthan gum can be degraded by strong oxidants such as perchloric acid and persulfuric acid, and the degradation accelerates with increasing temperature.

7. Stability of salt

Xanthan gum solution can be mixed with many salt solutions (potassium, sodium, calcium, magnesium, etc.), and its viscosity is not affected. Under high salt concentration conditions, even in saturated salt solutions, its solubility is maintained without precipitation and flocculation, and its viscosity is almost unaffected.

8. Stability of enzymatic hydrolysis reaction

The stable double helix structure of xanthan gum endows it with strong antioxidant and anti enzymatic abilities, and many enzymes such as proteases, amylases, cellulases, and hemicellulases cannot degrade xanthan gum.