Xanthan gum, composition, properties & applications

Introduction to Xanthan gum

Xanthan gum, also known as Hansen gum, is a widely used microbial exopolysaccharide produced by Xanthomnas campestris using carbohydrates as the main raw material (such as corn starch) through fermentation engineering. It has unique rheology, good water solubility, stability to heat and acid and base, and good compatibility with a variety of salts. As a thickener, suspending agent, emulsifier, and stabilizer, it can be widely used in more than 20 industries such as food, petroleum, and medicine. It is currently the largest and most widely used microbial polysaccharide in the world.

Properties of xanthan gum

Xanthan gum is a light yellow to white flowable powder with a slight odor. Easily soluble in cold and hot water, neutral solution, resistant to freezing and thawing, insoluble in ethanol. Disperse and emulsify in contact with water into a stable hydrophilic viscous colloid.

Performance characteristics:

Xanthan gum is currently the most superior biological gum in the world for thickening, suspending, emulsifying and stabilizing. The number of pyruvate groups at the end of the molecular side chain of xanthan gum has a great impact on its performance. Xanthan gum has the general properties of long-chain polymers, but it contains more functional groups than general polymers and will show unique properties under specific conditions. Its conformation in aqueous solution is diverse, and it exhibits different properties under different conditions.

Suspension and emulsification

Xanthan gum has a good suspension effect on insoluble solids and oil droplets. Xanthan sol molecules can form helical copolymers with super-binding bands, forming fragile gel-like network structures, so they can support the morphology of solid particles, droplets and bubbles, showing strong emulsion stabilization and high suspension ability.

Good water solubility

Xanthan gum can dissolve quickly in water and has good water solubility. Especially in cold water, it can also dissolve, which can save the complicated processing process and is easy to use. However, due to its strong hydrophilicity, if the water is added directly and the stirring is not sufficient, the outer layer absorbs water and expands into a micelle, which will prevent the water from entering the inner layer, thus affecting the play of the role. Therefore, attention must be paid to the correct use. Xanthan gum dry powder can be mixed with salt, sugar and other dry powder accessories and slowly added to the stirring water to make a solution for use.

Thickening

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

Pseudoplasticity

Xanthan gum aqueous solution has a high viscosity under static or low shear action. Under high shear action, the viscosity decreases sharply, 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 malleable. Xanthan gum pseudoplasticity is very prominent, and this pseudoplasticity is extremely effective in stabilizing suspensions and emulsions.

Stability to heat

The viscosity of xanthan gum solution does not change greatly with temperature. General polysaccharides will change their viscosity due to heating, but the viscosity of xanthan gum aqueous solution hardly changes between 10-80 ° C. Even low-concentration aqueous solutions still show stable high viscosity over a wide temperature range. 1% xanthan gum solution (containing 1% potassium chloride) is heated from 25 ° C to 120 ° C. Its viscosity is only reduced by 3%.

Stability to acid and base

Xanthan gum solution is very stable to acid and base, its viscosity is not affected between pH 5-10, and there is a slight change in viscosity when pH is less than 4 and greater than 11. In the range of PH3-11, the difference between the maximum and minimum viscosity is less than 10%. Xanthan gum is soluble in a variety of acid solutions, such as 5% sulfuric acid, 5% nitric acid, 5% acetic acid, 10% hydrochloric acid and 25% phosphoric acid, and these xanthan gum solutions are quite stable at room temperature, and the properties will not change for several months. Xanthan gum is also 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.

Stability to salt

Xanthan gum solution can be mixed with many salt solutions (potassium, sodium, calcium, magnesium, etc.) without affecting its viscosity. Under higher salt concentration conditions, even in saturated salt solutions, it retains its solubility without precipitation and flocculation, and its viscosity is hardly affected.

Stability to enzymatic hydrolysis

The stable double helix structure of xanthan gum makes it highly resistant to oxidation and enzymolysis, and many enzymes such as protease, amylase, cellulase and hemicellulase cannot degrade xanthan gum.

In food, xanthan gum is added to many foods as a stabilizer, emulsifier, suspending agent, thickening agent and processing aid. Xanthan gum can control the rheology, structure, flavor and appearance of products, and its pseudoplasticity can ensure a good taste. Therefore, it is widely used in salad dressings, breads, dairy products, frozen foods, beverages, condiments, brewing, candies, pastries, soups and canned foods.

Tips and Tricks

• Xanthan gum is shear-thin: liquids are sticky when stationary, but become more fluid when agitated or sprayed.
• Higher resting viscosity provides excellent viscosity, such as in solid shaping.
• Stabilizing lotion.
• Adding xanthan gum prevents moisture from leaching out of the puree
• Used to keep particles suspended (e.g. herbs, spices, etc.)
• Xanthan gum reduces starch aging in bread and baked products.
• In ice cream, xanthogenic acid (~ 0.2%) prevents the formation of ice crystals during thawing.
• Xanthan gum helps stabilize cream and mousse.
• Xanthan gum added to gluten-free products prevents the product from breaking and sticking to the product. For best results, use with guar gum in a 2:1 ratio (x: g).

Piña colada espuma

Ingredients: 600g pineapple juice, 350g coconut milk, 50g brown rum, 1g xanthan gum (0.1%) or 10g gelatin (1.0%)

Heat a little pineapple juice and dissolve the gelatin. Add the remaining liquid. If using xanthan gum, it can be added directly to the liquid using a blender or immersion blender. Strain the liquid, transfer to a cream gun and fill with nitrous oxide. Store in the refrigerator for a few hours before use to cool and stabilize.