Xanthan gum is a light yellow to white flowable powder with a slight odor. Easily soluble in cold and hot water, the solution is neutral, resistant to freezing and thawing, and insoluble in ethanol. When exposed to water, it disperses and emulsifies into a stable hydrophilic viscous colloid.
Xanthan gum has the following 9 properties:
1. Typical rheological characteristics:
As the shear rate increases, the colloidal network is destroyed, causing the viscosity to decrease and the glue to become thinner. However, once the shear force disappears, the viscosity returns to Recoverable, thus giving it good pumping and processing properties. This characteristic is used to add xanthan gum to liquids that require the addition of thickeners. Not only does the liquid flow easily during transportation, but it can also return to the required viscosity after resting. Therefore, it is widely used in the beverage industry.
2. High viscosity at low concentration:
Liquid containing 2% to 3% xanthan gum has a viscosity of up to 3~7Pa·s. Its high viscosity makes it have broad application prospects, but at the same time it brings trouble to post-processing in production. Monovalent salts such as 0.1% NaCl and divalent salts such as Ca and Mg can slightly reduce the viscosity of low-glue solutions below 0.3%, but can increase the viscosity of higher-concentration glue solutions.
3. Heat resistance:
Xanthan gum has a viscosity of almost No changes. Even if it is kept at a high temperature of 130°C for 30 minutes and then cooled, the viscosity of the solution does not change significantly. The viscosity of the glue does not change after multiple freeze-thaw cycles. When salt is present, the solution has good thermal stability. If a small amount of electrolyte such as 0.5% NaCl is added under high temperature conditions, the viscosity of the glue can be stabilized.
4. Acid and alkaline resistance:
The viscosity of xanthan gum aqueous solution has almost nothing to do with pH. This unique property is not possessed by other thickeners such as carboxymethyl cellulose (CMC). If the concentration of inorganic acid in the glue solution is too high, the glue will be unstable; acid hydrolysis of polysaccharides will occur at high temperatures, causing the viscosity of the glue to decrease. If the NaOH content is greater than 12%, xanthan gum may gel or even precipitate. If the sodium carbonate concentration exceeds 5%, it may also cause gelation.
5. Resistant to enzymatic hydrolysis:
Due to the shielding effect of the side chains, the xanthan gum skeleton is unique in that it is not hydrolyzed by enzymes. ability.
6. Compatibility:
Xanthan gum can be miscible with most commonly used food thickener solutions, especially After being mixed with alginates, starch, carrageenan, and carob gum, the viscosity of the solution increases in a superimposed manner. It shows good compatibility in aqueous solutions in the presence of various salts. However, high-valent metal ions and high pH will make them unstable. Adding complexing agents can prevent the occurrence of incompatibility.
7. Solubility:
Xanthan gum is easily soluble in water, but insoluble in polar solvents such as alcohols and ketones. It is readily soluble in water over a very wide range of temperature, pH and salt concentrations, and its aqueous solutions can be prepared at room temperature with agitation that minimizes air incorporation. If xanthan gum is mixed with some dry substances such as salt, sugar, MSG, etc. in advance, then moistened with a small amount of water, and finally mixed with water, the prepared glue will have better performance. It can be dissolved in many organic acid solutions and has stable performance.
8. Dispersibility:
The holding capacity of 1% xanthan gum solution is 5N/m2, which is one of the best food additives. Excellent suspending agent and emulsion stabilizer.
9. Water retention:
Xanthan gum has good water retention and freshness preservation effects on food.