Features of xanthan gum
Xanthan gum is currently the international set of thickening, suspension, emulsification, stability in one, the most superior performance of biological glue. The amount of pyruvate at the end of the molecular side chain of xanthan gum has great influence on its properties. Xanthan gum has the general properties of long chain polymers, but it contains more functional groups than general polymers, and it shows unique properties under specific conditions. Its conformation in aqueous solution is diverse and exhibits different properties under different conditions.
1. Suspension property and emulsifying property
Xanthan gum is with good suspension effect for insoluble solid and oil drop.
2. Good water solubility
Xanthan gum can be dissolve rapidly in water. It is with very good water solubility. It especially also can be dissolve in cold water, so that it can omits complicated processing procedures and makes the application convenient.
3. Thickening property
Xanthan gum solution is with properties of low concentration and high viscosity (viscosity of its 1% aqueous solution is equal to 100 times of gelatin). It’s a kind of efficient thickening agent.
4. Pseudoplasticity
Xanthan gum aqueous solution is with high viscosity under static state or low shearing action; its viscosity will be sharp dropped under high shearing action while the molecular structure won’t be changed. When the shearing action is eliminated, the original viscosity will be recovered immediately. The relationship between shearing action and viscosity are totally malleable. The pseudoplasticity of xanthan gum is very outstanding. This kind of pseudoplasticity is very effective for stabilizing suspension liquid and emulsion.
5. Stability for temperature
The viscosity of xanthan gum doesn’t be changed with the temperature changes. General polysaccharide appears viscosity variation because of heating while the viscosity of xanthan gum aqueous solution appears scarcely any changes in 10—80¡æ. Even though the low concentration aqueous solution is in wide temperature scope, it still shows stable high viscosity.
6. The stability for acid-base
Xanthan gum solution is very stable for acid-base. Its viscosity won’t be affected in the PH scope 5-10; when the PH is less than 4 or more than 11, its viscosity has slight change.
7. The stability for salt
Xanthan gum solution can mix with many salt solutions (kali salt, sodium salt, calcium salt, magnesium salt and others) and its viscosity won’t be affected. Under the hyper-salt concentration, it still keeps its solubility and is free of precipitation and flocculation in saturated salt solutions, and its viscosity is hardly affected.
8. The stability for enzymatic hydrolysis
The stable double helix structure of xanthan gum is with extremely strong anti-oxidation and anti-oxidation performance. Many enzymes, such as protease, amylase, cellulose and hemicellulase, they can’t degrade the xanthan gum.
Applicantion of xanthan gum in food
As a food additive, xanthan gum has been accepted by many countries. This kind of polysaccharide remarkably improves the texture, taste, appearance through controlling the rheology action of the product, improve its commercial value; in beverage, cake and pastry, jelly, canned food, sea food, meat product processing and other industries, it has become important stabilizer, suspending agent, emulsifier, thickening agent, adhesion agent and processing material with high added-value and quality. It can be concretely summarized into following aspects.
1. Acid-resisting salt-tolerant thickening stabilizer
Be applicable to various kinds of juice beverage, fruit juice concentrate, food with seasoning (such as soybean sauce, oyster sauce, salad sauce). The stabilization effect of xanthan gum is obviously batter than other gum. It is with extremely strong heat stability so that ordinary high temperature sterilization has no effect to it.
2. Emulsifier
As an emulsifier, it is applied in various kinds of protein drink, milk beverage, etc to prevent oil-water stratification and improve protein stability, prevent protein sediment. It is also used as foaming agent and foam stabilizer based on its emulsifying capacity.
3. Filling agent
As stable high viscosity filler, it can be applied in processing of various kinds of dessert, bread, biscuit, candy, etc. Under the condition that the traditional flavor of the food is not changed, it can make the food with more preferable shape preserving property, longer expiration period and batter taste. It is beneficial to the food diversification and industrialization scale production. In the production process of various kinds of frozen foods, xanthan gum it is with function for preventing water loss, delaying aging and prolonging quality guarantee period.
4. Emulsion stabilizer
As an emulsion stabilizer, it is applied in frozen foods. In ice cream, sorbet, xanthan gum can adjust the viscosity of mixture and make its composition uniform and stable and its tissue soft and smooth. Since the relation between the viscosity of xanthan gum and temperature has plasticity and shearing property, during the processing, its viscosity is reduced and the resistance is decreased, so that it is in favor of processing; however, during the aging stage, viscosity is recovered so that it is beneficial to improving expansion rate, preventing the generation of large ice particles in ice cream tissue and making the taste of ice cream more fine and smooth. Meanwhile, it also improves the freeze-thaw stabilization of the product.
5. Application in flour product
In flour product, xanthan gum is a kind of additive worth being promoted. In the producing process of fine dried noodles, noodles and instant noodles, the added xanthan gum can improve gluten power of dough; the dough sheet extruded is with toughness and is reduced broken rate after drying, meanwhile it also improve taste and make it chewy, fresh and smooth; for frying cooking, it also can save oil and reduce cooking cost.
6. Other application
Except for the applications above, xanthan gum is also widely used in processing of meat food, fruit and vegetable fresh-keeping cans and other foods.
