XANTHAN GUM

Ruth Winter.1978. A Consumer's Dictionary of Food Additives. Crown Publishers, Inc., New York.

A polysaccharide gum produced on a commercial basis from the fermentation of corn sugar by the bacterium Xanthomonas campestris. The United States Agriculture Department has asked for the3 use of xanthan gum as a necessary ingredient in packaging meat and poultry products. It is now used to thicken, suspend, emulsify, and stabilize water-based foods, such as dairy products and salad dressings. It is also used as "pseudoplasticizer" in salad dressings to help them pour well. No known toxicity.

a microbial produced from the fermentation of corn sugar, xanthan gum is used as a thickener, emulsifier and stabilizer in foods such as dairy products and salad dressings.

Igoe, Robert S. 1983. Dictionary of Food Ingredients. Van Nostrand and Reinhold Company.

is a gum obtained by microbial fermentation from the Xanthomonas campestris organism. It is very stable to viscosity change over varying temperatures, pH, and salt concentrations. It is also very pseudoplastic which results in a decrease in viscosity with increasing shear. It reacts synergistic ally with guar gum to provide an increase in viscosity or gel formation. It is used in salad dressings, sauces, desserts, baked goods, and beverages at 0.05 to 0.50%.

Excerpts from Bender, Arnold E. 1990. Dictionary of Nutrition and Food Technology. Butterworths, Boston.

Complex polymer made by bacterial fermentation; stable to wide of pH and temperatures; used as thickening agent to form gels, increase viscosity in foods.

Xanthan is an anionic bacterial polysaccharide composed of a ó -(1->4)-D-Glc (1->4)-beta-D-Glc (cellulosic) backbone with a trisaccharide sidechain linked to C3 of every second glucose residue. The sidechain is ó -D-Man-(1->4)- ó -D-GlcA-(1\->2)-6-O-acetyl-alpha-D-Man-(1\-> beta-D-Man-(1->4)-beta-D-GlcA-(1->2)-alpha-D-Man-(1-> with approximately 60% of the terminal mannose units being pyruvylated and 90% of the proximal mannose units substituted at C6 with O-acetyl groups. It has side chains of side chains 2 mannose and 1 gluconic glucuronic acid group [Cp Kelco].

Xanthomonas campestris is exocellular coating of bacteria developed and grown through the fermentation process. Xanthan gum is an exocellular polysaccharide produced by fermentation of the bacteria Xanthomonas campestris.

Key Characteristics	Description
Solubility in Cold Water	dispersed hydrated to form pseudoplastic mixtures [CP Kelco]; high water solubility (ref Fennema, 1996)
Salt Solutions	compatile compatible and stable in solutions with high salt concentrations[Cp Kelco]
Others	Unique enzyme resistance.May increase or maintain viscosity as heated Affected by shear but recoversand is resistant stabilizes solid, liquid and gaseous dispersions acid sensitive to dissociation; increases viscosity dispersions highly pseudoplastic
pH

Uses Cp Kelco indicates the gum provides visibly clear solutions even at high concentrations. Xanthan gum is commercially available in both clarified and non-clarified forms. Clarified xanthan gives visibly clear solutions even at high xanthan concentrations, while unclarified xanthan solutions are opaque.

Fennema (1996) lists it as emulsion stabilizer; holds water; enhances freeze-thaw stability; inibits starch retrogradation; improves shelf life and serves to bring about stabilization of dispersions, suspensions, and emulsions, thickener.

Features and Benefits:

provides visibly clear solutions even at high concentrations
soluble in both hot and cold water
impart high solution viscoisty at low polysaccharide concentrations
viscosity change minimal over wide temperature range
soluble and stable in both acidic and alkaline solutions
compatile and stable in solutions with high salt concentrations
highly resistant to enzymatic degradation
good lubricity
impart freeze/thaw stability
extremely effective emulsion stabilizer
excellent mouthfeel
synergistic with guar and locust bean gum <

Structure provided by Cp Kelco

Xanthan is an anionic bacterial polysaccharide composed of a ó -(1->4)-D-Glc (1->4)-beta-D-Glc (cellulosic) backbone with a trisaccharide sidechain linked to C3 of every second glucose residue. The sidechain is ó -D-Man-(1->4)- ó -D-GlcA-(1\->2)-6-O-acetyl-alpha-D-Man-(1\-> beta-D-Man-(1->4)-beta-D-GlcA-(1->2)-alpha-D-Man-(1-> with approximately 60% of the terminal mannose units being pyruvylated and 90% of the proximal mannose units substituted at C6 with O-acetyl groups. Side chains 2 mannose and 1 gluconic glucuronic acid group

IMAGES

FREQUENTLY ASKED QUESTIONS

REFERENCES/RESOURCES

Compiled for Food Resource http://food.oregonstate.edu