Xanthan Gum
Xanthan Gum is a water-soluble, hydrophilic polysaccharide hydrocolloid, which is made when the simple sugars of corn starch are fermented by the plant bacteria Xanthomonas campestris. The product is further extracted and dried. It is used widely as a thickener and stabilizer due to its unique pseudo-plasticity rheological properties. It can contribute to optimize suspensions by increasing viscosity to help prevent separation and sedimentation. It also can provide moisture retention and optimize food textures.
Xanthan Gum is listed as GRAS and is approved for use in foods; 21CFR Part 172.695.
Xanthan Gum is considered the most versatile hydrocolloid. It is typically an off-white to pale yellow powder with little odor or taste. It is very stable, so it helps products maintain their texture during storge, heating, freezing and thawing. It shows strong shear-thinning behavior or yield stress, meaning that it gets thinner when mixed or shaken, but thickens again when at rest.
Yield Stress is defined as the minimum applied stress required to break the xanthan gum network enough for the product it is being used in to start to flow.
Mayonnaise sets up and holds its structure but spreads easily once sheer is applied.
Salad Dressing stabilizes at rest but flows when it is shaken and/or poured.
Xanthan Gum is a popular gum to use because just a small amount can dramatically improve texture, stability and shelf life. In foods, it is especially useful when manufacturers require a clean texture without relying on traditional starches. In industrial products, its main advantage is its predictable viscosity and added stability across many challenging processing conditions.