Galactomannan

Galactomannans are polysaccharides consisting of a mannose backbone with galactose side groups, more specifically, a (1-4)-linked beta-D-mannopyranose backbone with branchpoints from their 6-positions linked to alpha-D-galactose, (i.e. 1-6-linked alpha-D-galactopyranose).

In order of increasing number of mannose-to-galactose ratio:^[1]

• fenugreek gum, mannose:galactose ~1:1
• guar gum, mannose:galactose ~2:1
• tara gum
  , mannose:galactose ~3:1
• locust bean gum or carob gum, mannose:galactose ~4:1
• cassia gum, mannose:galactose ~5:1

Galactomannans are often used in food products to increase the viscosity of the water phase.

Guar gum has been used to add viscosity to artificial tears, but is not as stable as carboxymethylcellulose.^[2]

Food use

Galactomannans are used in foods as stabilisers. Guar and locust bean gum (LBG) are commonly used in ice cream to improve texture and reduce ice cream meltdown. LBG is also used extensively in cream cheese,^{[3][unreliable medical source?]} fruit preparations and salad dressings. Tara gum is seeing growing acceptability as a food ingredient but is still used to a much lesser extent than guar or LBG. Guar has the highest usage in foods, largely due to its low and stable price.

Clinical use

Galactomannan is a component of the cell wall of the mold