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:
*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 ~4:1Galactomannans are often used in food products to increase the viscosity of the water phase.

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, fruit preparations and salad dressings. Tara 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. [http://www.cybercolloids.net/library/carob/lbgprops.php Article on LBG]

Clinical use

Galactomannan is a component of the cell wall of the mold "Aspergillus" and is released during growth. Detection of galactomannan in blood is used to diagnose invasive aspergillosis infections in humans. This is performed with monoclonal antibodies in a double-sandwich ELISA assay from Bio-Rad Laboratories was approved by the FDA in 2003 and is of moderate accuracy. [cite journal | author= Pfeiffer CD, Fine JP, Safdar N | title=Diagnosis of invasive aspergillosis using a galactomannan assay: a meta-analysis | journal=Clin Infect Dis | year=2006 | volume=42 | pages=1417–27 | doi=10.1086/503427 ] The assay is most useful in patients who have had hemopoetic cell transplants (stem cell transplants).

The tears of the eye can be supplemented with artificial lubricants to improve eye comfort. An independent clinical trial [cite journal | author= Hartstein I, Khwarg S, Przydryga J | title=An open-label evaluation of HP-Guar gellable lubricant eye drops for the improvement of dry eye signs and symptoms in a moderate dry eye adult population| journal=Curr Med Res Opin | year=2005 | volume=21 | pages=255–260 | doi=10.1185/030079905X26252 ] has shown that lubricant eye drops containing HP Guar provide significant improvement of comfort in people with "dry-eye".

References


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Look at other dictionaries:

  • Galactomannan — Galactomannane (oder Galaktomannane) sind Stärke ähnliche Substanzen aus verzweigten Ketten von Kohlenhydraten, überwiegend Galactose und Mannose. Vorkommen und Bedeutung Hauptbestandteil der Guarbohne, aus der das Verdickungsmittel Guarkernmehl… …   Deutsch Wikipedia

  • galactomannan — noun Any of a class of polysaccharides, found in many gums, having a backbone composed of mannose with galactose sidechains …   Wiktionary

  • galactomannan — ga·lac·to·mannan …   English syllables

  • galactomannan — A gum in which the structural chain is made up of D mannose units with 1?4 linkages. The ratio of galactose to mannose is 1:2 …   Glossary of Biotechnology

  • galactomannan — “+ noun Etymology: galact + mannan : any of several polysaccharides that occur especially in seeds (as locust beans) and yield galactose and mannose on hydrolysis …   Useful english dictionary

  • Galactomannane — (oder Galaktomannane) sind Stärke ähnliche Substanzen aus verzweigten Kohlenhydrat Ketten. Die Hauptkette besteht dabei aus Mannose, wobei in verschiedenen Abständen kurze Seitenketten aus jeweils einem Galactose Molekül auftreten.[1] Struktur… …   Deutsch Wikipedia

  • Galaktomannan — Galactomannane (oder Galaktomannane) sind Stärke ähnliche Substanzen aus verzweigten Ketten von Kohlenhydraten, überwiegend Galactose und Mannose. Vorkommen und Bedeutung Hauptbestandteil der Guarbohne, aus der das Verdickungsmittel Guarkernmehl… …   Deutsch Wikipedia

  • Galaktomannane — Galactomannane (oder Galaktomannane) sind Stärke ähnliche Substanzen aus verzweigten Ketten von Kohlenhydraten, überwiegend Galactose und Mannose. Vorkommen und Bedeutung Hauptbestandteil der Guarbohne, aus der das Verdickungsmittel Guarkernmehl… …   Deutsch Wikipedia

  • Guar — Not to be confused with Gaur or Gwar. Guar Guar bean cluster Scientific cl …   Wikipedia

  • Locust bean gum — (also known as carob gum, carob bean gum, carobin, E410) is a galactomannan vegetable gum extracted from the seeds of the Carob tree. It is used as a thickening agent and gelling agent in food technology. It is soluble in hot water. [Martin… …   Wikipedia


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