Locust bean gum

Locust bean gum (LBG, also known as carob gum, carob bean gum, carobin, E410) is a galactomannan vegetable gum extracted from the seeds of the carob tree and used as a thickening agent (gelling agent) in food technology.

Locust bean gum
Other names
Carob gum; Carob bean gum; Carobin
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EC Number
  • 232-541-5
E number E410 (thickeners, ...)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references


It is extracted from the seeds of the carob tree, which is native to the Mediterranean region and nearly 75% were produced by Portugal, Italy, Spain and Morocco in 2016.[1] The seeds contained within the long pods that grow on the tree are used to make this gum. First, the pods are kibbled to separate the seed from the pulp. Then, the seeds have their skins removed by an acid treatment; the deskinned seed is then split and gently milled. This causes the brittle germ to break up while not affecting the more robust endosperm. The two are separated by sieving. The separated endosperm can then be milled by a roller operation to produce the final locust bean gum powder.[2]


Locust bean gum occurs as a white to yellow-white powder. It consists chiefly of high-molecular-weight hydrocolloidal polysaccharides, composed of galactose and mannose units combined through glycosidic linkages, which may be described chemically as galactomannan. It is dispersible in either hot or cold water, forming a sol having a pH between 5.4 and 7.0, which may be converted to a gel by the addition of small amounts of sodium borate. Locust bean gum is composed of a straight backbone chain of D-mannopyranose units with a side-branching unit of D-galactopyranose having an average of one D-galactopyranose unit branch on every fourth D-mannopyranose unit.[3]

Food scienceEdit

The bean, when made into powder, is sweet—with a flavor similar to chocolate—and is used to sweeten foods and as a chocolate substitute, although this carob powder is produced from the fruit pod after removal of seeds, while the gum is produced from the seeds themselves.[4] It is also used in pet foods and inedible products such as mining products, paper making, and to thicken textiles. It is used in cosmetics and to enhance the flavor of cigarettes. Shoe polish and insecticides also have locust bean gum powder as an additive.[5] It is soluble in hot water.[6]

See alsoEdit


  1. ^ "Carob production in 2016; Crops/World Regions/Production Quantity from pick lists". UN Food and Agriculture Organization, Statistics Division. 2017. Retrieved 26 June 2018.
  2. ^ CyberColloids: Locust bean gum production, CyberColloids, Hydrocolloids research and development webpage.
  3. ^ MARTIN GLICKSMAN (1963)UTILIZATION OF NATURAL POLYSACCHARIDE GUMS IN THE FOOD INDUSTRY, Research Center. General Foods Corporation. Tarrytotun. New York
  4. ^ Dakia PA, Wathelet B, Paquot M (2007). "Isolation and chemical evaluation of carob (Ceratonia siliqua L.) seed germ". Food Chemistry. 102 (4): 1368–1374. doi:10.1016/j.foodchem.2006.05.059.
  5. ^ "Locust Bean Gum Powder". Archived from the original on 2012-03-30. Retrieved 2010-12-15.
  6. ^ Martin Chaplin: Locust bean gum Archived 2005-11-05 at the Wayback Machine, London South Bank University, web page.