Locust bean gum
Locust beans in a pod
Carob gum; Carob bean gum; Carobin
|E number||E410 (thickeners, ...)|
CompTox Dashboard (EPA)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 is extracted from the seeds of the carob tree, which is native to the Mediterranean region. In 2016, nearly 75% of global production came from Portugal, Italy, Spain and Morocco. The seeds are contained within long pods that grow on the tree. First, the pods are kibbled to separate the seed from the pulp. Then, the seeds have their skins removed by a acid or heat treatment. Acid treatment yields a lighter coloured gum than heat treatment.:222 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. Alternatively, the gum can be extracted from the seeds with water, precipitated with alcohol, filtered, dried and milled, to give a very pure "clarified" locust bean gum.:223
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.
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. 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. It is soluble in hot water.
- "Carob production in 2016; Crops/World Regions/Production Quantity from pick lists". UN Food and Agriculture Organization, Statistics Division. 2017. Retrieved 26 June 2018.
- Giri, Tapan Kumar; Ghosh, Bijaya (2021-06-12). Plant and Algal Hydrogels for Drug Delivery and Regenerative Medicine. Woodhead Publishing. ISBN 978-0-12-821650-7.
- CyberColloids: Locust bean gum production, CyberColloids, Hydrocolloids research and development webpage.
- Glicksman, Martin (1963), Utilization of Natural Polysaccharide Gums in the Food Industry, Advances in Food Research, vol. 11, Elsevier, pp. 109–200, doi:10.1016/s0065-2628(08)60065-8, ISBN 978-0-12-016411-0, retrieved 2021-09-20
- 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.
- "Locust Bean Gum Powder". Archived from the original on 2012-03-30. Retrieved 2010-12-15.
- Martin Chaplin: Locust bean gum Archived 2005-11-05 at the Wayback Machine, London South Bank University, web page.