Locust bean gum (LBG), also known as Carob gum, is derived from the seeds of the Carob tree. The tree goes under many different names in various parts of the world. Furthermore, in some countries such as Italy there are regional variations in the naming. The most well known names internationally are Carob and Locust bean. Other regional names include Johannisbrotbaum (Germany), Alfarrobeira (Portugal) and Garrofer or Garrover (Catalonia).
Did you know?
The Carob has a very uniform seed size, about 200mg and was used as a standard weight in medieval times by jewellers. It has been perpetuated until this day as the unit of gold measurement the carat.
The Carob tree has been recognised as a valuable resource for many centuries. Its origins lie in the middle east where it grows in dry areas with poor soils. The Ancients Greeks brought the Carob tree from its native lands to the Mediterranean basin whereas Arabs moved the tree along the north African coast and into Spain and Portugal. Hence it is believed that the Carob that occurs wild in the Mediterranean basin is actually a domesticated species that has ‘gone wild’ rather than an intrinsic wild species of that area. The history of the Carob tree in the USA is somewhat clearer and more recent being introduced into the USA by the Patents Office in 1854. The Carob is scientifically called Ceratonia siliqua and is regarded as a very ancient leguminous plant. It is placed in the tribe Cassieae although there is some dispute about exactly where Carob fits taxonomically (Irwin and Barnaby 1981). Interestingly two new subspecies of Ceratonia where first described as late as 1980, one from Oman and the other from Somalia, possibly the distant relatives and original stock of the Ceratonia now grown commercially.
The Carob tree is important in the Mediterranean basin as a crop that can be grown on marginal lands where few other crops can be grown economically. Traditionally Carob trees are inter planted with olives, grapes and nuts. The Carob pods with their high sugar content are then used as cattle fodder. More recently the major interest in the Carob tree has been the extraction of the gum from the seeds.
Additional information on Carob & LBG structure, production and properties can be accessed using the arrows in the Further Reading box below or by downloading the pdf here.