Locust bean (carob) gum is the refined endosperm of the seed of the carob tree, an evergreen of the legume family (Ceretonia siliqua). The tree grows extensively in Spain and is cultivated in many other Mediterranean countries. Locust bean gum like Guar gum is a galactomannan with a backbone of (1-4) β-D-mannopyranosyl units having branches of (1-6)-linked α-D-galactopyranosyl units. However, Locust bean gum has substantially fewer side chains than guar gum and these are clustered in blocks leaving longer regions of unsubstituted mannosyl regions. The gum is only partially soluble in water and suspensions require heating before solubility is achieved. As with guar the polysaccharide forms gels with other gums such as carrageenan and xanthan. Applications are in the food industry to enhance texture, in paper making and in the textile industry.