Locust bean gum is a vegetable gum and natural thickening agent that is extracted from the seeds of the carob tree. The heat- and drought resistant carob tree is indigenous to the Mediterranean region, with Spain, Italy and Portugal being the main producing countries. The carob tree is a member of the legume family and has large, oblong, dark brown curved pods with thickened margins and a leathery shell. The composition of the beans contained therein is roughly 30% coat, 45% endosperm and 25% embryo or germ.
The approved thickening agent is extracted from the endosperm by means of a special grinding- and refinement process. It is a partially digestible polysaccharide consisting of galactose and mannose, similar to guar gum. Locust bean gum is less soluble at room temperature than guar gum. For this reason, it is normally dissolved in hot water. This heat stability is the reason that it is often used in instant soups. In practice, the synergetic effects that can be achieved with other gums, such as xanthan gum, carragenan or agar are often exploited.