Beverage Plants IV- Carob

Carob powder is derived from the pods of  Ceratonia siliqua, a leguminous tree native to the Mediterranean region. The pod consists of 90% pulp and 10% seed. Among other uses, the pulp, which is high in sugar (48-56%) and protein, can be prepared as a chocolate substitute after drying and roasting. In Turkey, Malta, Portugal, Spain and Sicily, a compote, a liqueur and syrup are made from the pulp.  The species is ordinarily dioecious (pistillate {female} and staminate {male} flowers are on separate trees) but in some varieties trees are bisexual.

Carob as available in many grocery stores

Carob as available in many grocery stores

There now are many varieties of this single species and they are grown commercially for both cattle feed and human food especially in southern Europe. Ripe fruits are rich in tannins which impart some astringency, and the seed coat contains antioxidants. The seed endosperm is a source of carob bean gum, a polysaccharide consisting of mannose and galactose sugar units that is often converted into a colloid or gel and then added  to dairy products, sauces, etc. to thicken the product.  Note than in the food industry, the carob-derived gum is generally known as locust bean gum.

 

Ceratonia siliqua pods, leaves, flowers and seeds

Ceratonia siliqua pods, leaves, flowers and seeds

The natural distribution of the carob is not fully defined within the Mediterranean basin because it has been introduced by humans into many countries over the centuries. In Spain and Portugal. the wild carob survives only on the Atlantic coast. In Greece and Italy the ancient Greeks apparently planted it, and the Arabs introduced it as far west as Morocco and Spain far from its probable native haunts in the eastern Mediterranean. It is also reported as growing wild in southern coastal Turkey, in Syria and perhaps in Cyrenaica (eastern coastal Libya). Elsewhere in the Mediterranean Basin, it is cultivated only in warmest coastal areas such as Sicily, Cyprus, Crete and Majorca, but there is a report that it was widely used in the 19th century in reforestation of the slopes of the Appenine Mountains of peninsular Italy. The success of these efforts is uncertain.

Spanish missionaries brought the carob to California and Mexico and it was introduced later to Texas, Arizona and elsewhere in California. Israel, (where possibly native)  and Dalmatia also served as seed sources for American introductions.  Artificial selection and propagation has produced many varieties that further expanded its distribution in Brazil, Hawaii, Chile and elsewhere. In Florida it grows on dry soils but pod productivity is rather low due at least in part to the wet Florida summers which contrast strongly with the Mediterranean climate. 

Ripe carob pods ready for harvest.

Ripe carob pods ready for harvest.

In one of the few chemical analyses of carob, a total of 24 polyphenol compounds were identified with a yield of 3.94 g/kg (dry weight). The profile was dominated by gallic acid in various forms (72% of the total), plus flavenoids which totaled 26% of the total.). These data indicate that carob fibre is rich in both amount and variety of phenolic antioxidant substances, and its inclusion in the diet may reduce the risk of contracting cardiovascular disease. Carob oil is also rich in fatty acids. Like chocolate, carob contains the alkaloids caffeine and theobromine but in significantly smaller quantities.