Carob bean gum is a food additive, which may result in allergy symptoms in sensitised individuals.

Carob Allergy Test: Allergen Exposure

The carob tree is an evergreen originating in the Middle East, and related to the mesquite, acacia and tragacanth trees. It thrives in hot semi-arid regions and has been cultivated by humans since antiquity, principally for use as a forage crop.

The products of the tree, especially the powder from the pods, are in widespread use both near the tree’s habitats and throughout the industrialised world.

The long, leathery pods from the carob tree contain a sweet, edible pulp (which can be eaten fresh). After drying, the pulp is roasted and ground into a powder, used in making preserves, juices, and liqueurs, as an ingredient in cosmetics, and as a flavouring for cigarettes. It is also used to flavour baked goods and candies.

Carob bean gum is used as a stabiliser and thickening agent, and also used as an egg substitute.

Flour from the pods is used in making bread, pancakes, breakfast cereal and syrup. The sugars can produce fungal protein and alcoholic beverages. Carob is an additive in breakfast foods such as jams, marmalades, and yoghurt. It is used in cake icing, canned poultry and meats, infant food, prepared mustard, and some toothpaste.

The seed gum is employed in the manufacture of cosmetics, pharmaceutical products, detergents, paint, ink, shoe polish, adhesives, sizing for textiles, photographic paper, insecticides and match heads.

Carob Allergy Test: Allergen Description

No allergens from carob have yet been fully characterised, although several have been identified. Heat-processing has been found to deactivate carob protein allergenicity. This has dietary implications for poly-allergic children.

Carob Allergy Test: Potential Cross-Reactivity

Extensive cross-reactivity among the different individual species of the genus could be expected but in fact is not seen frequently. Clinical studies have found that there is little cross-reactivity between members of the legume family. Specifically, there is no cross-allergenicity between carob and peanut.

The molecular structures of carob bean and guar gum are very similar, consisting of a high molecular weight polysaccharide. Allergic reactions to guar gum have been reported. Some degree of cross-reactivity between these plants may be possible.

Carob Allergy Test: Clinical Experience

Carob/Carob gum may uncommonly induce symptoms of food allergy in sensitised individuals.

Allergy to carob gum has been reported in an infant. A 5-month-old child with gastroesophageal reflux was found to be allergic to an anti-regurgitation milk formula containing carob gum as a thickening agent.

Occupational allergy to carob has also been reported. Asthma and rhinitis to carob bean flour has been described in a man who handled carob bean flour as part of his work in a jam factory. After 2 years in his job, he complained of work-related rhinitis and irritated eyes. Asthma appeared 3 years later. Symptoms disappeared over weekends.

Similarly, rhinitis and asthma were described in a man who routinely handled carob bean flour as part of his work as an ice cream maker.

Other reactions

Pollen from the Carob tree has been identified as an important inhalant allergen in Turkey.

When used as a thickening agent in foods, carob bean gum can cause loose, gelatinous stools of sufficient frequency to warrant temporary withdrawal.

The ingestion of Carob bean gum has been shown to cause a significant reduction in the absorption of calcium, iron, and zinc.

Also, the pods contain significant levels of tannins, which may interfere with the body’s utilisation of protein.

Carob pods and leaves, particularly the young leaves, contain a valium-like substance that binds with central and peripheral benzodiazepine receptors.