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E 410 LOCUST BEAN GUM

in

Commission Directive 98/86/EC

Synonyms Carob bean gum

Algaroba gum

Definition Locust bean gum is the ground endosperm of the seeds of the natural strains of carob tree, Cerationia siliqua (L.) Taub. (family Leguminosae). Consists mainly of a high molecular weight hydrocolloidal polysac charide, composed of galactopyranose and mannopyranose units combined through glycosidic linkages, which may be described chemically as galactomannan

Molecular weight 50 000-3 000 000

Einecs 232-541-5

Assay Galactomannan content not less than 75 %

Description White to yellowish-white, nearly odourless powder

Identification

A. Positive tests for galactose mannose

B. Microscopic examination Place some ground sample in an aqueous solution containing 0,5 % iodine and 1 % potassium iodide on a glass slide and examine under microscope. Locust bean gum contains long stretched tubiform cells, separated or slightly interspaced. Their brown contents are much less regularly formed in guar gum. Guar gum shows close groups of round to pear shaped cells. Their contents are yellow to brown

C. Solubility Soluble in hot water, insoluble in ethanol

Purity

Loss on drying Not more than 15 % (105 °C, 5 hours)

Ash Not more than 1,2 % determined at 800 °C

Protein (N X 6,25) Not more than 7 %

Acid-insoluble matter Not more than 4 %

Starch Not detectable by the following method: to a 1 in 10 solution of the sample add a few drops of iodine solution. No blue colour is produced

Arsenic Not more than 3 mg/kg

Lead Not more than 5 mg/kg

Mercury Not more than 1 mg/kg

Cadmium Not more than 1 mg/kg

Heavy metals (as Pb) Not more than 20 mg/kg

Ethanol and propane-2-ol Not more than 1 %, single or in combination