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E 412 - Guar gum

COMMISSION REGULATION (EU) No 231/2012 of 9 March 2012

Synonyms

Gum cyamopsis; Guar flour

Definition

Guar gum is the ground endosperm of the seeds of strains of the guar plant, Cyamopsis tetragonolobus (L.) Taub. (family Leguminosae). Consists mainly of a high molecular weight hydrocolloidal polysaccharide composed of galactopyranose and mannopyranose units combined through glycosidic linkages, which may be described chemically as galactomannan. The gum may be partially hydrolysed by either heat treatment, mild acid or alcaline oxidative treatment for viscosity adjustment.

Einecs: 232-536-0

Chemical name:

Chemical formula:

Molecular weight: 50 000-8 000 000

Assay: Galactomannan content not less than 75 %

Description

A white to yellowish-white, nearly odourless powder

Identification

Test for galactose: Passes test

Test for mannose: Passes test

Solubility: Soluble in cold water

Purity

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

Ash: Not more than 5,5 % determined at 800 °C

Acid-insoluble matter: Not more than 7 %

Protein: Not more than 10 % (factor N x 6,25)

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)

Organic peroxides: Not more than 0,7 meq active oxygen/kg sample

Furfural: Not more than 1 mg/kg

Pentachlorophenol: Not more than 0,01 mg/kg

Arsenic: Not more than 3 mg/kg

Lead: Not more than 2 mg/kg

Mercury: Not more than 1 mg/kg

Cadmium: Not more than 1 mg/kg