EFSA Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food on a request from the Commission related to an application on the use of partially depolymerised guar gum as a food additive

Publication Date:18 September 2007    

The European Food Safety Authority has been asked to provide a scientific opinion on the safety in use of partially depolymerised guar gum as a thickener, emulsifier and stabiliser in food.

Guar gum (E412) is authorised for use as a food additive in the European Union (EU) by European Parliament and Council Directive 95/2/EC. It is currently used as a thickener, emulsifier and stabiliser in a range of food categories.

A 'not limited' ADI was originally set for guar gum by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1973, which was further confirmed by JECFA in 1975.
Specifications for guar gum have been established by the Commission and are laid down in Commission Directive 96/77/EC. The description included within the specification for guar gum in this Directive states that guar gum is the ground endosperm of the seeds of the natural strains of the guar plant, Cyamopsis tetragonolobus (L.) Taub. (family Leguminosae). It 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.

A manufacturer has made a request to use partially depolymerised guar gum as a food additive. Partially depolymerised guar gum is produced from guar gum by one of three manufacturing processes which consist of heat treatment, acid hydrolysis or alkaline oxidation, which all exert a partial depolymerisation of the native guar gum. The result is guar gum which is chemically cut into smaller molecular weight sizes and has different viscosity properties.

Partially depolymerised guar gums have been shown to be very similar to native guar gum with respect to the structure of the galactomannan polysaccharide and the composition of the final products, except for the level of salts present in the samples made by acid hydrolysis and alkaline oxidation because of the neutralisation step involved in the manufacturing process. The resulting salts, either sodium citrate (E311) or sodium phosphate (E339) have well established safety records when used as a food additive in food products (Directive 95/2/EC Annex IV).

In conclusion, the safety of native guar gum has been documented. Since the molecular weight of partially depolymerised guar gum appears to fall within the specifications of native guar gum, which is the guar gum already accepted for food use, the Panel concludes that there is no safety concern for the partially depolymerised guar gum prepared by either heat treatment, acid hydrolysis or alkaline oxidation at estimated levels of intake. Click here to see the whole Opinion document.

The Panel considers that the specifications for guar gum may need to be modified to take
account of the increased level of salts and the possible undesirabe byproducts e.g. furfural and peroxides, that may result from the described processes for the production of partially depolymerised guar gum.

Reference
http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1178638739757.htm

Back