Commission Directive 2008/84/EC (repealed)Show full title

E 469 ENZYMATICALLY HYDROLYSED CARBOXYMETHYLCELLULOSE

Synonyms	Sodium carboxymethyl cellulose, enzymatically hydrolysed
Definition	Enzymatically hydrolysed carboxymethylcellulose is obtained from carboxymethylcellulose by enzymatic digestion with a cellulase produced by Trichoderma longibrachiatum (formerly T. reesei)
Chemical name	Carboxymethyl cellulose, sodium, partially enzymatically hydrolysed
Chemical formula	Sodium salts of polymers containing substituted anhydroglucose units with the general formula:
	[C6H7O2(OH)x(OCH2COONa)y]n
	where n is the degree of polymerisation
	x = 1,5 to 2,8
	y = 0,2 to 1,5
	x + y = 3,0
	(y = degree of substitution)
Formula weight	178,14 where y = 0,2
	282,18 where y = 1,5
	Macromolecules: Not less than 800 (n about 4)
Assay	Not less than 99,5 %, including mono- and disaccharides, on the dried basis
Description	White or slightly yellowish or greyish, odourless, slightly hygroscopic granular or fibrous powder
Identification
A. Solubility	Soluble in water, insoluble in ethanol
B. Foam test	Vigorously shake a 0,1 % solution of the sample. No layer of foam appears. This test distinguishes sodium carboxymethyl cellulose, whether hydrolysed or not, from other cellulose ethers and from alginates and natural gums
C. Precipitate formation	To 5 ml of a 0,5 % solution of the sample add 5 ml of a 5 % solution of copper or aluminium sulphate. A precipitate appears. This test distinguishes sodium carboxymethyl cellulose, whether hydrolysed or not, from other cellulose ethers and from gelatine, carob bean gum and tragacanth gum
D. Colour reaction	Add 0,5 g of the powdered sample to 50 ml of water, while stirring to produce a uniform dispersion. Continue the stirring until a clear solution is produced. Dilute 1 ml of the solution with 1 ml of water in a small test tube. Add 5 drops of 1-naphthol TS. Incline the tube, and carefully introduce down the side of the tube 2 ml of sulphuric acid so that it forms a lower layer. A red-purple colour develops at the interface
E. Viscosity (60 % solids)	Not less than 2,5 kgm-1s-1 at 25 oC corresponding to an average molecule weight of 5 000 D
Purity
Loss on drying	Not more than 12 % (105 oC to constant weight)
Degree of substitution	Not less than 0,2 and not more than 1,5 carboxymethyl groups per anhydroglucose unit on the dried basis
pH of a 1 % colloidal solution	Not less than 6,0 and not more than 8,5
Sodium chloride and sodium glycolate	Not more than 0,5 % singly or in combination
Residual enzyme activity	Passes test. No change in viscosity of test solution occurs, which indicates hydrolysis of the sodium carboxymethyl cellulose
Lead	Not more than 3 mg/kg