carboxymethyltransferase

carboxymethylcellulose is a cellulose derivative where carboxymethyl groups (-CH2COOH) are attached to some of the hydroxyl groups in the cellulose backbone. It is produced by reacting cellulose with sodium chloroacetate under alkaline conditions. This modification makes cellulose water-soluble and imparts various useful properties.

The degree of substitution, which refers to the average number of carboxymethyl groups per anhydroglucose unit in the cellulose chain, can be controlled during synthesis and influences the properties of the final product. Carboxymethylcellulose is a common additive used in a wide range of industries. It functions primarily as a thickener, binder, stabilizer, and film-former.

In the food industry, it is often found in ice cream, baked goods, and beverages to improve texture and prevent ice crystal formation. In pharmaceuticals, it serves as a binder in tablets and a viscosity enhancer in suspensions and eye drops. The paper industry uses it as a sizing agent to improve surface properties. It is also employed in detergents as an anti-redeposition agent, preventing dirt from settling back onto fabrics. Carboxymethylcellulose is generally considered safe and is regulated by food and drug administrations worldwide.