Carboxymethylcellulose

Carboxymethylcellulose (also known as CMC or cellulose gum) is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodium salt, sodium carboxymethylcellulose.

Chemistry

Carboxymethylcellulose is synthesized by the reaction of cellulose with chloroacetic acid. The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive. The degree of substitution (DS) of carboxymethylcellulose is defined as the average number of carboxymethyl groups per anhydroglucose unit and can be anywhere from 0.4 to 1.5.

Uses

Carboxymethylcellulose is used in food science as a viscosity modifier or thickener, and to stabilize emulsions in various products including ice cream. It is also a constituent of many non-food products, such as toothpaste, laxatives, diet pills, water-based paints, detergents, textile sizing, and various paper products. It is used primarily because it has high viscosity, is nontoxic, and is generally considered to be hypoallergenic.

Health and Safety

Carboxymethylcellulose is generally considered safe for human consumption. It is not absorbed by the body, but rather is passed through the digestive system unchanged. However, like many other additives, it may cause intestinal bloating and discomfort in some individuals.

See Also

• Cellulose
• Food additive
• Emulsion