Carboxymethyl cellulose aka CMC is actually the sodium salt of carboxymethyl cellulose. It is derived from cellulose, which is made water-soluble by a chemical reaction. The water-solubility is achieved by introducing carboxymethyl groups along the cellulose chain, which makes hydration of the molecule possible.
CMC is used as a viscosity modifier or thickener, and to stabilize emulsions in various products including ice cream. CMC is known for its excellent water retaining capacity.
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