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