Carboxymethylcellulose
What it does
Thickener/stabiliser.
How it's made
From plant cellulose.
Carboxymethylcellulose (CMC), also called cellulose gum, is a modified cellulose used as a thickener, stabiliser and water-binder in ice cream, baked goods, drinks, sauces and gluten-free products. It is one of the most versatile thickening gums, keeping textures smooth and stopping ice crystals and separation.
It is made from purified cellulose (from wood pulp or cotton) by reacting it with an alkali and then with chloroacetic acid. This attaches carboxymethyl groups to the cellulose chains, which transforms the insoluble natural fibre into a gum that dissolves in water and thickens it.
The modified cellulose is washed to remove reaction by-products (mainly salt), then dried and milled into a white to cream powder standardised for viscosity. In ice cream it controls texture and slows melting, and in gluten-free baking it helps mimic the structure gluten would provide; it is plant-derived and suitable for vegetarians and vegans.
Possible reactions
Emulsifiers like this are studied for gut-microbiome effects; debated.