A substance that promotes retention of moisture.

A humectant is a hygroscopic substance that is used as a food additive. Since hygroscopic substances absorb water from the air, the addition of a humectant has the effect of keeping the foodstuff moist. It is often a molecule with several hydrophilic groups, most often hydroxyl groups, but amines and carboxyl groups, sometimes esterified, can be encountered as well; the affinity to form hydrogen bonds with molecules of water is crucial here.

Humectants are sometimes used as a component of antistatic coatings for plastics. Humectants are also found in many cosmetic products where moisturization is desired, including treatments such as moisturizing hair conditioners.

Examples of humectants include glycerine, propylene glycol (E 1520) and glyceryl triacetate (E1518). Others can be polyols like sorbitol (E420) or maltitol (E965), polymeric polyols like polydextrose (E1200) or natural extracts like quillaia (E999), or lactic acid or urea.

Food additives