ion exchange exclusion, both cationic and ionic ion exchanges, vacuum flash evaporation, thin film distillation, and heating to produce a 100% pure glycerol.

Humectants are used in stabilization of food products and lengthening shelf life through food and moisture control. The available moisture determines microbial activity, physical properties, sensory properties and the rate of chemical changes, that if not controlled, are the cause of reduced shelf life. Examples are dry cereal