Glycerin also called glycerine or glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in those lipids known as glycerides. Due to having antimicrobial and antiviral properties it is widely used in wound and burn treatments. It can also be used as an effective marker to measure liver disease. It is also widely used as a sweetener in the food industry and as a humectant in pharmaceutical and food formulations. Owing to the presence of three hydroxyl groups, glycerol is miscible with water and is hygroscopic in nature.

Usages and Applications:

Food industry

In food and beverages, glycerol serves as a humectant (maintaining moisture), solvent, and sweetener, and may help preserve foods. It’s used extensively in industrial breakfast cakes to keep it moist and prevent staling. It is also used as filler in commercially prepared low-fat foods (e.g., cookies). As a sugar substitute, it has approximately 27 kilocalories per teaspoon (sugar has 20) and is 60% as sweet as sucrose. It does not feed the bacteria that form plaques and cause dental cavities so it’s used in dietary products extensively. It is also recommended as an additive when using polyol sweeteners such as sorbitol and xylitol (most prevalently used in chewing gums) which have a cooling effect, due to its heating effect in the mouth, if the cooling effect is not wanted. As a food additive, glycerol is labeled as E number E422. It is added to icing (frosting) to prevent it from setting too hard.

Pharmaceutical and Personal Hygiene

Glycerin is used in medical, pharmaceutical and personal care preparations, often as a means of improving smoothness, providing lubrication, and as a humectant.

Ichthyosis and psoriasis have been relieved by the topical use of glycerin. It is found in allergen immunotherapies, cough syrups, elixirs and expectorants, toothpaste, mouthwashes, skin care lotions, creams and balms, shaving cream, hair care products, soaps. In solid dosage forms like tablets, glycerin is used as a tablet holding agent. Glycerin is a component of glycerin soaps where essential oils are added for fragrance. This kind of soap is used by people with sensitive, easily irritated skin because it prevents skin dryness with its moisturizing properties. It draws moisture up through skin layers and slows or prevents excessive drying and evaporation.

Glycerin has also been traditionally used in cigarette manufacturing to keep the moisture in the tobacco but has, of late, found new usage in e-cigarettes and vaping products as well.

Economically it may be noted; since synthetic glycerin is a major by-product of biodiesel fuel manufacturing, at times of high petroleum prices when biodiesel fuel is more in demand, glycerin prices tend to be depressed.