Glycerol
The short version
A natural sugar alcohol — the dominant humectant and freeze-point depressor in many soft-textured foods.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
A by-product of soap manufacture and biodiesel production (transesterification of triglycerides); the dominant industrial source today is biodiesel. Also produced by direct fermentation of glucose. A natural component of all triglyceride fats — the glycerol backbone of every lipid in our diet.
How it's used
The leading food humectant — keeps moisture in icings, frostings, soft candies, fondants, fudges, marshmallows, protein bars, and chewing gum. Provides body and texture, lowers water activity (extending shelf life), and depresses freezing point in ice cream. Mildly sweet (~60% sucrose) but used mainly for texture.
Safety profile
ADI not specified — considered safe. Endogenous lipid component, metabolized to glucose via the glycerol-3-phosphate pathway. Caloric value is similar to carbohydrates (4 kcal/g). Unlike sorbitol or xylitol, glycerol is well-absorbed and does not cause laxative effects at typical doses.
Physical & chemical properties
Clear, colorless, viscous, hygroscopic liquid. Completely miscible with water and lower alcohols. Sweet warming taste. Stable in storage; non-volatile.
Regulation worldwide
Permitted globally without restrictive limits — quantum satis in most food categories. The dominant food humectant by volume.
Educational information only. Not medical or dietary advice.