Basic Information

Glycerol Monostearate Structure
IUPAC Name | : 2,3-dihydroxypropyl octadecanoate |
CAS Number | : 31566-31-1 |
HS Code | : 2915.70 |
Molecular Formula | : C21H42O4 |
Structural Formula | : C17H35COO-CH2-CH(OH)-CH2OH |
Synonyms | : GMS, Glycerol monostearate, Monostearin, Glyceryl stearate, E471 |
Molecular Weight | : 358.56 g/mol |
Description
Glycerol monostearate (GMS) is the monoester of glycerol and stearic acid. It is one of the most widely used food emulsifiers globally, approved as E471, and valued for its ability to stabilize oil-in-water and water-in-oil emulsions, improve texture, and extend the shelf life of food products.
GMS is available in standard grades (40–55% monoglyceride content) and distilled grades (>90% monoglyceride content, also referred to as Distilled Monoglyceride or DMG). The distilled grade offers superior emulsification performance and is preferred in demanding food applications. It is derived from palm oil or animal fat-based sources, with palm-based GMS being preferred for Halal and vegan-certified applications.
Beyond food, GMS is also used in personal care formulations as an emulsifier and co-emulsifier in creams and lotions, in pharmaceutical tablet coatings as a lubricant, and in PVC processing as a lubricant and anti-static agent.
Chemical and Physical Properties
Physical Description | : White to off-white waxy solid, beads, flakes, or powder. |
Color / Form | : White to off-white. |
Odor | : Faint, characteristic fatty odor. |
Taste | : Bland, slightly fatty. |
Boiling Point | : >200 °C (decomposes) |
Melting Point | : 54–72 °C (depending on grade and fatty acid composition) |
Flash Point | : >200 °C |
Solubility | : Insoluble in water; dispersible in hot water; soluble in hot oils and organic solvents. |
Density | : Approx. 0.97 g/cm³ |
HLB Value | : Approx. 3.5–4.5 (lipophilic emulsifier) |
Stability / Shelf Life | : Stable under normal dry storage. Susceptible to hydrolysis under strong acid or alkali conditions. |
Viscosity | : Solid at room temperature; low viscosity liquid when melted above 60 °C. |
Polymerization | : No hazardous polymerization. |

