Olein

Olein is the common name for 9-octadecenoic acid 1,2,3-propanetriyl ester, the triglyceride composed of glycerol esterified with three molecules of oleic acid, more familiarly known as triolein. The term also denotes the liquid fractions separated during the dry fractionation of oils and fats, such as palm olein, the free-flowing liquid that remains after palm stearin crystallises out. These olein fractions are prized in food manufacturing for their fluidity, mild flavour, and good frying performance. Chemically, olein’s unsaturated structure keeps its melting point low, which explains why olein-rich fractions stay clear and pourable at room temperature while their parent fats would cloud or set.