Triglyceride, also known as triacyclgylcerol, is an ester of glycerol (propane-1,2,3-triol) in which all three hydroxyl groups are esterified with a fatty acid. Trigylcerides are the major constituent of fats and oils and provided a concentrated food energy store in living organisms as well as cooking fats and oils, margarines, etc. Their physical and chemical properties depend on the nature of their constituent fatty acids. In simple triglycerides all three fatty acids are identical; in mixed trigylcerides two or three different fatty avids are present.