FATS AND OILS

 FATS AND OILS

The triester of fatty acids with glycerols (1,2,3-trihydroxypropane) compose the class of lipids known as fats and oils. These triglycerides(or triacylglycerols) are found in both plants and animals, and compose one of the major food groups of our diet. Triglycerides that are solid or semisolid at room temperature are classified as fats, and occur predominantly in animals. Those triglycerides that are liquid are called oils and originate chiefly in plants. although triglycerides from fish are also largely oils.

• As might be expected from the properties of the fatty acids. fats have a predominance of saturated fatty acids, and oils are composed largely of unsaturated acids.
• Thus ,the melting point of triglycerides reflect their composition, as shown by the following examples. Natural mixed triglycerides have some lower melting point, the melting point of lard being near 30°, whereas Olive Oil melts near -6°C.
• Since fats are valued over oils by some Northern European and North american populations, vegetable oils are extensively converted to solid triglycerides (e.g. Crisco) by partial hydrogenation of their unsaturated components. Some of the remaining double bonds are isomerized(to trans) in this operation.