Functions of dietary fats
In 1929, George and Mildred Burr introduced the concept of essential fats: that fat might be necessary for the proper growth and development of animals and possibly humans.
Dietary fat includes all the lipids in plant and animal tissues that are eaten as food. The most common fats (solid) or oils (liquid) are glycerolipids, which are essentially composed of triacylglycerols.
The triacylglycerols are accompanied by minor amounts of phospholipids, monoacylglycerols, diacylglycerols and sterols/sterol esters.
Dietary fat has six important functions:
*As a source of energy
*For cell structure and membrane functions
*For metabolism
*As a source of essential fatty acids for cell structures and prostaglandin synthesis
*As a vehicle for oil-soluble vitamins
*For control of blood lipids
In addition, fat contributes to the palatability of food and is important in cooking and food processing.
The basic units of fats are fatty acids and glycerol. The most common dietary fatty acids have been subdivided into three group according to the degree of unsaturation;
*Saturated fatty acids (SFA) have no double bonds,
*Monounsaturated fatty acids (MUFA) have one double bond
*Polyunsaturated fatty acids (PUFA) have two or more double bonds.
Fatty acids are carboxylic acids carboxylic acids with mostly long hydrocarbon unbranched aliphatic (non-aromatic) chains ranging from 4 to 36 carbons with hydrogens attached. Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula C(=O)OH, usually written -COOH or -CO2H.
The most common saturated fatty acid in animals, plants and microorganisms is palmitic acid (16:0). Stearic acid (18:0) is a major fatty acid in animals and some fungi, and a minor component in most plants.
Glycerol is a water-soluble compound that can bind up to three fatty acids. When one fatty acid is attached to a glycerol the compound is called a monoglyceride. When two fatty acids are attached to a glycerol the compound is called a diglyceride.
Functions of dietary fats
