Functional properties of food lipids
Chemically, fats and oils, as you may already know by now, are a combination of glycerol and fatty acids. The glycerol molecule has three separate points, where a fatty acid molecule can be attached. Physically, fats and oils differ in that fats are solid and oils are liquid at room temperature. You learnt earlier that the different properties are to a large extent determined by the fatty acid composition and the extent of saturation or unsaturation present. These aspects are identified by the carbon chain length and the number and position of double bonds for the individual fatty acids and their position of the glycerol. Generally, solid fats indicated by a dominance of saturated fatty acids and liquid oils, are an evidence of a high level of unsaturated fatty acids.
Carbon chain lengths of fatty acds in edible oils and fats vary between 4 and 24 carbon atoms with up to three double bonds. The most prevalent saturated fatty acids are lauric (C-12:0), myristic (C-14:0), palmitic (C-16:0), stearic (C-18:0), arachidic (C-20:0), behenic (C-22:0) and lignoceric (C-24:0). The most important monounsaturated fatty acids are oleic (C-18:1) and erucic (C-22:1). The polyunsaturated fatty acids are linoleic (C-18:2) and linolenic (C-18:3).