chapter  10
Analysis of Neutral Lipids: Triacylglycerols
Pages 38

Triacylglycerols (TAGs) are complex molecules pre-

sent in all oils and fats. They mainly serve as energy

stores, but they are also employed as carriers of fatty

acids within aqueous solutions such as blood. TAGs

are made up of three fatty acids, attached to a glyc-

erol backbone by an ester linkage. The wide variety of

fatty acids that may attach to the glycerol back-

bone generates the large diversity of TAGs that can

be found. The fat stores of both plant and animal

organisms are formed by mixtures of TAGs, the fatty

acids containing from four to 36 carbon atoms, with

up to six double bonds. Each of these fatty acids are

combined in triplets to form TAGs that share very

similar physicochemical properties, thus making their

separation and analysis difficult. The length of the hydrocarbon chains of the fatty

acids and the location of the double bonds within the

TAG molecule is ordered and determines the spatial

configuration, and therefore, the physical properties

of the molecule. TAGs that contain a higher proportion

of unsaturated fats and fewer carbon atoms are

more polarized. Regardless of the saturated fatty

acids (SFAs), most of the monounsaturated fatty

acids (MUFAs) have the double bond situated between

carbons C9 and C10 (9). With respect to the poly-

unsaturated fatty acids (PUFAs), the double bond

is often located between carbons C12 and C15. These

double bonds are not naturally conjugated, but rather

a methyl group normally remains between them.