Configuration of fatty acids

Within unsaturated fatty acids the carbon atoms on either side of a double bond can occur in a cis- or trans-configuration.

Cis-configuration: the adjacent carbon atoms are on the same side of the double bond.

Trans-configuration: the adjacent carbon atoms are on opposite sides of the double bond.

C18:2 (n-6)ct C18:2- trans Δ 9,cis Δ 12

Two trans-bonds

Trans fatty acids in our food mainly originate from two different sources: (1) industrially produced partially hydrogenated oils used in frying fats and margarines, and (2) ruminant fats in dairy and meat products. A diet high in trans fatty acids is associated with an increased risk of coronary heart disease.

Three cis-bonds

C18:3 all-cis Δ 9,12,15

Two cis-bonds

C18:2- all-cis Δ 9,12

One cis-bond

C18:1- cis Δ 9