Unsaturated Fat
A fat containing one or more carbon–carbon double bonds in its fatty acid chains.
Unit
Dimensionless
In depth
Cis double bonds introduce a permanent kink that prevents close packing, lowering the melting point and making these fats liquid oils. They decolourise bromine water, and partial hydrogenation to harden them produces trans fats, which behave nutritionally like saturated ones.
Examples in the real world
Olive oil as monounsaturated; sunflower oil as polyunsaturated; margarine made by hydrogenating vegetable oil.