Malcolm G Stephen 2003 Fats and Oils © Malcolm G Stephen 2004

Malcolm G Stephen 2003 Fats and Oils Naturally occurring Animal fatVegetable oilMarine oil lard suet sunflower oil coconut oil cod liver oil whale oil

Malcolm G Stephen 2003 Fats and Oils glycerol Systematic name is propane-1,2,3-triol Fats and oils are built from an alcohol with three -O-H groups.

Malcolm G Stephen 2003 Fats and Oils Stearic acid Systematic name is octadecanoic acid The other components of fat molecules are carboxylic acids such as

Malcolm G Stephen 2003 Fats and Oils Fats and oils are ESTERS of glycerol and long chain carboxylic acids

Malcolm G Stephen 2003 Fats and Oils The structural formula shown above suggests that the fat molecule is shaped like an E, but the molecule is actually shaped more like this- Removal of water in the condensation reaction gives a fat -

Malcolm G Stephen 2003 Fats and Oils Fats are mainly built from carboxylic acids with C-C single bonds. Stearic acid in beef fat notice that with only C-C bonds the molecule is “straight”

Malcolm G Stephen 2003 Fats and Oils Oils have some C=C bonds in the carboxylic acids from which they are made. Oleic acid in olive oil notice that the shape of the molecule is distorted by the C=C bond

Malcolm G Stephen 2003 Fats and Oils Oil Fat Double bonds in oil make the molecule less compact. Less tightly packed molecules make oils liquid. Fat molecules pack together tightly, making fats solid at room temperature.

Malcolm G Stephen 2003 Fats and Oils Converting C=C bonds to C-C will change oils into fats. This is done by addition of hydrogen (hydrogenation) using a nickel catalyst. in oil in fat

Malcolm G Stephen 2003 Fats and Oils © Malcolm G Stephen 2004