Generally speaking, fats
are made up of a fraction (approx. 90-99%) that is glyceridic in nature
, and include a considerable number of microcomponents: the non glyceridic
fraction (0.4-5%, which rises in certain oils to the decidedly higher value of 12%).
The glyceridic fraction is made up of triglycerides
. The triglycerides, diglycerides and monoglycerides present a molecule of glycerol
to which molecules of fatty acid (three, two or one, respectively) bind.
According to their origin, we may distinguish between oils on the basis of the fatty acids that are present in each and every drop
All fatty acids are made up of a chain of carbon atoms
to which oxygen and hydrogen are bound. We may distinguish between fatty acids on the basis of the number
of carbon atoms present. The acids include butyric
acid, with four carbon atoms (typical in butter), capric
acid (abundant in olive oil), linoleic
acid, and linolenic
acid, as well as long-chain fatty acids such as montanic
acid, with twenty-eight carbon atoms.
The carbon atoms that form the chains of fatty acids may be linked the one to the other by single bonds
or double bonds
. Fatty acids may be grouped in three separate categories on the basis of the presence, or absence, of double bonds in the chain of carbon atoms.
The absence of double bonds
is associated with the presence of saturated fats
, particularly abundant in fats of animal origin. The presence of merely one double bond
indicates the presence of monounsaturated fatty acids
, such as oleic acid. The presence of two or more double bonds
in the chain of carbon atoms indicates the presence of polyunsaturated acids
(typical in seed oils).
Find out more about fatty acids