Everyone knows oils and fats as an ingredient
of daily food or perhaps as a raw material or soap making.
But only a few people know them as a group of organic compounds
called 'Fatty Acids'. Fatty Acids, in their turn, are formed
by union of several carbon atoms in a straight chain with
hydrogen and oxygen atoms.
A single chain may contain anywhere from
6 to 24 carbon atoms, but the common one are 12, 14, 16, 18
and 20 carbon chains. A fatty acid is said to be saturated
when all the carbon atoms are combined with hydrogen to their
full capacity. They are said to be unsaturated when the addition
of hydrogen. Higher the unsaturation, lower is the melting
point of fatty acid. As such, many oils containing large amounts
of unsaturated fatty acids in chemical combination, remain
as liquids at normal temperature. Those which contain lesser
amounts of unsaturated acids exist as solid or semi-solid
fats at normal temperatures.
A liquid oil can be converted to a required
degree of hardness by reducing its unsaturation by controlled
reaction with hydrogen. Vanaspati is a product obtained by
such controlled hydrogenation of edible liquid oils (called
`soft oils' in the Industry), so that its hardness consistency
and grainy appearance resemble natural Ghee. The addition
of hydrogen to an oil occurs when the hydrogen gas is brought
into contact with the oil at higher temperatures in the presence
of metallic Nickel Catalyst prepared under controlled conditions.
In practice, however, the process is not as simple. Several
steps are involved in the process as described in succeeding
paragraphs.
