Cholesterol is an optically active unsaturated monohydric waxy alcohol having an eight-carbon atom side chain which is completely saturated, a double bond at the 5th carbon and
a hydroxyl group at 3rd carbon. It is these 3 characteristic features of the molecule which
give it the properties it exhibits and, any alteration would lead to its differing p,hysiclogical
behaviour.
The bulk of commercial cholesterol supply is prepared from the lanolin derivatives, lanolin
alcohols which constitute the major portion of the unsaponifiable portion of the lanolin.
Cholesterol is applied Mainly in the fields of cosmetics, intermediate material to vitamin D3
and liquid crystal, and dietary ingredient for prawn cultivation.
Cholesterol possesses some hydrophilic properties and retains an optimum amount of water
in emulsified form in the outer layer of the skin and skin lipids, this help in keeping the skin
supple. A deficiency ofthis moisturing lipid results in excessive dehydration with consequent
brittleness and superficial, cracking of the horny layer - a condition which is aggravated by
adverse weather conditions. Apart from moisturing, cholesterol acids can also be used in
modifying the occulusiveness of fatty and oil films.
There are studies indicating the necessity of cholesterol in diets for normal growth and
survival of prawn. The prawn receiving the diet supplement with cholesterol grew normal,
the survival rate and growth rate were 86 - 95% and 56 - 98% respectively. However the
growth rate of prawn receiving the sterol free diet was poor (22 - 64%).
Many experiments reveal that, the requirement for cholesterol was about 0.5 to 1 .0%. The
survival rates of prawn fed the diet containing other sterols (like ergosterol, stigmasterol,
etc) as compared to the prawn fed the cholesterol diet, the growth rates of these sterols were
inferior to cholesterol. This suggest that the effectiveness of cholesterol in improving the
growth and the survival of prawn.