Page 49 - phytochemistry I - PharmD Clinical

Disadvantages of the distillation method:
1-The high temperature in the presence of water during distillation induce
hydrolysis of esters and removal of water from tertiary alcohols.
2-Volatile amines and volatile degradation products of carbohydrates
(furfural) pass over during distillation and contaminate the V.O.

3- Loss of water soluble components of V.O.
The distillation water (in the oil separator) contains small amounts of
dissolved volatile oil and is often returned to the distillation still in order to
recover the dissolved oil. This process is called Cohobation (Redistillation
of water).

Used for volatile oils:
 Cannot be distilled without decomposition (sensitive to heat,
thermolabile).
 Found in large amount in oil - glands just below the surface in the
peel (rind). Generally, they are obtained by expressing the rind of
the fresh fruit. ex. oil of orange and lemon.

a) The sponge method:
The citrus fruit is washed, cut into halves. and the juicy part is
removed. The rind is turned inside out (squeezed) when secretion
gland rupture and the oil collected by means of the sponge, until the

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