Extraction Technologies For Medicinal And Aromatic Plants - Unido

4 HYDROLYTIC MACERATION, EXPRESSION AND COLD FAT EXTRACTION
4.3.1.2 Ecuelle Process
This process was common in the south of France. Ecuelle consists
of a shallow bowl of copper with a hollow central tube with which it
forms a sort of funnel. The bowl is equipped with large brass nails with blunt
ends, on which the fruit is rolled by hand with some pressure until the entire
surface of fruit yields its oil. The oil and aqueous cell contents drain into the
central tube where they are separated by decantation. The yield is only 20%
of the total oil present in the peel.
These methods were quite laborious and, with the advance of
technology, machines have been invented to do them. Nowadays, rinds are
extracted for oil using centrifugal force.
4.3.1.3 Hand Machine
For expression, the peel is placed in a hollow sponge attached
with other sponges to a plate actuated by the lever and fi xed below with
additional sponges to the base. The sponge is fi tted with a funnel through
which oil and aqueous material pass to the receiving vessel. The part that
comes in contact with oil is made of brass or bronze.
4.3.1.4 Sfumatrici and Pelatrici
The machines that treat only the peel after removal of juice
and pulp are called sfumatrici, while those that process the whole fruit are
known as pelatrici.
4.3.1.4.1 Special Sfumatrice
This is a specially designed roller type machine in which each
peel is bent to expel the maximum quantity of oil. Not much pressure is exerted
to expel other contents of the cells. The emulsion is collected and fi ltered
through wool or sponges to yield oil and water. A number of sfumatrici
have been developed and were in use in many countries.
In expression using sfumatrici, two approaches are used. In
the fi rst approach (used by Ramino Sfumatrice), only the peel is treated, so
halving the fruit, removing the pulp and expressing the peel are the steps
involved. In the second approach, the oil is extracted by either puncturing
the peel glands or cutting a superfi cial layer of peel to expose the oil glands;
this is followed by washing away the oil with a spray of water.
In whole fruit extraction with a rasping machine, the whole fruit
is crushed and oil is subsequently separated from the aqueous phase (juice
and cell liquid). As citrus peel oil is a byproduct of the citrus juice industry,
both the oil and juice are extracted subsequently, e.g. in a rotatory juice
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