Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev

EXTRACTION TECHNOLOGIES FOR MEDICINAL AND AROMATIC PLANTS
The number of extractors has to be synchronized with the number of solvent
washes.
1.3.2 Absolutes
Concretes are not widely used in perfumery in their native
form but are generally converted into an alcohol-soluble volatile concentrate
known as an absolute, i.e. they have to be extracted with alcohol.
To make an absolute, the concrete is mixed with absolute alcohol
and agitated thoroughly in a vessel with an agitator. During agitation,
the temperature is kept at 40°-60° C and the concrete is immersed in the
solution. The solution is cooled down to -5° to -10° C to precipitate out the
wax, since waxes are normally insoluble in alcohol below -1° C. The precipitated
wax is removed by passing the solution through a rotary fi lter. The
fi ltrate from the rotary fi lter is pumped into a primary evaporator, where it is
concentrated to about 10% alcohol content. Finally, the concentrated extract
is pumped into an agitating-type evaporator, where the alcohol is carefully
removed under high vacuum.
1.3.3 Resinoids
Resinoid is an extract of naturally resinous material, made with
a hydrocarbon solvent. Resinoids are usually obtained from dry materials.
The extraction process is same as that of concrete production, except that
perforated discs are not used for stacking the material; instead powder from
dry plant material is fed into the extractor.
1.3.4 Pomades
Pomades are obtained by a process known as enfl eurage,
which is a cold fat extraction method. The fat is spread out on glass plates
contained in wooden frames, leaving a clear margin near the edges. The
absorptive surface of the fat is increased by surface grooves made with a
wooden spatula.
Fresh fl owers are spread out on the surface of the fat and the
frames are stacked in piles. After the perfume oils have been absorbed from
the fl owers, the spent fl owers are removed by hand. Fresh fl owers are again
spread on the fat surface. This is repeated until the fat surface is completely
enriched with perfume oils. The pomade so obtained is ready for cold alcoholic
extraction.
1.3.5 Essential Oils
Essential oils are used in a wide variety of consumer goods such
as detergents, soaps, toilet products, cosmetics, pharmaceuticals, perfumes,
35