ESSENTIAL OILS

ESSENTIAL OILS

These are volatile oils that occur mostly in

glands known as oil glands. They may be

found in different combinations and

Concentrations in the different parts of a plant.For example orange flowers Contain

their oWn distinctive oil known as Neroli oil,

Rose and dasmine oil are produced from

llowersS. Lemon grass oil on the other hand is

extracted from leaves and stems ol a lemon-

scented grass Cymbopogon spp. e

Cinnamon oil is obtained from the bark, while

Sandal wood, pine and cedar wood oll are

extracted from the wood of the trees. Orange

peels (rind) produces citrus oil.

Essential oils are mostly liquid and have

aromatic fragrance.

Essential oils differ from fatty oils in their

chemical compositions, as well as in being

volatile. They are soluble in water.

 

4.6.1 METHODS OF EXTRACTING ESSENTIAL

OLS: 12H6

There are various methods used to extract

essential oils. s

These include:

 

1. Expression

Expression is a cold-pressed method of

extraction of essential oils. It is mostly used in

the extraction of citrus essential oils such as

orange, grapelruit, lime and lemon essential

Ofls.

The ciLrus fruit is first placed in a device and

TOtated. There are spikes on the side of the

device puncturing the skin of the fruit and thus, the oil cells. When the oil cells rupture

essential oils is drained and collected for use

 

2. Enfleurage

This is achieved by spreading flowers thickly

between shallow trays greased on both sides

with purified fat, or in cloths soaked in Olive

oil, and left to impart their fragrance.

flowers are removed and replaced with fresh

ones every feW days until the fat or oll has

become saturated. The essential oil is then

extracted with

Enfleurage is a very expensive and labor

intensive way of extracting essential oils and

as such it is seldom used.

3. Steam distillation: This involves heating

of plant material by forcing steam through it

under pressure. Tiny particles of essential ofl

are vapourized and carried away in the steam

which collects in a cardeneer. Once cool

naving Separated, the oil can be skinned from

 

The

 

alcoholic solvent.

 

an

 

the surface of the water which has formed

 

Maceration: In maceration method of

extraction, batches of fresh flowers are soaked

in wamm fat for several days until the cell

membranes rupture and the Tat becomes

impregnated with their essential oils. Then.

the oil is drained and decanited, effectiveiy

collecting the essential oils.

 

the use of heat. Plant materials are kept

solvent e.g. Petroleumn ether and is then

distillation. The final extraction method of

 

This method avoids

kept

 

5. Solvent extraction.

constantly immersed in alcohol or volatile

1stilled to leave the oil behind by lractional

 

CSsential oils is solvent extraction. With this

Imethod, the essential oils are removed using

Solvents. This method is best used to extract

essential oils with a very low oil yield.

 

4.6.2 CLASSIFICATION OF ESSENTLAL OILS

Essential oils could be grouped for their

perfumes, flavours medicinal values and

other industrial uses.

 

1. PERFUMERY ESSENCES;

Perfumes have been in widespread use

 

for

 

ages. The most valuable perfumes are

 

combinations of several essential oils

Perfumes also contain fixatives, which are

substances that are less volatile than the oil

and which delay evaporation. Perfumes mna

be

 

be of plant or animal origin. Example=

include:

 

osM

 

Rose oil is the

 

Rosa gallica

 

Rose oil

 

essential oil exracted from the petals a

various types ol rose plant. Rose oil can b-

 

extracted Usingsteam distillation orb

Stean

solvent extraction. Extraction by Stean

 

distillation. produees an oil called rose Otto or lattar of roses while extraction by Solvent

extraction, results in an oil called rose

absolute.

 

Rose Otto is usually dark olive-green in color

and will form white crystals at normal room

temperature which disappear when the oil is

gently warmed. The essence has a very strong

odor, but is pleasant when diluted and used

-for periume. Rose absolute is a deep reddish

brown with no crystals. Due to the low

temperatures in this process, the absolute

may be more faithful to the scent of the fresh

rOSe than the Otto.

 

Bulgaria is the major producer of rose oil in

the world. Other producers are Morocco, Iran,

 

Turkey and China.

 

Rose oil is the most important and expensive

perfume oil.

 

 

 

 

Updated: February 9, 2020 — 7:09 pm

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