Essential oils are volatile (quickly evaporating) aromatic fluids extracted from plants through steam distillation, or in the case of citrus fruits through expression (or cold pressing) of the rind to obtain an oil that retains a juicy, fresh fruit scent. Various extraction methods are used in the manufacture and extraction of essential oils, and the method used is normally dependant on what type of botanical material is being used.

1. EXTRACTION OF OILS
Dr. Asra Hameed
Pharm.D (JUW)
asra_hameed1@hotmail.com

2. Essential oil

3. What is an essential oil?
Essential oils are volatile (quickly
evaporating) aromatic fluids extracted from
plants through steam distillation, or in the
case of citrus fruits through expression (or
cold pressing) of the rind to obtain an oil that
retains a juicy, fresh fruit scent.
These “oils” are found in tiny sacs or
globules within the plant, are highly
aromatic, and although referred to as oils,
are not fats.
 Essential oils can be extracted from the
leaves, stems, roots, bark, flower or resin
from a wide variety of botanicals, and can
be used for fragrance as well as for their
therapeutic benefits.

4. Extraction of essential oils
 Various extraction methods are used in
the manufacture and extraction of
essential oils, and the method used is
normally dependant on what type of
botanical material is being used.

5. EXTRACTION METHODS

6. Extraction Methods
 Distillation & Extraction
 Absolutes
 CO2 Extracts
 Organic Extracts
 Resins

7. EXTRACTION METHODS
 Although steam distillation is the most well-
known technique for extracting essential
oil from plants, there are several other
methods that are used to remove and
concentrate the aromatic constituents
from plant materials.
 Here is a brief description of each method
and their influence on the
aromatherapeutic properties and
fragrance of the oil.

8. Distillation & Extracti

9. ESSENTIAL OILS
DISTILLATION & EXPRESSION
 Essential oils are produced in the cells of
aromatic plants and are held in specialized
glands.
 They are released from the plant and collected
(concentrated) most often through steam
distillation (and sometimes hydro or water
distillation or a combination thereof).
 Distillation is a method of separating
components based on differences in volatile
constituents in a heated mixture.
 Steam distillation involves bubbling steam
through the plant material.
 The temperature of steam is easy to control,
making it ideal for heat-sensitive essential oils.

10.  The essential oils contained in plants are
immiscible in water and have a higher boiling
point, allowing the essential oil to vaporize at a
lower temperature than it normally would on its
own.
 Other methods used to create pure essential
oils are dry or vacuum distillation,
dry/destructive distillation, and expression (for
citrus peels).
 Expression, also referred to as “cold pressed”, is
a method where oil is obtained by using high
mechanical pressure to literally squeeze the oil
from the plant material.
Essential Oils
Distillation & Expression

11. Absolutes

12. WHAT IS AN ABSOLUTE?
 Like essential oils, absolutes come from volatile,
aromatic fluids extracted from plants.
 Delicate flowers such as rose, jasmine and
orange blossom are oftentimes extracted as
absolutes to yield a higher percentage of oil
without using the heat that can damage the
petals during steam distillation.
 Absolutes differ from essential oils in that they
contain a higher density of colorants, waxes
and other constituents from the plant, making
the aroma highly concentrated and more true
to nature.
 They are solvent extracted, and since a trace
amount of solvent may be present they are not
used for therapeutic purposes, but instead, for
natural perfumery.

13. ABSOLUTES: SOLVENT EXTRACTION
 Absolutes are highly concentrated aromatic oils
extracted from plants using a solvent method.
 The multi-step process includes first extracting the
aromatic oil from the plant material with a solvent such
as hexane.
 After the hexane is removed what is left behind is a
waxy substance called a concrete.
 The aromatic oils are then extracted from the concrete
with ethyl alcohol, and after the ethyl alcohol is
removed, the remaining substance is an absolute – an
oil with an aroma close to the plant from which it came.
 An absolute is the most concentrated form of fragrance
and highly regarded in natural perfumery.
 Absolutes differ from essential oils in that they contain
not only essential oil, but also a higher density of
coloring, waxes and other constituents from the plant.
 In addition, they usually contain a small percentage of
alcohol remaining from the second phase of the
extraction process (typically up to 2 or 3 percent).

14. CO2 EXTRACTS
WHAT IS A CO2
EXTRACT?

15. WHAT IS A CO2 EXTRACT?
 Although the method of extraction is similar to
an absolute, CO2 extracts are more
comparable to essential oils in that they
contain a myriad of therapeutic benefits
without any trace of solvent left behind.
 Instead of hexane, they are extracted using
CO2 (carbon dioxide) gas under pressure at
ambient temperatures.
 Under normal atmospheric conditions CO2 is
a gas, but in the presence of high pressure it is
compressed until it has the density of a liquid
and becomes “supercritical” carbon dioxide –
neither a gas nor a liquid.
 It is while in this supercritical phase that CO2
acts as a “solvent” to extract aromatic oil from
plants.

16.  The beauty of CO2 extraction is that once the
oil is extracted from the plant material, the CO2
is simply returned to its gaseous state and
quickly and completely dissipates.
 The advantage of CO2 extraction over steam
distillation is that since there is very low heat
during the process a greater amount of
valuable constituents can be retained.
 Typically, they have an aroma closer to the
natural plant, especially those oils with spicy
notes.
 Although there are some advantages of CO2
extraction over steam distillation, there are oils,
such as Patchouli, where steam distillation
produces a richer, more full-bodied oil.
What is a CO2 Extract?

17. CO2 EXTRACTS: SOLVENT
EXTRACTION

18. CO2 EXTRACTS:
SOLVENT EXTRACTION CO2 extracts display some of the characteristics of both essential
oils and absolutes.
 Like essential oils, they contain many beneficial therapeutic
properties. But unlike absolutes, they are not solvent extracted.
 Instead of using a solvent like hexane, they are extracted using
CO2 (carbon dioxide) gas under pressure at ambient
temperature.
 Under normal atmospheric conditions CO2 is a gas, but when
highly compressed it becomes supercritical – neither a gas nor a
liquid.
 Supercritical CO2 is an excellent organic solvent that can be
used to extract aromatic oils from plants.
 The beauty of CO2 extraction is that once the oil is extracted
from the plant material, the CO2 returns to its gaseous state by
lowering its pressure, allowing the gas to quickly and completely
dissipate.
 Depending on the pressure used, a “select” or “total” extract will
result.
 Select extracts are created at lower pressures, and are more
similar to essential oils in that they are usually fully mobile liquids,
and essential oil constituents make up the vast majority of the
extract.

19. CO2 EXTRACTS:
SOLVENT EXTRACTION Total extracts are created using higher pressures and contain
more constituents of the plant, can be thicker or waxier, and
more closely resemble the constituents of the whole plant
rather than just the essential oil fraction of the plant.
 Because of the purity of CO2 extracts and since they display
some very favorable characteristics not found in essential oils,
CO2 extracts are primarily used by the food, body care, and
herbal industries, yet CO2 extracts are also excellent for
aromatherapy and natural perfumery.
 This extraction technique (more accurately called
supercritical CO2 extraction) is a relatively new and
expensive technology that is more efficient in some ways
than steam distillation, because the process has the ability to
capture a broader spectrum of the plant components, giving
a fragrance more true to the original plant material without
the use of chemical solvents.
 Other benefits are that the extraction process happens at
lower temperatures than steam distillation and that carbon
dioxide is nontoxic, odorless, and is easily removed from the
extracted oil at the end of the process.

20. Organic Extracts

21. WHAT IS AN ORGANIC
EXTRACT?
 Organic extracts are made using
modernized technology similar to the
ancient method of enfleurage.
 The extraction process uses only
certified organic solvents such as fixed
oils and alcohol to coax the aromatic
essence out of the plant material.
 The resulting bio-available essence,
extracted without added heat,
captures the intricate aroma of the
original plant material.

22. ORGANIC EXTRACTS
 Rose, Jasmine, Carnation, Orange Blossom,
and Tuberose.
 These oils are best used for body care and
aromatherapy due to the ‘aliveness’ of the
essences.
 However, natural perfumers who wish to create
organic perfumes will also love these oils.
 This new technology, for the first time allows
Jasmine oil to be used for true aromatherapy
purposes, whereas previously it had only been
available as an absolute and therefore had not
been recommended for therapeutic
applications.

23. Resins

24. RESINS & OTHER TYPES OF “OILS”
 We carry a few other types of natural aromatic oils that
have been extracted using other processes.
 These include natural exudates and resins (or resinoids).
 These aromatic essences are collected from the resin
that oozes out of the bark of trees when the trees are
tapped (like rubber trees or maple trees [for maple
syrup]).
 Another type of aromatic oil we offer comes from the
traditional destructive distillation method that gives rise
to Fossilized Amber Oil.
 In destructive distillation, the starting material (such as
Benzoin resin) is super-heated and cooked until an oil
substance is obtained from the solid starting material.
 Thus, oil can be obtained from something that didn’t
really have oil in it in the first place.

25. CONCLUSION