 |
| A bottle of Italian olive oil |
Olive oil
From Wikipedia, the free encyclopedia
Not to be confused with the cartoon character
Olive Oyl.
is a
fat obtained from the
olive (the fruit of
Olea europaea; family
Oleaceae), a traditional tree
crop of the
Mediterranean Basin. The oil is produced by pressing whole olives.
It is commonly used in
cooking,
cosmetics,
pharmaceuticals, and
soaps and as a
fuel for traditional
oil lamps. Olive oil is used throughout the world, but especially in the
Mediterranean countries and, in particular, in
Portugal,
Spain,
Italy and
Greece, which has the highest consumption per person.
History
Early cultivation
The olive tree is native to the Mediterranean basin; wild olives were collected by
Neolithic peoples as early as the 8th millennium BC.
The wild olive tree originated in
Asia Minor or in ancient
Greece.
It is not clear when and where olive trees were first domesticated: in Asia Minor in the 6th millennium, along the
Levantine coast stretching from the
Sinai Peninsula and
Israel to modern
Turkey in the 4th millennium, or somewhere in the
Mesopotamian Fertile Crescent in the 3rd millennium.
Archeological evidence shows that olives were turned into oil by 4500 BC by
Canaanites in present-day
Israel.
Until 1500 BC, eastern coastal areas of the Mediterranean were most
heavily cultivated. Evidence also suggests that olives were being grown
in Crete as long ago as 2,500 BC. The earliest surviving olive oil
amphorae
date to 3500 BC (Early Minoan times), though the production of olive is
assumed to have started before 4000 BC. Olive trees were certainly
cultivated by the
Late Minoan period (1500 BC) in Crete, and perhaps as early as the
Early Minoan.
The cultivation of olive trees in Crete became particularly intense in
the post-palatial period and played an important role in the island's
economy, as it did across the Mediterranean.
Recent genetic studies suggest that species used by modern
cultivators descend from multiple wild populations, but a detailed
history of domestication is not yet understood.
Production and trade
 |
Ancient oil press (Bodrum Museum
of Underwater Archaeology,
Bodrum, Turkey) |
Olive trees and oil production in the Eastern Mediterranean can be traced to archives of the ancient city-state
Ebla (2600–2240 BC), which were located on the outskirts of the
Syrian city
Aleppo.
Here some dozen documents dated 2400 BC describe lands of the king and
the queen. These belonged to a library of clay tablets perfectly
preserved by having been baked in the fire that destroyed the palace. A
later source is the frequent mentions of oil in
Tanakh.
Dynastic
Egyptians before 2000 BC imported olive oil from Crete, Syria and
Canaan
and oil was an important item of commerce and wealth. Remains of olive
oil have been found in jugs over 4,000 years old in a tomb on the island
of
Naxos in the
Aegean Sea.
Sinuhe, the Egyptian exile who lived in northern Canaan about 1960 BC, wrote of abundant olive trees.
Besides food, olive oil has been used for religious
rituals,
medicines, as a
fuel in
oil lamps,
soap-making, and skin care application. The Minoans used olive oil in religious ceremonies. The oil became a principal product of the
Minoan civilization, where it is thought to have represented wealth. The Minoans put the pulp into
settling tanks and, when the oil had risen to the top, drained the water from the bottom.
[citation needed] Olive tree growing reached
Iberia and
Etruscan cities well before the 8th century BC through trade with the
Phoenicians and
Carthage, then was spread into Southern
Gaul by the
Celtic tribes during the 7th century BC.
The first recorded oil extraction is known from the Hebrew Bible and took place during
the Exodus from Egypt, during the 13th century BC.
[citation needed]
During this time, the oil was derived through hand-squeezing the
berries and stored in special containers under guard of the priests. A
commercial mill for non-sacramental use of oil was in use in the tribal
Confederation and later in 1000 BC, the
fertile crescent,
an area consisting of present day Palestine, Lebanon, and Israel. Over
100 olive presses have been found in Tel Miqne (Ekron), where the
Biblical
Philistines also produced oil. These presses are estimated to have had output of between 1,000 and 3,000 tons of olive oil per season.
Many ancient presses still exist in the Eastern Mediterranean region,
and some dating to the Roman period are still in use today.
[citation needed]
 |
| Olive crusher (trapetum) in Pompeii (79 AD) |
Olive oil was common in
ancient Greek and
Roman cuisine. According to
Herodotus,
Apollodorus,
Plutarch,
Pausanias,
Ovid and other sources, the city of
Athens obtained its name because Athenians considered olive oil essential, preferring the offering of the goddess
Athena (an olive tree) over the offering of
Poseidon (a spring of
salt water gushing out of a cliff). The
Spartans and other Greeks used oil to rub themselves while exercising in the
gymnasia.
From its beginnings early in the 7th century BC, the cosmetic use of
olive oil quickly spread to all of Hellenic city states, together with
athletes training in the nude, and lasted close to a thousand years
despite its great expense. Olive trees were planted in the entire Mediterranean basin during evolution of the
Roman republic and
empire. According to the historian
Pliny, Italy had "excellent olive oil at reasonable prices" by the 1st century AD, "the best in the Mediterranean", he maintained.
 |
The Manufacture of Oil,
16th century engraving by J. Amman |
The importance and antiquity of olive oil can be seen in the fact that the English word
oil derives from c. 1175,
olive oil, from Anglo-Fr. and O.N.Fr.
olie, from O.Fr.
oile (12c., Mod.Fr.
huile), from L.
oleum "oil, olive oil" (cf. It.
olio), from Gk.
elaion "olive tree", which may have been borrowed through trade networks from the Semitic Phoenician use of
el'yon meaning "superior", probably in recognized comparison to other vegetable or animal
fats available at the time.
Robin Lane Fox suggests that the Latin borrowing of Greek
elaion for oil (Latin
oleum)
is itself a marker for improved Greek varieties of oil-producing olive,
already present in Italy as Latin was forming, brought by
Euboean traders, whose presence in Latium is signaled by remains of their characteristic pottery, from the mid-8th century.
Varieties
There are many different olive varieties or
olives,
each with a particular flavor texture and shelf-life that make them
more or less suitable for different applications such as direct human
consumption on bread or in salads, indirect consumption in domestic
cooking or catering, or industrial uses such as animal feed or
engineering applications.
Production and consumption
Spain produces 43.8% of world production of olive oil.
[15] 75% of Spain's production comes from the region of
Andalucía, particularly within
Jaén province,
although other regions also produce excellent oil. Although Italy is a
net importer of olive oil, it still accounts for 21.5% of the world's
production. Major Italian producers are known as "Città dell'Olio", "oil
cities"; including
Lucca,
Florence and
Siena, in
Tuscany. However the largest production is harvested in
Puglia and
Calabria.
Greece accounts for 12.1% of world production and Syria for 6.1%, as
third and fourth largest producers in the World. Portugal accounts for
5% and its main export market is
Brazil. Morocco is the world's sixth largest producer.
Australia now produces a substantial amount of olive oil. Many
Australian producers only make premium oils, while a number of corporate
growers operate groves of a million trees or more and produce oils for
the general market. Australian olive oil is exported to Asia, Europe and
the United States.
In North America, Italian and Spanish olive oils are the best-known, and top-quality
extra-virgin
oils from Italy, Spain, Portugal and Greece are sold at high prices,
often in "prestige" packaging. A large part of U.S. olive oil imports
come from Italy, Spain, and Turkey. The U.S. imported 47,800,000 US
gallons (181,000 m
3) of olive oil in 1998, of which 34,600,000 US gallons (131,000 m
3) came from Italy.
Turkey, New Zealand, The Republic of South Africa,
Argentina
and Chile also produce extra virgin olive oil.
Olive orchards in Arizona, California, and Texas are producing olive
oil that is appearing on U.S. grocery market shelves alongside the
Mediterranean olive oils.
Major producers of olive oil in the world between 2000 and 2009
| Country |
2000 (tonnes) |
% |
2005 ( tonnes) |
% |
2009 ( tonnes) |
% |
 Spain |
962,400 |
38.2% |
819,428 |
32.1% |
1,199,200 |
41.2% |
 Italy |
507,400 |
20.1% |
671,315 |
26.3% |
587,700 |
20.2% |
 Greece |
408,375 |
16.2% |
386,385 |
15.1% |
332,600 |
11.4% |
 Syria |
165,354 |
6.6% |
123,143 |
4.8% |
168,163 |
5.8% |
 Tunisia |
115,000 |
4.6% |
210,000 |
8.2% |
150,000 |
5.2% |
 Turkey |
185,000 |
7.3% |
115,000 |
4.5% |
143,600 |
4.9% |
 Morocco |
40,000 |
1.6% |
50,000 |
2.0% |
95,300 |
3.3% |
 Algeria |
30,488 |
1.2% |
34,694 |
1.4% |
56,000 |
1.9% |
 Portugal |
25,974 |
1.0% |
31,817 |
1.2% |
53,300 |
1.8% |
 Argentina |
10,500 |
0.4% |
20,000 |
0.8% |
22,700 |
0.8% |
 Lebanon |
5,300 |
0.2% |
6,800 |
0.3% |
19,700 |
0.7% |
 Jordan |
27,202 |
1.1% |
17,458 |
0.7% |
16,760 |
0.6% |
 Libya |
6,000 |
0.2% |
7,900 |
0.3% |
15,000 |
0.5% |
| TOTAL |
2,518,629 |
100.0% |
2,552,182 |
100.0% |
2,911,115 |
100% |
| FAO |
Regulation
 |
| International Olive Council building |
The
International Olive Council
(IOC) is an intergovernmental organisation of states that produce
olives or products derived from olives, such as olive oil. The IOC
officially governs 95% of international production and holds great
influence over the rest. The EU regulates the use of different
protected designation of origin labels for olive oils.
The
United States is not a member of the IOC and is not subject to its authority, but on October 25, 2010, the
U.S. Department of Agriculture
adopted new voluntary olive oil grading standards that closely parallel
those of the IOC, with some adjustments for the characteristics of
olives grown in the U.S.
Additionally, U.S. Customs regulations on "country of origin" state
that if a non-origin nation is shown on the label, then the real origin
must be shown on the same side of the label and in comparable size
letters so as not to mislead the consumer.
Yet most major U.S. brands continue to put "imported from Italy" on the
front label in large letters and other origins on the back in very
small print.
"In fact, olive oil labeled 'Italian' often comes from Turkey, Tunisia, Morocco, Spain, and Greece." This makes it unclear what percentage of the olive oil is really of Italian origin.
Commercial grades
All production begins by transforming the olive fruit into olive paste by crushing or pressing. This paste is then
malaxed
(slowly churned or mixed) to allow the microscopic oil droplets to
agglomerate. The oil is then separated from the watery matter and fruit
pulp with the use of a press (traditional method) or
centrifugation (modern method). After extraction the remnant solid substance, called
pomace, still contains a small quantity of oil.
The grades of oil extracted from the olive fruit can be classified as:
- Virgin means the oil was produced by the use of mechanical means only, with no chemical treatment. The term virgin oil with reference to production method includes both Virgin and Extra-Virgin olive oil products, depending on quality (see next section).
- Lampante oil is olive oil extracted by virgin (mechanical) methods but not suitable as food; lampante
is Italian for "lamp", referring to the use of such oil for burning in
lamps. Lampante oil can be used for industrial purposes, or refined (see
below) to make it edible.
- Refined means that the oil has been chemically treated to
neutralize strong tastes (characterized as defects) and neutralize the
acid content (free fatty acids). Virgin olive oil (including the grades extra-virgin olive oil and virgin olive oil) therefore cannot contain any refined oil.
- Olive pomace oil means oil extracted from the pomace using solvents, mostly hexane, and by heat.
 |
| Italian label for "extra vergine" oil |
In countries that adhere to the standards of the International Olive Council (IOC), as well as in
Australia, and under the voluntary USDA labeling standards in the United States:
- Extra-virgin olive oil Comes from virgin oil production only,
and is of higher quality: among other things, it contains no more than
0.8% free acidity (see below), and is judged to have a superior taste,
having some fruitiness and no defined sensory defects. Extra-virgin
olive oil accounts for less than 10% of oil in many producing countries;
the percentage is far higher in the Mediterranean countries (Greece:
80%, Italy: 65%, Spain 30%).
- Virgin olive oil Comes from virgin oil production only, but
is of slightly lower quality, with free acidity of up to 1.5%, and is
judged to have a good taste.
- Refined olive oil is the olive oil obtained from virgin olive
oils by refining methods that do not lead to alterations in the initial
glyceridic structure. It has a free acidity, expressed as oleic acid,
of not more than 0.3 grams per 100 grams (0.3%) and its other
characteristics correspond to those fixed for this category in this
standard. This is obtained by refining virgin olive oils with a high
acidity level and/or organoleptic defects that are eliminated after
refining. Note that no solvents have been used to extract the oil, but
it has been refined with the use of charcoal and other chemical and
physical filters. Oils labeled as Pure olive oil or Olive oil are primarily refined olive oil, with a small addition of virgin-production to give taste.
- Olive pomace oil is refined pomace olive oil often blended with some virgin oil. It is fit for consumption, but may not be described simply as olive oil.
It has a more neutral flavor than pure or virgin olive oil, making it
unfashionable among connoisseurs; however, it has the same fat
composition as regular olive oil, giving it the same health benefits. It
also has a high smoke point, and thus is widely used in restaurants as
well as home cooking in some countries.
Retail grades in the United States from the USDA
As the United States is not a member, the IOC retail grades have no
legal meaning in that country, but as of October 25, 2010, the USDA
established new Standards for Grades of Olive Oil and Olive-Pomace Oil,
which closely parallel the IOC standards:
- U.S. Extra Virgin Olive Oil for oil with excellent flavor and odor and free fatty acid content of not more than 0.8 g per 100 g (0.8%);
- U.S. Virgin Olive Oil for oil with reasonably good flavor and odor and free fatty acid content of not more than 2 g per 100 g (2%);
- U.S. Virgin Olive Oil Not Fit For Human Consumption Without Further Processing is a virgin (mechanically-extracted) olive oil of poor flavor and odor, equivalent to the IOC's lampante oil;
- U.S. Olive Oil is an oil mix of both virgin and refined oils;
- U.S. Refined Olive Oil is an oil made from refined oils with some restrictions on the processing.
These grades are voluntary. Certification is available from the USDA on a fee-for-service basis.
Quantitative analysis can determine the oil's "acidity", which refers not to its chemical
acidity in the sense of
pH but as the percent (measured by weight) of
free oleic acid. This is a measure of the
hydrolysis of the oil's triglycerides: as the oil degrades, more fatty acids are freed from the
glycerides, increasing the level of free acidity and thereby increasing
hydrolytic rancidity. Another measure of the oil's chemical degradation is the
peroxide value, which measures the degree to which the oil is
oxidized (damaged by
free radicals, leading to
oxidative rancidity.
To classify it by taste, olive oil is judged by a panel of trained tasters in a
blind taste test. This is also called its
organoleptic quality.
Label wording
- Different names for olive oil indicate the degree of processing the
oil has undergone as well as the quality of the oil. Extra-virgin olive
oil is the highest grade available, followed by virgin olive oil. The
word "virgin" indicates that the olives have been pressed to extract the
oil; no heat or chemicals have been used during the extraction process,
and the oil is pure and unrefined. Virgin olive oils contain the
highest levels of polyphenols, antioxidants that have been linked with
better health.
- "Made from refined olive oils" means that the taste and composition
are chemically controlled, usually to improve lower quality oils. In Australia, Pure, Light and Extra-Light are terms introduced by manufacturers for refined oils to avoid labeling them as such. Standards Australia's
code of practice for olive oil now recognises these words as meaning
refined oil. Contrary to a common consumer belief, they do not have less
calories than Extra-virgin oil as implied by the names.
- Cold pressed or Cold extraction means "that the oil
was not heated over a certain temperature (usually 80 °F (27 °C)) during
processing, thus retaining more nutrients and undergoing less
degradation".
- First cold pressed means "that the fruit of the olive was crushed exactly one time-i.e., the first press. The cold refers to the temperature range of the fruit at the time it is crushed".
In Calabria (Italy) the olives are collected in October. In regions
like Tuscany or Liguria, the olives collected in November and ground
often at night are too cold to be processed efficiently without heating.
The paste is regularly heated above the environmental temperatures,
which may be as low as 10–15 °C, to extract the oil efficiently with
only physical means. Olives pressed in warm regions like Southern Italy
or Northern Africa may be pressed at significantly higher temperatures
although not heated. While it is important that the pressing
temperatures be as low as possible (generally below 25 °C) there is no
international reliable definition of "cold pressed".
Furthermore, there is no "second" press of virgin oil, so the term
"first press" means only that the oil was produced in a press vs. other
possible methods.
- PDO and PGI
refers to olive oils with "exceptional properties and quality derived
from their place of origin as well as from the way of their production".
- The label may indicate that the oil was bottled or packed in a
stated country. This does not necessarily mean that the oil was produced
there. The origin of the oil may sometimes be marked elsewhere on the
label; it may be a mixture of oils from more than one country.
- The U.S. Food and Drug Administration permitted a claim on olive oil
labels stating: "Limited and not conclusive scientific evidence
suggests that eating about two tablespoons (23 g) of olive oil daily may
reduce the risk of coronary heart disease."
Adulteration
The adulteration of oil can be no more serious than passing off
inferior, but safe, product as superior olive oil, but there are no
guarantees. It is guessed that almost 700 people died in 1981 as a
consequence of consuming
rapeseed oil adulterated with
aniline intended for use as an industrial lubricant, but sold as olive oil in Spain (see
toxic oil syndrome).
There have been allegations, particularly in Italy and Spain, that regulation can be sometimes lax and corrupt.
Major shippers are claimed to routinely adulterate olive oil and that
only about 40% of olive oil sold as "extra virgin" in Italy actually
meets the specification. In some cases,
colza oil (Swedish turnip) with added color and flavor has been labeled and sold as olive oil.
This extensive fraud prompted the Italian government to mandate a new
labeling law in 2007 for companies selling olive oil, under which every
bottle of Italian olive oil would have to declare the farm and press on
which it was produced, as well as display a precise breakdown of the
oils used, for blended oils.
In February 2008, however, EU officials took issue with the new law,
stating that under EU rules such labeling should be voluntary rather
than compulsory.
Under EU rules, olive oil may be sold as Italian even if it only contains a small amount of Italian oil.
Extra Virgin olive oil has strict requirements and is checked for
"sensory defects" that include: rancid, fusty, musty, winey (vinegary)
and muddy sediment. These defects can occur for different reasons. The
most common are:
- Raw material (olives) infected or battered
- Inadequate harvest, with contact between the olives and soil
In March 2008, 400 Italian police officers conducted "Operation
Golden Oil", arresting 23 people and confiscating 85 farms after an
investigation revealed a large-scale scheme to relabel oils from other
Mediterranean nations as Italian.
In April 2008, another operation impounded seven olive oil plants and
arrested 40 people in nine provinces of northern and southern Italy for
adding
chlorophyll to
sunflower and
soybean oil,
and selling it as extra virgin olive oil, both in Italy and abroad;
25,000 liters of the fake oil were seized and prevented from being
exported.
On March 15, 2011, the Florence, Italy prosecutor's office, working
in conjunction with the forestry department, indicted two managers and
an officer of Carapelli, one of the brands of the Spanish company Grupo
SOS (which recently changed its name to Deoleo). The charges involved
falsified documents and food fraud. Carapelli lawyer Neri Pinucci said
the company was not worried about the charges and that "the case is
based on an irregularity in the documents."
In February 2012, an alleged international olive oil scam occurred in
which palm, avocado, sunflower and other cheaper oils were passed off
as Italian olive oil.
Police said the oils were blended in an industrial biodiesel plant and
adulterated in a way to hide markers that would have revealed their true
nature. The oils were not toxic, however, and posed no health risk,
according to a statement by the Guardia Civil. Nineteen people were
arrested following the year-long joint probe by the police and Spanish
tax authorities, part of what they call Operation Lucerna.
Global consumption
Greece has by far the largest per capita consumption of olive oil worldwide, over 26 liters per person per year;
Spain and
Italy, around 14 l;
Tunisia,
Portugal,
Syria,
Jordan and
Lebanon, around 8 l.
Northern Europe
and North America consume far less, around 0.7 l, but the consumption
of olive oil outside its home territory has been rising steadily.
Global market
The main producing and consuming countries are:
| World |
3,269,248 |
100% |
100% |
0.43 |
| Spain |
1,487,000 |
45.5% |
20% |
13.62 |
| Italy |
548,500 |
16.8% |
30% |
12.35 |
| Greece |
352,800 |
10.8% |
9% |
23.7 |
| Syria |
177,400 |
5.4% |
3% |
7 |
| Morocco |
169,900 |
5.2% |
2% |
11.1 |
| Turkey |
161,600 |
4.9% |
2% |
1.2 |
| Tunisia |
160,100 |
4.9% |
2% |
5 |
| Portugal |
66,600 |
2.0% |
2% |
1.8 |
| Algeria |
33,600 |
1.0% |
2% |
7.1 |
| Others |
111,749 |
3.5% |
28% |
1.18 |
 |
| A cold press olive oil machine in Israel. |
Olive oil is produced by grinding olives and extracting the oil by
mechanical or chemical means. Green olives usually produce more bitter
oil, and overripe olives can produce oil that is rancid, so for good
extra virgin olive oil care is taken to make sure the olives are
perfectly ripened. The process is generally as follows:
- The olives are ground into paste using large millstones (traditional method) or steel drums (modern method).
- If ground with mill stones, the olive paste generally stays under
the stones for 30 to 40 minutes. A shorter grinding process may result
in a more raw paste that produces less oil and has a less ripe taste, a
longer process may increase oxidation of the paste and reduce the
flavor. After grinding, the olive paste is spread on fiber disks, which
are stacked on top of each other in a column, then placed into the
press. Pressure is then applied onto the column to separate the vegetal
liquid from the paste. This liquid still contains a significant amount
of water. Traditionally the oil was shed from the water by gravity (oil
is less dense than water). This very slow separation process has been
replaced by centrifugation, which is much faster and more thorough. The
centrifuges have one exit for the (heavier) watery part and one for the
oil. Olive oil should not contain significant traces of vegetal water as
this accelerates the process of organic degeneration by microorganisms.
The separation in smaller oil mills is not always perfect, thus
sometimes a small watery deposit containing organic particles can be
found at the bottom of oil bottles.
- In modern steel drum mills the grinding process takes about 20
minutes. After grinding, the paste is stirred slowly for another 20 to
30 minutes in a particular container (malaxation), where the microscopic
oil drops unite into bigger drops, which facilitates the mechanical
extraction. The paste is then pressed by centrifugation/ the water is
thereafter separated from the oil in a second centrifugation as
described before.
The oil produced by only physical (mechanical) means as described above
is called virgin oil. Extra virgin olive oil is virgin olive oil that
satisfies specific high chemical and organoleptic criteria (low free
acidity, no or very little organoleptic defects). A higher grade extra
virgin olive oil is mostly dependent on favourable weather conditions; a
drought during the flowering phase, for example, can result in a lower
quality (virgin) oil. It is worth noting that olive trees produce well
every couple of years so greater harvests occur in alternate years (the
year in-between is when the tree yields less). However the quality is
still dependent on the weather.
- Sometimes the produced oil will be filtered to eliminate remaining
solid particles that may reduce the shelf life of the product. Labels
may indicate the fact that the oil has not been filtered, suggesting a different taste. Unfiltered fresh olive oil that has a slightly cloudy appearance is called cloudy olive oil.
This form of olive oil used to be popular only among olive oil small
scale producers but is now becoming "trendy", in line with consumer's
demand for more ecological and less-processed "green" products.
The remaining paste (pomace) still contains a small quantity (about
5–10%) of oil that cannot be extracted by further pressing, but only
with chemical solvents. This is done in specialised chemical plants, not
in the oil mills. The resulting oil is not "virgin" but "pomace oil".
The term "first press", sometimes found on bottle labels, is today
meaningless, as there is no "second" press; it comes from ancient times
of stone presses, when virgin oil was the one produced by battering the
olives.
The label term "cold-extraction" on extra virgin olive oils indicates
that the olive grinding and stirring was done at a temperature of
maximum 25 °C (77 °F), as treatment in higher temperatures risks
decreasing the olive oils' quality (texture, taste and aroma).
Constituents
General chemical structure of olive oil (
triglyceride). R
1, R
2 and R
3 are
alkyl groups (approx. 20%) or alkenyl groups (approx. 80%).
Olive oil is composed mainly of the mixed triglyceride esters of
oleic acid and
palmitic acid and of other
fatty acids, along with traces of
squalene (up to 0.7%) and
sterols (about 0.2%
phytosterol and tocosterols). The composition varies by cultivar, region, altitude, time of harvest, and extraction process.
Phenolic composition
Olive oil contains phenolics such as
esters of
tyrosol and
hydroxytyrosol, including
oleocanthal and
oleuropein, having
acidic properties that give extra-virgin unprocessed olive oil its
bitter and pungent
taste. Olive oil is a source of at least 30 phenolic compounds.
Elenolic acid
is a component of olive oil and olive leaf extract. It can be
considered as a marker for maturation of olives. Oleuropein, together
with other closely related compounds such as 10-hydroxyoleuropein,
ligstroside and 10-hydroxyligstroside, are tyrosol esters of elenolic
acid.
Both hydroxytyrosol and its precursor oleuropein exist in the fruit
at levels on the order of 100 times that of shelf extra virgin olive
oil. Phenolics are considerably higher in fresh
cloudy olive oil than extra virgin that has been separated and aged.
Other phenolic constituents include
aldehydic secoiridoids,
flavonoids and
lignans (
acetoxypinoresinol,
pinoresinol). The latter two compounds are only present in extra virgin oil.
Health benefits
Hydroxytyrosol
(2-(3,4-Di-hydroxyphenyl)-ethanol or DHPE) is a phenolic component of
extra-virgin olive oil. An olive oil fraction containing DHPE was shown
to inhibit
platelet aggregation and
eicosanoid (
thromboxane B2) formation in vitro.
Oleocanthal from olive oil is a non-selective inhibitor of
cyclooxygenase (COX) similar to classical
NSAIDs like
ibuprofen.
It has been suggested that long-term consumption of small quantities of
this compound from olive oil may be responsible in part for the low
incidence of
heart disease associated with a
Mediterranean diet.
Nutrition
As they are the least processed forms of olive oil, extra virgin or
virgin olive oil have more monounsaturated fatty acids than other olive
oil. These types also contain more polyphenols, which may have benefits
for the heart.
One
tablespoon of olive oil (13.5 g) contains the following nutritional information according to the USDA:
- Calories : 119
- Fat: 13.50
- Carbohydrates: 0
- Fibers: 0
- Protein: 0
Popular uses and research
Skin
Olive oil has a long history of being used as a home remedy for
skincare. Egyptians used it alongside beeswax as a cleanser,
moisturizer, and antibacterial agent since pharaonic times.
In ancient Greece, the substance was used during massage, to prevent
sports injuries, relieve muscle fatigue, and eliminate lactic acid
buildup.
In 2000, Japan was the top importer of olive oil in Asia (13,000 tons
annually) because consumers there believe both the ingestion and topical
application of olive oil to be good for skin and health.
There has been relatively little scientific work done on the effect
of olive oil on acne and other skin conditions. However, one study noted
that the abundance of
squalene
in oils in general shows promise for sufferers of seborrheic
dermatitis, acne, psoriasis, and atopic dermatitis. Squalene is used as
an antioxidant, moisturizer, and as a convenient vehicle to carry other
substances in topical application.
Another researcher reported that a mixture of honey, beeswax, and olive
oil alleviates diaper dermatitis, psoriasis, and eczema by inhibiting
the growth of
Staphylococcus aureus and
Candida albicans.
Olive oil is popular for use in massaging infants and toddlers, but
scientific proof of its efficacy is mixed. One analysis of olive oil
versus mineral oil found that, when used for infant massage, olive oil
can be considered a safe alternative to sunflower, grapeseed and
fractionated coconut oils. This stands true particularly when it is
mixed with a lighter oil like sunflower, which "would have the further
effect of reducing the already low levels of free fatty acids present in
olive oil". The study also notes that there appears to be much
confusion surrounding mineral oil, and that further studies should be
done on refined mineral oil to back up claims about its superiority to
olive oil.
Another trial echoes this claim, stating that olive oil lowers the risk
of dermatitis for infants in all gestational stages when compared with
emollient cream.
However, yet another study found that topical treatment with olive oil
for newborns "significantly damages the skin barrier" when compared to
sunflower oil, and that it may make existing atopic dermatitis worse.
The researchers conclude that they do not recommend the use of olive oil
for the treatment of dry skin and infant massage.
Clinical trials have found that olive oil does not act to prevent or reduce stretch marks.
The fatty substance was found to reduce inflammation via
oleuropein, which is touted for its antioxidant, anti-atherosclerotic, and anti-inflammatory characteristics.
Potential health effects attributed to fat composition
Preliminary clinical studies provide evidence that consumption of
olive oil may lower risk of heart disease risk factors such as lower
blood
cholesterol levels and reduced
LDL cholesterol
oxidation, and that it may also possibly influence inflammatory,
thrombotic,
hypertensive and
vasodilatory mechanisms. Although epidemiological studies indicate that a higher proportion of
monounsaturated fats in the diet may be linked with a reduction in the risk of
coronary heart disease, a cause and effect relationship has not yet been established with sufficient scientific evidence.
In the United States, producers of olive oil may place the following restricted health claim on product labels:
- Limited and not conclusive scientific evidence suggests that eating about 2 tbsp.
(23 g) of olive oil daily may reduce the risk of coronary heart disease
due to the monounsaturated fat in olive oil. To achieve this possible
benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day.
This decision was announced November 1, 2004, by the Food and Drug
Administration after application was made to the FDA by producers.
Similar labels are permitted for foods rich in
omega-3 fatty acids such as
walnuts and
hemp seed.
Other possible effects of olive oil may be a property to balance omega-6 fats and omega-3 fats
[citation needed] and to affect
blood sugar levels and blood pressure, but these effects were dismissed in reviews by the Scientific Committee of the
European Food Safety Authority.
Olive oil contains the monounsaturated fatty acid
oleic acid,
vitamin E and
oleuropein, a chemical that may affect the oxidation of LDL particles.
Preliminary research indicates that olive oil could possibly be a chemopreventive agent for
peptic ulcer or
gastric cancer, but confirmation requires further
in vivo study.
Pilot studies showed that olive oil may reduce oxidative damage to DNA and RNA, revealing a possible anti-
carcinogenic factor. Consumption of olive oil may prevent the onset of
Alzheimer's disease, possibly through a mechanism related to
oleocanthal inhibiting fibrillization of
tau protein.
Uses
Culinary use
Olive oil is the main
cooking oil in countries surrounding the
Mediterranean Sea.
Extra virgin olive oil is mostly used as a
salad dressing
and as an ingredient in salad dressings. It is also used with foods to
be eaten cold. If uncompromised by heat, the flavor is stronger. It also
can be used for
sautéing.
The higher the temperature to which the olive oil is heated, the
higher the risk of compromising its taste. When extra virgin olive oil
is heated above 210–216 °C (410–421 °F), depending on its free fatty
acid content, the unrefined particles within the oil are burned. This
leads to deteriorated taste. Also, the pronounced taste of extra virgin
olive oil is not a taste most people like to associate with their deep
fried foods. Refined olive oils are perfectly suited for
deep frying foods and should be replaced after several uses.
[citation needed]
Choosing a cold-pressed olive oil can be similar to selecting a
wine.
The flavor of these oils varies considerably and a particular oil may
be more suited for a particular dish. Also, people who like lots of
tannins in their
red wines might prefer more bitter olive oils.
An important issue often not realized in countries that do not
produce olive oil is that the freshness makes a big difference. A very
fresh oil, as available in an oil producing region, tastes noticeably
different from the older oils available elsewhere. In time, oils
deteriorate and become stale. One-year old oil may be still pleasant to
the taste, but it is surely less fragrant than fresh oil. After the
first year, olive oil should be used for cooking, not for foods to be
eaten cold, like salads.
The taste of the olive oil is influenced by the varietals used to
produce the oil from and by the moment when the olives are harvested and
ground (less ripe olives give more bitter and spicy flavors - riper
olives give a sweeter sensation in the oil).
For certain culinary uses, olive oil may be substituted with
safflower or
sunflower oils,
canola oil,
peanut oil,
sesame oil, or
coconut oil.
Olive oil has various non-culinary uses as well. For example, it is also a natural and safe
lubricant,
and can be used to lubricate machinery that is used within the kitchen
(grinders, blenders, cookware, etc.) It can also be used for
illumination (oil lamps) or as the base for soaps and detergents.
Some cosmetics also use olive oil as their base.
Religious use
 |
| Olive tree in Portugal |
Olive oil also has religious symbolism for healing and strength and
to consecration— setting a person or place apart for special work. This
may be related to its ancient use as a medicinal agent and for cleansing
athletes by slathering them in oil then scraping them.
Judaism
In
Jewish observance, olive oil is the only fuel allowed to be used in the seven-branched
Menorah in the
Mishkan service during
the Exodus of the tribes of
Israel from
Egypt, and later in the permanent
Temple in Jerusalem.
It was obtained by using only the first drop from a squeezed olive and
was consecrated for use only in the Temple by the priests and stored in
special containers. A menorah similar to the Menorah used in the Mishkan
is now used during the
holiday of
Hanukkah
that celebrates the miracle of the last of such containers being found
during the re-dedication of the Temple (163 BC), when its contents
lasted for far longer than they were expected to, allowing more time for
more oil to be made. Although candles can be used to light the
hanukkiah,
oil containers are preferred, to imitate the original Menorah. Another
use of oil in Jewish religion is for anointing the kings of the Kingdom
of Israel, originating from King David.
Tzidkiyahu was the last anointed King of Israel.
Christianity
The Catholic and Orthodox Churches use olive oil for the
Oil of Catechumens (used to bless and strengthen those preparing for Baptism) and Oil of the Sick (used to confer the Sacrament of
Anointing of the Sick or
Unction). Olive oil mixed with a perfuming agent such as
balsam is
consecrated by
bishops as Sacred
Chrism, which is used to confer the sacrament of
Confirmation (as a symbol of the strengthening of the Holy Spirit), in the rites of
Baptism and the
ordination of
priests and bishops, in the consecration of
altars and
churches, and, traditionally, in the anointing of monarchs at their
coronation.
The Church of Jesus Christ of Latter-day Saints (
Mormons) and a number of other religions use olive oil when they need to consecrate an oil for anointings.
Eastern Orthodox Christians
still use oil lamps in their churches, home prayer corners and in the
cemeteries. A vigil lamp consists of a votive glass containing a
half-inch of water and filled the rest with olive oil. The glass has a
metal holder that hangs from a bracket on the wall or sits on a table. A
cork float with a lit wick floats on the oil. To douse the flame, the
float is carefully pressed down into the oil. Makeshift oil lamps can
easily be made by soaking a ball of cotton in olive oil and forming it
into a peak. The peak is lit and then burns until all the oil is
consumed, whereupon the rest of the cotton burns out. Olive oil is a
usual offering to churches and cemeteries.
In the Orthodox Church, olive oil is a product not consumed during
lent or
penance while Orthodox
monks use it sparingly in their diet. Exceptions are in feast days and Sundays.
Islam
In
Islam,
olive oil is mentioned in the
Quranic verse:
"Allah is the Light of the heavens and the earth. The parable of His
Light is as (if there were) a niche and within it a lamp: the lamp is in
a glass, the glass as it were a brilliant star, lit from a blessed
tree, an
olive, neither of the east (i.e. neither it gets
sun-rays only in the morning) nor of the west (i.e. nor it gets sun-rays
only in the afternoon, but it is exposed to the sun all day long),
whose oil would almost glow forth (of itself), though no fire touched
it. Light upon Light! Allah guides to His Light whom He wills. And Allah
sets forth parables for mankind, and Allah is All-Knower of
everything." ( سورة النور , An-Noor, Chapter #24, Verse #35)
Other
- Olive oil may be used in soap making, as lamp oil, a lubricant, or as a substitute for machine oil.
- Olive oil has also been used as both solvent and ligand in the synthesis of cadmium selenide quantum dots.
- In one study, monounsaturated fats such as from olive oil benefited mood, decreased anger, and increased physical activity.
