See A. Dolamore, The Essential Olive Oil Companion (1989).
Olive oil is a fruit oil obtained from the olive (Olea europaea; family Oleaceae along with lilacs, jasmine and ash trees), a traditional tree crop of the Mediterranean Basin. The wild olive tree originated in Asia Minor, today the country of Turkey. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps.
World production in 2002 was 2.6 million metric tons, of which Spain contributed 40% to 45%. In 2006 Turkey accounted for about 5% of world production, similar to the Spanish province of Jaen alone, well known for the biggest olive groves in the world..
Greece devotes 60% of its cultivated land to olive growing. It is the world's top producer of black olives and has more varieties of olives than any other country. Greece holds third place in world olive production with more than 132 million trees, which produce approximately 350,000 tons of olive oil annually, of which 82% is extra-virgin (see below for an explanation of terms). About half of the annual Greek olive oil production is exported, but only some 5% of this reflects the origin of the bottled product. Greece exports mainly to European Union (EU) countries, principally Italy, which receives about three-quarters of total exports. Olives are grown for oil in mainland Greece, with Peloponnese being the source of 65% of Greek production, as well as in Crete, the Aegean Islands and Ionian Islands.
Among the many different olive varieties or cultivars in Italy are Frantoio, Leccino Pendolino, and Moraiolo. In Spain the most important varieties are the Picual, Alberquina, Hojiblanca, and Manzanillo de Jaén. In Greece : Koroneiki. In France : Picholine. In California : Mission. In Portugal : Galega. The oil from the varieties varies in flavour and stability (shelf life).
In North America, Italian and Spanish olive oils are the best-known, and top-quality extra-virgin oils from Italy, Spain and Greece are sold at high prices, often in "prestige" packaging. A large part of US olive oil imports come from the EU, especially Spain. The US imported 28.95 million gallons of olive oil in 1994, a 215% increase from 1984. The US is Italy's biggest customer, importing 22% of total Italian production of 131.6 million gallons in 1994.
The IOOC officially governs 95% of international production and holds great influence over the rest. IOOC terminology is precise, but it can lead to confusion between the words that describe production and the words used on retail labels. Olive oil is classified by how it was produced, by its chemistry, and by its flavor. All production begins by transforming the olive fruit into olive paste. This paste is then malaxed to allow the microscopic oil droplets to concentrate. The oil is extracted by means of pressure (traditional method) or centrifugation (modern method). After extraction the remnant solid substance, called pomace, still contains a small quantity of oil.
The EU regulates the use of different protected designation of origin labels for olive oils.
An article by Tom Mueller in the August 13, 2007 Issue of the The New Yorker alleges that regulation, particularly in Italy, is extremely lax and corrupt. Mueller states that major Italian shippers routinely adulterate olive oil and that only about 40% of olive oil sold as "extra virgin" actually meets the specification. In some cases, colza oil 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.
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.
Adulterated oil is usually no more serious than passing off inferior, but safe, product as superior olive oil, but there are no guarantees. Almost 700 people died, it is believed, as a consequence of consuming rapeseed (canola) oil adulterated with aniline intended for use as an industrial lubricant, but sold in 1981 as olive oil in Spain
Quantitative analysis can determine the oil's acidity, defined as the percent, measured by weight, of free oleic acid it contains. This is a measure of the oil's chemical degradation; as the oil degrades, more fatty acids are freed from the glycerides, increasing the level of free acidity and thereby increasing rancidity. Another measure of the oil's chemical degradation is the organic peroxide level, which measures the degree to which the oil is oxidized, another cause of rancidity.
In order to classify it by taste, olive oil is subjectively judged by a panel of professional tasters in a blind taste test. This is also called its organoleptic quality.
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The most traditional way of making olive oil is by grinding olives. Green olives produce bitter oil, and overripe olives produce rancid oil, so care is taken to make sure the olives are perfectly ripened. First the olives are ground into paste using large millstones. The olive paste generally stays under the stones for 30–40 minutes. The oil collected during this part of the process is called virgin oil. After grinding, the olive paste is spread on fibre disks, which are stacked on top of each other, then placed into the press. Pressure is then applied onto the disk to further separate the oil from the paste. This second step produces a lower grade of oil.
Olive oil contains a group of related natural products with potent antioxidant properties which give extra-virgin unprocessed olive oil its bitter and pungent taste and which are esters of tyrosol and hydroxytyrosol, including oleocanthal and oleuropein.
Evidence from epidemiological studies suggests that a higher proportion of monounsaturated fats in the diet is linked with a reduction in the risk of coronary heart disease. This is significant because olive oil is considerably rich in monounsaturated fats, most notably oleic acid.
In the United States, producers of olive oil may place the following health claim on product labels:
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.
There is a large body of clinical data to show that consumption of olive oil can provide heart health benefits such as favourable effects on cholesterol regulation and LDL cholesterol oxidation, and that it exerts antiinflamatory, antithrombotic, antihypertensive as well as vasodilatory effects both in animals and in humans.
But some clinical evidence suggests that it is olive oil's phenolic content, rather than its fatty acid profile, that is responsible for at least some of its cardioprotective benefits. For example, a clinical trial published in 2005 compared the effects of different types of olive oil on arterial elasticity. Test subjects were given a serving of 60 grams of white bread and 40 milliliters of olive oil each morning for two consecutive days. The study was conducted in two stages. During the first stage, the subjects received polyphenol-rich oil (extra virgin oil contains the highest amount of polyphenol antioxidants). During the second phase, they received oil with only one fifth the phenolic content. The elasticity of the arterial walls of each subject was measured using a pressure sleeve and a Doppler laser. It was discovered that after the subjects had consumed olive oil high in polyphenol antioxidants, they exhibited increased arterial elasticity, while after the consumption of olive oil containing fewer polyphenols, they displayed no significant change in arterial elasticity. It is theorized that, in the long term, increased elasticity of arterial walls reduces vascular stress and consequentially the risk of two common causes of death—heart attacks and stroke. This could, at least in part, explain the lower incidence of both diseases in regions where olive oil and olives are consumed on a daily basis.
Another health benefit of olive oil seems to be its property to displace omega-6 fats, while not having any impact on omega-3 fats. This way, olive oil helps to build a more healthy balance between omega-6 fats and omega-3 fats.
In addition to the internal health benefits of olive oil, topical application is quite popular with fans of natural health remedies. Extra Virgin Olive Oil is the preferred grade for moisturizing the skin, especially when used in the Oil Cleansing Method (OCM). OCM is a method of cleansing and moisturizing the face with a mixture of extra virgin olive oil, castor oil (or another suitable carrier oil) and a select blend of essential oils. Olive oil is used by some to reduce ear wax buildup.
Jeanne Calment, who holds the record for the longest confirmed lifespan, reportedly attributed her longevity and relatively youthful appearance to olive oil, which she said she poured on all her food and rubbed into her skin.
However, some of these benefits are disputed. Several scientific studies doubt some of the previously stated positive effects and state several negative effects of olive oil such as impairment of the dilation of the arteries.
One of the best remedies for body rash is to apply the olive oil on the affected area. Olive oil penetrate into the skin and cures the rash.
Extra-virgin olive oil is mostly used for salad dressings and foods to be eaten cold. Used cold, its strong flavor is able to stick out while not being compromised by heat. It is also used for frying ingredients. Refined olive oils are perfectly suited for deep frying foods and should be replaced after six times of use.
The higher the temperature to which the olive oil is heated, the more one should prefer the use of refined olive oils. When extra-virgin olive oil is heated above 350°F (180°C), the unrefined particles within the oil get burned. This leads to deteriorated taste and even toxicity. Also, the pronounced taste of extra-virgin olive oil is not a taste most people like to associate with their deep fried foods.
Choosing a cold-pressed olive oil can be similar to selecting a wine. The flavor of these oils vary 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 which is 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.
Olive oil is unlikely to cause allergic reactions, and as such is used in preparations for lipophilic drug ingredients. It does have demulcent properties, and mild laxative properties, acting as a stool softener. It is also used at room temperature as an ear wax softener. Olive oil is also a potent blocker of intestinal contractions, and can be used to treat excessive Borborygmus.
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.
Homer called it "liquid gold." In ancient Greece, athletes ritually rubbed it all over their body. Olive oil has been more than mere food to the peoples of the Mediterranean: it has been medicinal, magical, an endless source of fascination and wonder and the fountain of great wealth and power.
Besides food, olive oil has been used for religious rituals, medicines, as a fuel in oil lamps, soap-making, and skin care application. 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.
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 to modern Turkey in the 4th millennium ; or somewhere in the Mesopotamian Fertile Crescent in the 3rd millennium.
A widespread view exists that the first cultivation took place on the island of Crete. 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. An alternative view retains that olives were turned into oil by 4500 BC by Canaanites in present-day Israel.
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.
Many ancient presses still exist in the Eastern Mediterranean region, and some dating to the Roman period are still in use today.
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.
Until 1500 BC, the eastern coastal areas of the Mediterranean were most heavily cultivated. 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. 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.. Olive tree growing reached Iberia and Etruscan cities well before the 8th century BC through trade with the Phoenicians and Carthage, then 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. 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 the Kingdom of Israel c. 1000 BC. 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.
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 first century AD, "the best in the Mediterranean", he maintained, a claim probably disputed by many ancient olive growers. Thus olive oil was very common in Hellene and Latin cuisine. According to legend, 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 were the Hellenes who used oil to rub themselves while exercising in the gymnasia. The practice served to eroticise and highlight the beauty of the male body. From its beginnings early in the seventh century BC, the decorative use of olive oil quickly spread to all of Hellenic city states, together with naked appearance of athletes, and lasted close to a thousand years despite its great expense.
Olive oil also has religious symbolism for healing and strength and to consecration — God's 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. 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). Olive oil mixed with a perfuming agent like 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 and home prayer corners. 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 lit a wick floats on the oil. To douse the flame, the float is carefully pressed down into the oil.
In Islam, olive oil is mentioned in the Quranic verse: "God is the light of heavens and earth. An example of His light is like a lantern inside which there is a tourch, the tourch is in a glass bulb, the glass bulb is like a bright planet lit by a blessed olive tree, neither Eastern nor Western, its oil almost glows, even without fire touching it, light upon light." The Qur’an also mentions olives as a sacred plant: "By the fig and the olive, and the Mount of Sinai, and this secure city." Olive oil is also reported to have been recommended by the Muslim Prophet Muhammad in the following terms: "Consume olive oil and anoint it upon your bodies since it is of the blessed tree." He also stated that it cures 70 diseases.