Olive oil

Author: Giancarlo Dessì

Olive oil

Olive oil 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 Greece, which has the highest consumption per person.


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 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 to modern Turkey in the 4th millennium; or somewhere in the Mesopotamian Fertile Crescent in the 3rd millennium.

Ancient Greek olive oil production workshop in Klazomenai, Ionia (modern Turkey)
A widespread view exists that the first cultivation took place on the island of Crete. Archeological evidence suggest 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. An alternative view retains that olives were turned into oil by 4500 BC by Canaanites in present-day Israel.[5] Until 1500 BC, 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.
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.[citation needed]
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 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 in 1000 BC, the fertile crescent, and 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.

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 naked appearance of athletes, 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.


Among the many different olive varieties or List of olive cultivars there are: in Greece Koroneiki, Lianolia, Chondrolia (a.k.a. Throumbolia), Tsounati, Patrinia and more.
In Spain, the most important varieties are the Picual, Arbequina, Hojiblanca, and Manzanillo de Jaén; In Italy, Frantoio, Leccino Pendolino, and Moraiolo; in France, Picholine; in California, Mission; in Portugal, Galega, Verdeal and Cobrançosa; in Croatia, Oblica and Leccino. The oil from the varieties varies in flavour and stability (shelf life).

Production and consumption

Spain produces 43.8% of world production of olive oil. 75% of Spain's production comes from the region of Andalucía, particularly within Jaén province, although other regions, including Catalonia 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. Greece accounts for 12.1% of world Production and Syria for 6.1%, as third and fourth largest producers in the World. Portugal accounts 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 m3) of olive oil in 1998, of which 34,600,000 US gallons (131,000 m3) 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 USA grocery market shelves alongside the Mediterranean olive oils.


Main article: Olive oil regulation and adulteration

International Olive Council building
The International Olive Council (IOC) is an intergovernmental organization based in Madrid, Spain, with 16 member states plus the European Union. It promotes olive oil around the world by tracking production, defining quality standards, and monitoring authenticity. More than 98 per cent of the world's olives are grown in IOC member nations. The United States is not a member of the IOC, and the U.S. Department of Agriculture does not legally recognize its classifications (such as extra-virgin olive oil). The USDA uses a different system, which it defined in 1948 before the IOC existed. On October 25, 2010, the United States adopted new olive oil standards, a revision of those that had been in place since 1948, which affect importers and domestic growers and producers by ensuring conformity with the benchmarks commonly accepted in the U.S. and abroad.
Olive oil is classified by how it was produced, by its chemistry, and by panels that perform olive oil taste testing. 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.
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." These products are a mixture of olive oil from more than one nation and it is not clear what percentage of the olive oil is really of Italian origin. This practice makes it difficult for high quality, lower cost producers outside of Italy to enter the U.S. market, and for genuine Italian producers to compete.

Commercial grades

All production begins by transforming the olive fruit into olive paste. This paste is then malaxed (slowly churned or mixed) 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 grades of oil extracted from the olive fruit can be classified as:
Virgin means the oil was produced by the use of physical means and no chemical treatment. The term virgin oil referring to production is different from Virgin Oil on a retail label (see next section).
Refined means that the oil has been chemically treated to neutralize strong tastes (characterized as defects) and neutralize the acid content (free fatty acids). Refined oil is commonly regarded as lower quality than virgin oil; oils with the retail labels extra-virgin olive oil and virgin olive oil cannot contain any refined oil.
Olive pomace oil means oil extracted from the pomace using solvents, mostly hexane, and by heat.
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.
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.

Retail grades in IOC member nations

Italian label for "extra vergine" oil
In countries that adhere to the standards of the International Olive Council (IOC)[28] the labels in stores show an oil's grade.
Extra-virgin olive oil Comes from virgin oil production only, contains no more than 0.8% acidity, and is judged to have a superior taste. 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: 45%, Spain 30%). It is used on salads, added at the table to soups and stews and for dipping.
Virgin olive oil Comes from virgin oil production only, has an acidity less than 1.5%, and is judged to have a good taste.
Pure olive oil. Oils labeled as Pure olive oil or Olive oil are usually a blend of refined and virgin production oil.
Olive oil is a blend of virgin and refined production oil, of no more than 2% acidity. It commonly lacks a strong flavor.
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.
Lampante oil is olive oil not suitable as food; lampante comes from olive oil's long-standing use in oil-burning lamps. Lampante oil is mostly used in the industrial market.
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.



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).
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).

Source: http://en.wikipedia.org/wiki/Olive_oil ...


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