Olive oil is an oil obtained from the olive (Olea europaea; family Oleaceae), a traditional tree crop of the Mediterranean Basin. 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.
However, the archaeological data from Asia Minor shows that Olive trees started from Iran, Syria and Palestine and gradually were cultivated to the rest of the Mediterranean basin 6,000 years ago. It is among the oldest known cultivated trees in the world - being grown before the written language was invented. It was being grown on Crete in large number by 3,000 BC and may have been the source of the wealth of the Minoan kingdom. Crete Olive is still considered the best in the world. The Phoenicians spread the olive to the Mediterranean shores of Africa and Southern Europe. Olives have been found in Egyptian tombs from 2,000 years BC. The olive culture was spread to the early Greeks then Romans. As the Romans extended their domain they brought the olive with them.
The Greek Poet Homer, the author of Liad and Odyssey called it "liquid gold." In ancient Greece, athletes ritually rubbed it all over their bodies. 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. Indeed the importance of the olive industry in ancient economies cannot be overstated. The tree is extremely hardy and its useful lifespan can be measured in centuries. Its wide and deep root system ensures its survival without additional watering, even in the water-sparse Mediterranean. It thrives close to the sea, where other plants cannot tolerate the increased salt content of underground water. Other than pruning in late spring, it needs minimal cultivation and its fruit matures in the late autumn in the Northern Mediterranean) or through the winter (further south), when other staple food harvests are over and there is no other agricultural work to be done. Olive collecting and processing is relatively straightforward, and needs minimal, mechanical technology. Olive oil, being almost pure fat, is dense in calories yet healthy, without adverse health effects. Unlike cereals which can be destroyed by humidity and pests in storage, olive oil can be very easily stored and will not go rancid for at least a year (unless needlessly exposed to light or extremely hot weather), by which time a fresh harvest will be available. The combination of these factors helped ensure that the olive industry has become the region's most dependable food and cash crop since prehistoric times.
The olive tree was a particularly important symbol for the ancient Greeks. It was connected to their diet and their religion, and was used as a decorative motif on vases, in gold jewellery and elsewhere. It was considered a symbol of peace, wisdom and victory. That is why the winners of the Olympic Games were crowned with a wreath of wild olive (the cotinus).
Olives in antiquity were usually gathered by beating the tree with rods, although ancient authors condemned this practice. Pliny repeatedly recommends: “Do not shake and beat your trees. Gathering by hand each year ensures a good harvest.”
The olive-harvesting knowledge of the ancients, incredibly advanced for its time, was often aided by astronomy, used to predict poor harvests. Thales of Miletus, for example, used his astronomical observations to predict an excellent harvest for 596 BC. He immediately established many new oil-presses on Chios and Melos, making the islands’ inhabitants rich in a year. Democritus also studied the relationship between good harvests and the positions of the stars.
Olive oil had many uses in ancient Greece, differing according to social status. Poor people, for instance, did not consume olive oil but ate many cereals. The rich, on the other hand, were able to use olive oil in cooking, for cleaning their bodies and for lighting.
Olive oil was also a valuable medicine in the hands of ancient Greek doctors. Hippocrates mentions 60 different conditions which could be treated with it, such as skin conditions, wounds and burns, gynaecological ailments, ear infections and many others.
Greek Athlete removing the olive oil from his body with a stlengis (strigil)
When medicine was not enough to save the patient, olive oil was used in laying out the dead. Women washed the body and anointed it with olive oil or scented oils. Oil, wine, honey and other products were offered to the dead at the graveside.
Another popular use of olive oil in ancient Greece was for oiling athletes’ bodies before exercise in the gymnasium and at games.
Olive oil was also a valuable winner’s prize. The city of Athens needed about 70,000 kilos of oil to reward the winners of the Panathenian Games, held every four years.
The winner’s prize varied according to the event. The best runner received about 70 amphoras of 35-40 kilos, i.e. 2,500 kilos of olive oil, while the chariot-race winner got double, i.e. about 5,000 kilos. These prizes were worth a lot of money if you consider that a day’s wages for an Athenian craftsman was 1 Attic drachma, the equivalent of about 3 kilos of olive oil. And that was just the price of common oil, whereas the winner’s oil was much better quality and more expensive. Of course no-one would buy this oil to eat; instead it was used for anointing the bodies of rich young athletes.
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.
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, 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.
In the Islamic world, around 1,400 years ago the Prophet Muhammad, advised his followers to apply olive oil to their bodies, and himself used oil on his head. The use of oil is found in many religions and cultures. It has been used during special ceremonies as well as a general health measure. During baptism in the Christian church, holy oil, which is often olive oil, may be used for anointment. At the Christmas mass, olive oil blessed by the bishop, "chrism", is used in the ceremony. Like the grape, the Christian missionaries brought the olive tree with them to California for food but also for ceremonial use. Olive oil was used to anoint the early kings of the Greeks and Jews. The Greeks anointed winning athletes. Olive oil has also been used to anoint the dead in many cultures.
It is thought that the olive trees on the Mount of Olives in Jerusalem are reputed to be over 2000 years old, still relative newcomers considering the long domestication of the olive. We don't know the exact variety of the trees on the Mount. Man has manipulated the olive tree for so many thousands of years that it is unclear what varieties came from which other varieties. Varieties in one country have been found to be identical to differently named varieties in another. Some research is now being done using gene mapping techniques to figure out the olive family tree. Shrub-like "feral" olives still exist in the Middle East and represent the original stock from which all other olives are descended.
In the past several hundred years the olive has spread to North and South America, Japan, New Zealand and Australia and China.
An old wives tails
Athens is named for the Goddess Athena who brought the olive to the Greeks as a gift. Zeus had promised to give Attica to the god or goddess who made the most useful invention. Athena's gift of the olive, useful for light, heat, food, medicine and perfume was picked as a more peaceful invention than Poseidon's horse - touted as a rapid and powerful instrument of war. Athena planted the original olive tree on a rocky hill that we know today as the Acropolis. The olive tree that grows there today is said to have come from the roots of the original tree.
Now days Among the many different olive varieties or cultivars there are: in Greece Koroneiki, Lianolia, Chondrolia (aka Throumbolia), Tsounati and more. In Italy, Frantoio, Leccino Pendolino, and Moraiolo are the most famous varieties of cultivars. In Spain, the most important varieties are the Picual, Arbequina, Hojiblanca, and Manzanilla de Jaén; in France, Picholine; in California, Mission; in Portugal, Galega; in Croatia, Oblica and Leccino. The oil from the varieties varies in flavour and stability (shelf life).
Australia now produces much olive oil. Many Australian producers only make premium oils, whilst 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, 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.The Republic of South Africa also produces extra virgin olive oil, with production increasing to meet demand.
Olive Oil Commercial Grades
The grades of Olive oil extracted from the olive fruit can be classified as:
- Virgin Olive Oil 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 Olive Oil 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 of Olive Oil 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 Olive Oil 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 IOC 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 2%, 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 1.5% 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, rendering 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. Over 50% of the oil produced in the Mediterranean area is of such poor quality that it must be refined to produce an edible product. 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. An obsolete equivalent is "pure olive oil".
The 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 are the healthiest, since they contain the highest levels of polyphenols, antioxidants that have been linked with better health.
"Made from refined olive oils" means that the taste and acidity were chemically controlled.
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 US Food and Drug Administration permitted a claim on olive oil labels stating: "Limited and not conclusive scientific evidence suggests that eating about two tablespoons (23g) of olive oil daily may reduce the risk of coronary heart disease.
The main producing and consuming countries are:
Country Production in tons (2009) Production % (2009) Consumption (2005)
||Production in tons (2009)
||Production % (2009)
||Annual per capita consumption (kg)
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 amongst olive oil small scale producers but is now becoming "trendy", in line with consumer's demand for more ecological and less-processed "green" products.
Nutrition and health effects
Percentages are relative to US recommendations for adults.
Olive oil contains a wide variety of valuable antioxidants that are not found in other oils. Hydroxytyrosol is thought to be the main antioxidant compound in olives, and believed to play a significant role in the many health benefits attributed to olive oil. Epidemiological studies suggest that olive oil has a protective effect against certain malignant tumours in the breast, prostate, endometrium and digestive tract. Research has revealed that the “type” rather than the “quantity” of fat seems to have more implications for cancer incidence.
Evidence from epidemiological studies also 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:
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 Almonds and hemp seed.
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.
Additionally, Olive oil protects against heart disease as it controls the "bad" levels of LDL cholesterol and raises levels of the "good" cholesterol, HDL.
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.
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.
Another health benefit of olive oil seems to be its property to displace omega-6 fatty acids, while not having any impact on omega-3 fatty acids. This way, olive oil helps to build a more healthy balance between omega-6 fats and omega-3 fats.
Unlike saturated fats, olive oil lowers total cholesterol and LDL levels in the blood. It is also known to lower blood sugar levels and blood pressure.
Olive oil contains the monounsaturated fatty acid oleic acid, antioxidants such as vitamin E and carotenoids, and oleuropein, a chemical that may help prevent 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. Olive oil was also found to reduce oxidative damage to DNA and RNA, which may be a factor in preventing cancer.
Unsaturated oils, such as olive oil, have a short shelf life and are prone to becoming rancid from oxidation, which will produce toxic byproducts and a bitter taste. Protection of unsaturated oils from heat and light will delay spoilage.
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 more one should prefer the use of refined olive oils. When extra virgin olive oil is heated above 350 °F (177 °C), 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.
Choosing a cold-pressed olive oil can be similar to selecting a wine. The flavour 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 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 not only by the soil on which the olive trees grow, but also by the moment when the olives have been harvested and ground.
Olive oil has more uses than as food; it also works as a natural and safe lubricant, such as lubricating the machinery that is used within the kitchen (grinders, blenders, cookware, etc.)