2007 Schools Wikipedia Selection. Related subjects: Food and agriculture
Nutritional value per 100 g
|Energy 890 kcal 3700 kJ|
|100 g olive oil is 109 ml
Percentages are relative to US
recommendations for adults.
Olive oil is a vegetable oil obtained from the olive (Olea europaea L.), a traditional tree crop of the Mediterranean Basin. It is used in cooking, cosmetics, soaps and as a fuel for traditional oil lamps. Olive oil is regarded as a healthful dietary oil because of its high content of monounsaturated fat (mainly oleic acid) and polyphenols.
Grades and classification
The International Council (IOOC) sets standards of quality used by the major olive oil producing countries. It officially governs 95 percent 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 several oils 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; the retail labels extra-virgin olive oil and virgin olive oil cannot contain any refined oil.
- Pomace olive oil means oil extracted from the pomace using chemical solvents — mostly hexane — and by heat.
Quantitative analytical methods determine the oil's acidity, defined as the percent, measured by weight, of free oleic acid in it. This is a measure of the oil's chemical degradation — as the oil degrades, more fatty acids get free from the glycerides, increasing the level of free acidity. Another measure of the oil's chemical degradation is the peroxide level, which measures the degree to which the oil is oxidized ( rancid).
In order to classify olive oil by taste, it is subjectively judged by a panel of professional tasters in a blind taste test. This is also called its organoleptic quality.
Since IOOC standards are complex, the labels in stores (except in the US -- see below) clearly show an oil's grade:
- Extra-virgin olive oil comes from the first pressing of the olives, contains no more than 0.8% acidity, and is judged to have a superior taste. There can be no refined oil in extra-virgin olive oil.
- Virgin olive oil has an acidity less than 2%, and judged to have a good taste. There can be no refined oil in virgin olive oil.
- Olive oil is a blend of virgin oil and refined virgin oil, containing at most 1% acidity. It commonly lacks a strong flavor.
- Olive-pomace oil is a blend of refined pomace olive oil and possibly some virgin oil. It is fit for consumption, but it may not be called olive oil. Olive-pomace oil is rarely found in a grocery store; it is often used for certain kinds of cooking in restaurants.
- Lampante oil is olive oil not used for consumption; lampante comes from olive oil's ancient use as fuel in oil-burning lamps. Lampante oil is mostly used in the industrial market.
Olive oil vendors choose the wording on their labels very carefully.
- "Imported from Italy" produces an impression that the olives were grown in Italy, although in fact it only means that the oil was bottled there. A corner of the same label may note that the oil was packed in Italy with olives grown in Spain, Italy, Greece, Turkey, and Tunisia.
- "100% Pure Olive Oil" is often the lowest quality available in a retail store: better grades would have "virgin" on the label.
- "Made from refined olive oils" suggests that the essence was captured, but in fact means that the taste and acidity were chemically produced.
- "Light olive oil" suggests a low fat content, whereas in fact it refers to a lighter colour. All olive oil—which is, after all, fat—has 120 Calories per tablespoon (33 kJ/ ml).
- "From hand-picked olives" may indicate that the oil is of better quality, since producers harvesting olives by mechanical methods are inclined to leave olives to over-ripen, in order to maximise yield.
- "First cold press" means that the oil in bottles with this label is the first oil that came from the first press of the olives. The word "cold" is important because if heat is used, the olive oil's chemistry is changed.
- "D.O.P." when applied to Italian olive oil, denotes that the oil is made from olives that are typical of the region from which the oil derives, therefore may have a more characteristic taste than blended oils.
Retail grades in the US
Most of the governments in the world are members of the International Olive Oil Council, which requires member governments to promulgate laws making olive oil labels conform to the IOOC standards.
The United States, however, is not a member of the IOOC (it is the only significant oil-producing or -consuming country that is not), and therefore the retail grades listed above have no legal meaning in the US. The US Department of Agriculture (USDA), which controls this aspect of labeling, currently lists four grades of olive oil: Fancy, Choice, Standard, Substandard. These were established in 1948. The grades are based on acidity, absence of defects, odour and flavor. While the USDA is considering adopting labeling rules that parallel the international standards, until they do so terms like "extra virgin" may be applied to any grade of oil. As a consequence, the US is a dumping ground for old and mislabeled olive oil.
Therefore, US consumers should be wary of labels, especially ones that say "extra virgin." It is best to purchase olive oil for cooking from the lowest cost source (the supermarket, for example), but then to buy extra virgin oils for finishing, dipping, and dressings from a trusted specialty retailer.
World olive oil consumption
Greece has by far the heaviest per capita consumption of olive oil worldwide, over 26 liters per year; Spain and Italy, around 14 l; Tunisia, Portugal, and Syria, 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.
Price in an important factor on olive oil consumption in the world commodity market. In 1997, global production rose by 47%, which replenished low stocks, lowered prices, and increased consumption by 27%. Overall, world consumption trends are up by 2.5%. Production trends are also up due to expanded plantings of olives in Europe, Latin America, USA, and Australia.
The International Olive Oil Council is an inter-governmental organization based in Madrid, Spain that promotes olive oil around the world by tracking production, defining quality standards, and monitoring authenticity. More than 85% of the world's olives grow in the 23 nations that are members of the Council.
Over 750 million olive trees are cultivated world wide, the greatest number of which (c. 95%) being planted in the regions of the Mediterranean. About three quarters of the global olive oil production come from the European Union, while around 97% of European production comes from Spain, Italy and Greece.
Among global producers, Spain leads with more than 40% of world production, followed by Italy and Greece. Much of the Spanish crop is exported to Italy, where it is both consumed and repackaged for sale abroad as Italian olive oil. Although boutique groceries sell high-quality Spanish olive oil at a premium, Italian olive oil has the popular reputation for quality. Further still, many profess to the superior qualities of Greek olive oil.
Greece devotes 60% of its cultivated land to olive growing, is the world's top producer of black olives, and boasts 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 75% is extra virgin (which makes them the top producer of extra virgin olive oil) as compared with Italy (40-45%) or Spain (25-30%). About half of the annual Greek olive oil production is exported, while only some 5% of this quantity reflects the origin of the bottled product. Greek exports primarily target countries of the European Union, the main recipient being Italy, which receives about three quarters of total exports. Production is concentrated in Crete, Peloponnese (65%), the Aegean islands, the mainland Greece, and then the Ionian islands.
Italian olive oils are categorized according to the following D.O.P.s (denominations of protected origin): Aprutino Pescarese, Brisighella, Bruzzio, Colline di Brindisi, Colline DI Salernitane, Penisola Sorrentina, Riviera Ligure, and Sabina. Olive oil from the Chianti region has the prestigious denomination of controlled origin (D.O.C.) as well as D.O.P. Among the many different olive varieties used in Italy are Frantoio, Leccino Pendolino, and Moraiolo. Extra virgin olive oil is exported everywhere -- and often mixed to produce pure. The oil, specifically from Bitonto, is held in highest regard. Demand for Italian olive oil has soared in the United States. In 1994, exports to the US totaled 28.95 million gallons, a 215% increase from 1984. The United States is Italy's biggest customer, absorbing 22% of total Italian production of 131.6 million gallons in 1994. A 45% increase in 1995-6 is blamed for a drop of 10% in sales in Italy, and a 10% decline in exports to the US Despite shrinkage in production, Italian experts of olive oil rose by 19.2% in 1995 vs. 1994. A large share of the exports went to the European Union, especially Spain.
The United States is not a member of the IOOC, and the United States 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 IOOC existed. The California Olive Oil Council, a private US trade group, is petitioning the Department to adopt terminology and practices that shadow the IOOC's rules.
Global olive oil market
The main producing countries in 2003 were:
|Country||Production||Consumption||Annual Per Capita Consumption ( kg)|
|North Africa (mainly Tunisia and Morocco)||4%||4%||10.9|
Olive oil extraction
Traditionally, olive oil was produced by beating the trees with sticks to knock the olives off and crushing them in stone or wooden mortars or beam presses. Nowadays, olives are ground to tiny bits, obtaining a paste that is mixed with water and processed by a centrifuge, which extracts the oil from the paste, leaving behind pomace.
Relation to human health
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 two tablespoons (23 grams) 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 omega-3 fatty acids and walnuts which also contain monounsaturated oil.
A health study in 2005 compared the effects of different sorts of olive oil on arterial elasticity. Probands 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 probands received polyphenol-rich oil ("extra virgin" oil contains the highest amount of polyphenol antioxidants), during the second, they received oil with only one fifth the phenolic content. The elasticity of the arterial walls of each proband was measured using a pressure sleeve and a Doppler laser. It was discovered that after the probands had consumed olive oil high in polyphenol antioxidants, they exhibited increased arterial elasticity, while after the consumption of olive oil containing less polyphenols, they exhibited no significant change in arterial elasticity. It is supposed 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 ailments in regions where olive oil and olives are consumed on a daily basis.
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 (EVOO) 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 EVOO, castor oil (or another suitable carrier oil) and a select blend of essential oils.
Besides food, olive oil has been used for medicines, as a fuel in oil lamps, to make soap, as bodily decoration and as a sexual lubricant. The importance and antiquity of olive oil can be seen in the fact that the word "oil" actually derives from the same root as "olive".
The olive tree is native to the Mediterranean basin; wild olives were collected by Neolithic peoples as early as the 8th millennium BC and made into oil by 4500 BC in Palestine.
It is not clear when and where the olive tree was first domesticated: in Asia Minor in the 6th millennium; in Palestine or Syria in the 4th; or somewhere in the Fertile Crescent in the 3rd. Recent genetic studies suggest that modern cultivars descend from multiple wild ancestors, but the detailed history of domestication is not yet understood.
Olive trees were certainly cultivated by the Late Minoan period (1500 BC) in Crete, and perhaps as early as the Early Minoan period. The cultivation of the olive tree in Crete became particularly intense in the post-palatial period, and played an important role in the island's economy. From Crete started the first export of the olive oil not only to mainland Greece but to Northern Africa and Asia Minor as well. 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 oil was thus very common in Greco-Roman 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 Cretans were also the first Greeks to use the oil to anoint themselves while taking exercise in the gymnasia. The practice was intended 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 Greece, together with naked athletics, and lasted close to a thousand years despite its great expense.
Olive trees and oil production in the Middle East can be traced in the archives of the ancient city-state Ebla, around a dozen documents, dated 2400 BC, describing lands in the property 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. Many of the tablets dealt with administrative and commercial affairs. The tablets that have been consolidated by fire included the first known bilingual dictionary. These tablets use cuneiform script and are written in many languages. The kingdom of Ebla (2600-2240 BC) was located on the outskirts of the Syrian city Aleppo.
Olive Oil was also used by the ancient Hebrews. Olive oil of the highest purity was poured daily into the seven cups of the golden candelabrum (called the Menorah) in the Holy Temple in Jerusalem. Olive oil was also used for anointing the kings of the kingdoms of Israel and Judah. From this ritual of anointing, the expected savior of the Jews is called the Messiah (מָשִׁיחַ "anointed one"—mashiach). The word Christ (Greek Χριστός, Khristos, "the anointed one") is a literal translation of "mashiach".
Olive oil in contemporary religious use
Used as a medicinal agent in ancient times, and as a cleanser for athletes (athletes in the ancient world were slathered in olive oil, then scraped to remove dirt), it also has religious symbolism related to healing and strength and to "consecration" -- God's setting a person or place apart for special work. The Catholic and Orthodox Churches use olive oil for the Oil of Catechumens (used to bless and strengthen those preparing for Baptism), Oil of the Sick (used to confer the Sacrament of Anointing of the Sick), and 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. 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.
To this day, Eastern Orthodox Christians use oil lamps in their churches and home prayer corners. To make a vigil lamp a votive glass with a half-inch of water on the bottom is filled the rest of the way with olive oil. The votive glass is placed in a metal holder; different kinds of metal holders may hang from a bracket on the wall, or one that sits on a table. A cork float with a wick is placed in the glass and floats on top of the oil. The wick is then lit. When it comes time to douse the flame, the float can be carefully pressed downward into the oil, and the oil douses the flame.
Olive oil is also recommended by Muhammad the Prophet of Islam. “Consume olive oil and anoint it upon your bodies since it is of the blessed tree.” He also stated that it cures seventy diseases. Olives are also mentioned in the Qur’an as a sacred plant "By the fig and the olive, and the Mount of Sinai, and this secure city." .
Olive oil has a specific gravity of 0.915-0.919 (15.5 °C); a refractive index of 1.4657-1.4667 (15.5 °C); and a viscosity of 466.81 millipoise (27 °C).
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