by Mueller, Tom
Wine is how we would like life to be, but oil is how life is: fruity, pungent, with a hint of complex bitterness—extra virginity’s elusive triad.
GLOSSARY
For a more in-depth glossary of olive oil terms, see www.extravirginity.com.
Antioxidant – A substance that inhibits oxidation, i.e., a chemical reaction with oxygen. Oxidation, though vital for biological systems, can also produce free radicals and cause cell damage; therefore, plants and animals typically employ antioxidants to reduce oxidative stress. Extra virgin olive oil contains a number of antioxidants, including tocopherol (vitamin E) and a range of polyphenols.
Bitter – One of the three characteristics, together with fruity and peppery (or pungent), which are mentioned as desirable in the definition of extra virgin olive oil endorsed by the IOC, the EU, the USDA, and many other institutions. Bitterness is often associated with the presence of antioxidants and other health-promoting constituents of the oil. A recent survey of olive oil consumers in northern California performed by UC Davis sensory scientists revealed that the majority of consumers disliked oils with marked bitterness or pungency, in sharp contrast to olive oil experts.
Cold-pressed – An outdated production term, now used for marketing purposes and largely devoid of meaning. Until a half-century ago, when oil was made with hydraulic presses, after the first pressing had removed the best oil, the nearly spent paste was drenched with hot water (as Saint Sanctulus of Norcia taught) and pressed again, yielding a second-press oil of inferior quality. Nowadays, extra virgin olive oil is “first-pressed” and “cold-pressed” almost by definition. (EU regulations state that “cold-pressed” can be used only when the olive paste is kept at or below 27 degrees Celsius during the malaxing process—a level respected by nearly all serious producers—and when the oil is actually made with a press, nowadays a rare occurrence.)
Crush, crushing – See Extraction and Milling.
Cultivar – A distinct variety of olive (or other fruit or vegetable) and of olive tree, which has arisen through selective cultivation, often over many centuries. There are approximately 700 olive cultivars in the world, which frequently have strongly divergent agronomic properties, and produce oils with distinctive sensory, chemical, and nutritional properties. Some of the most commonly grown cultivars are: arbequina, ascolana, barnea, chemlali, chétoui, cobrancosa, coratina, cornicabra, empeltre, frantoio, galega, hojiblanca, koroneiki, leccino, maurino, manzanillo, memecik, mission, pendolino, picholine, picual, picudo, sevillano, souri, and taggiasca.
Deodorized oil, mild deodorization – Olive oil, typically of low quality, that has undergone a refinement process to remove unpleasant odors and flavors. By law such oil can only be sold as refined olive oil, but it is frequently sold, illegally, as extra virgin oil. Many cheap supermarket oils worldwide consist in large part of deodorized oil. One of the most popular deodorizing methods is the SoftColumn refining system by Alfa Laval, the leading producer of extraction equipment for olive oil and other vegetable oils; the company markets SoftColumn for seed oils, but it is reportedly used widely to deodorize olive oil as well. Because deodorization is done at far lower temperatures (40–60 degrees Celsius) than normal refining, and because a number of different deodorizing techniques exist, deodorization is often difficult to detect with chemical tests. New chemical analyses have recently been introduced (a ceiling on the amount of alkyl esters by the EU, measurement of DAGS and PPP by the Australian Olive Association) that should help to reduce the prevalence of deodorized oil—or at least force unscrupulous oil producers to develop new methods of deodorization.
Drupe – The botanical term for a fleshy fruit that usually contains a single hard stone, inside which is a seed. Drupes include olives, cherries, plums, and peaches.
Extraction – A process by which oil is removed from olives (as well as other fruits, nuts, and seeds). Two major types of extraction exist for olive oil, mechanical and solvent extraction, of which the mechanical process alone is allowed for extra virgin oil. In mechanical extraction, the olives are crushed (see Milling), the resulting paste is stirred to allow oil microdroplets to coalesce (see Malaxing), after which the oil is separated from the paste with a centrifuge or press. In modern extraction systems, centrifuges have replaced hydraulic presses as the technology of choice because they are more efficient and easier to keep clean. Nowadays very few quality oils are made with presses. (See also Cold-pressed.) Solvent extraction is widely used in making seed oils and in olive pomace oil.
Extra virgin – The highest quality grade of olive oil, which according to standards established by the IOC, the EU, and other governing bodies, must meet a series of chemical requirements (free fatty acidity of 0.8 percent or lower, peroxides at less than 20 milliequivalents per kilogram, etc.), and be able to pass a panel test which demonstrates both that it possesses some detectable level of olive fruitiness, and that it is free of taste flaws.
Fat – An organic compound, derived from the adipose tissues of animals and of the fruits, nuts, and seeds of plants, which is made up primarily of triglycerides, free fatty acids, and associated organic groups. The terms “fat,” “oil,” and “lipid” are largely interchangeable, though in common usage a fat is solid at room temperature, an oil is liquid at room temperature, and a lipid comprises both fat and oil.
Fatty acids, free fatty acids – Members of a large group of organic acids, particularly those found in animal fats and vegetable oils, which consist of a carboxyl group (COOH) and a chain of carbon and hydrogen atoms, most of which vary from four to twenty-eight carbon atoms in length. The general chemical formula of fatty acids is CnH2n+1COOH. When not attached to other molecules, fatty acids are called free fatty acids. Fatty acids may be saturated or unsaturated; unsaturated fatty acids, in turn, are divided into monounsaturated and polyunsaturated fatty acids. The fatty acid composition of olive oil varies depending on many factors, including the olive cultivar, climate, and fruit maturity. The primary fatty acids present in olive oil are oleic acid, which makes up between 50 and 80 percent of most olive oil, together with linoleic acid, and palmitic acid.
Filtration – The process of removing sediment—tiny bits of olive pulp, pit, and skin—suspended in the oil, as well as making an oil more brilliant by running it through a cloth or mesh filter. There is considerable disagreement even among producers about the importance of filtration: improper filtration can attenuate certain flavors and aromas, and many makers of fine oil prefer simply to rack their fresh-pressed oil repeatedly. Other top oil-makers swear by filtration, which can significantly increase an oil’s shelf life and seems to improve its stability during storage.
First-press – An outdated term, now used for marketing purposes and devoid of meaning. A half-century ago, when oil was made with hydraulic presses, after the first pressing the nearly spent paste was sloshed with hot water and re-pressed, producing an inferior second-press oil. Nowadays, extra virgin olive oil is “first-pressed” and “cold-pressed” almost by definition.
Flavored oils – Olive oils flavored with extracts from a range of fruits, vegetables, and other agricultural products. The best are made by crushing whole fruits or peels (typically of citrus fruit) together with the olives, a process called agrumato. Other flavored oils are made by steeping fruit peels in olive oil or by adding extracts to the oil, the latter being the quick-and-dirty method of producing flavored oils.
Flaws, defects – Official off-flavors (and odors) in olive oil that are listed in olive oil legislation and quality protocols, and that, if present, help to determine the quality grade of the oil. They indicate the poor quality of an oil, often caused by unhealthy or overripe fruit, flawed milling techniques, faulty storage, or other errors in the oil-making chain. The sixteen official taste flaws listed by the IOC and in EU law are: fusty (or atrojado), mustiness/humidity, muddy sediment, winey/vinegary, metallic, rancid, heated or burnt, hay/wood, rough, greasy, vegetable water, brine, esparto, earthy, grubby, and cucumber.
Free fatty acidity (FFA), free acidity – An important chemical parameter for determining the quality of an olive oil, which is part of the olive oil grading system of the IOC, the EU, the USDA, the Australian Olive Association, and many other bodies that oversee olive oil quality. FFA measures the percentage by weight of the free oleic acid (see Fatty acids, Oleic acid) contained in a sample of olive oil. In general terms, FFA indicates the breakdown of the basic fat structure of an oil, whether because of poor-quality fruit (due to bruising, olive fly infestation, fungal attack) or, most commonly, by delays between the harvest and the crush. Although a low FFA is no guarantee of good quality, as a rule of thumb the higher the FFA, the more likely the oil is to be of poor quality. The level of 0.8 percent FFA set by the IOC and other regulatory bodies for the extra virgin grade is far too high to guarantee good oil: excellent extra virgin oil frequently has an FFA of 0.2 percent or lower, and anything over 0.5 percent is likely to be inferior.
Fruity – One of the three characteristics, together with bitter and peppery (or pungent), which are mentioned as desirable in the definition of extra virgin olive oil endorsed by the IOC, the EU, the USDA, and many other institutions. Fruity refers to a taste or aroma reminiscent of fresh olives. An olive oil must demonstrate some level of fruitiness in order to be legally eligible for the extra virgin grade.
Fusti (Italian fusto, “tank” or “barrel”) – Stainless steel containers used to store olive oil (as well as wine and other products), typically having a large lid on top that screws off and on.
Hydrogenation, hydrogenated, partially hydrogenated – Refers to a vegetable oil that has undergone the industrial process of hydrogenation, during which the oil is heated to 250–400 degrees Fahrenheit, a metal catalyst is added, and hydrogen is bubbled through it. As a result, the fatty acid chains in the oil are artificially saturated with hydrogen atoms, which straightens the chains by removing the kinks that naturally occur at the sites of double bonds. Full hydrogenation yields a fat that is too hard for convenient use in food production, so the process is usually interrupted when the fat is only partially hydrogenated, resulting in a product that is firm but malleable at room temperature and melts when cooked or eaten. The resulting partially hydrogenated (or hydrogenated) fat is a trans fat, and has significant health risks when eaten.
Hydroxytyrosol – A polyphenol and powerful antioxidant contained in olives, olive oil, and olive leaves. Its use as a supplement or preservative is being explored by the nutraceutical, cosmeceutical, and food industries. Recent experimentation suggests that hydroxytyrosol, thanks to its potent antioxidant activity, helps prevent DNA damage and the harmful oxidation of LDL (“bad”) cholesterol; medical research also suggests that it works against cardiovascular disease by inhibiting platelet aggregation and pro-inflammatory enzymes.
Invaiatura – The Italian term (in English, the French term véraison is often used) for the phase in the maturation of the olive, and other fruits, during which the green coloration of the young, unripe fruit gives way to the darker oranges, reds, and purples of more mature fruit. Many olive growers use the invaiatura as a signal to begin their harvest, because it marks a balance between the marked flavors and aromas of young, early harvest fruit and the higher oil content of later-harvest fruit.
IOC – International Olive Council, an intergovernmental agency instituted by the United Nations in 1959, aimed to supply aid and advice to growers and millers, fund research in oil quality and chemistry, and promote olive oil consumption worldwide. The IOC currently has forty-three member nations (counting the EU and EU nations), olive-growing and oil-producing countries primarily located around the Mediterranean which make 98 percent of the world’s olive oil.
Lampante – Literally “lamp oil,” from the Italian lampa (“lamp”), lampante is the lowest grade of olive oil in the quality grading system of the IOC. By law it is unfit for human consumption, and must be refined before it can be sold as food.
Light olive oil – A marketing term for refined olive oil. See also Olive oil, Pure olive oil.
Linoleic acid – One of the main fatty acids in olive oil. Linoleic acid is polyunsaturated, and constitutes anywhere between about 4 and 21 percent of most olive oils.
Linolenic acid – One of the main fatty acids in olive oil. Linolenic acid is polyunsaturated, and constitutes up to about 1.5 percent of most olive oils.
Malaxer, malaxing – The second major phase of the olive oil extraction process after milling, during which the olive paste made from ground-up olives is mixed or stirred to allow the microdroplets of oil in the paste to coalesce into larger drops that are more easily extracted. A modern malaxer is a stainless steel trough with a fan screw turning along the bottom. Malaxing lasts twenty to forty minutes, depending on the cultivar, the condition and ripeness of the olives, and other factors. Shorter malaxing times help minimize oxidation and free acidity, while longer times increase oil yield and may improve oil flavor but typically reduce shelf life. (The term is derived from the ancient Greek malassein, “to make soft.”)
Milling – The first part of the oil extraction process, in which olives are ground or crushed using one of several different machines. Traditional mills used millstones in a number of different shapes, originally turned by animal or hydraulic power and later by motors. Motor-driven millstones are still widely used, though they are being replaced by crushing devices that grind the fruit with stainless steel hammers, disks, and other mechanisms, which cause less oxidation of the oil.
Oil – Generally speaking, an oil is a fat that is in a liquid state at room temperature.
Oleic acid – The primary fatty acid in olive oil, which is monounsaturated, and constitutes between 50 and 80 percent of most olive oils. Because of a lipid profile that is relatively resistent to oxidation, oleic acid gives olive oil a longer shelf life than most other oils. Oleic acid has been associated with some of the major health benefits of the Mediterranean diet, such as a reduced incidence of coronary heart disease and cancer, and a 2005 study done at the Northwestern University Feinberg School of Medicine showed that oleic acid can cripple a gene that causes 25 to 30 percent of breast cancers.
Oleocanthal – A polyphenol that naturally occurs in quality extra virgin olive oil, which is a strong antioxidant and a powerful anti-inflammatory with properties that resemble those of ibuprofen. The peppery throat-sting caused by oleocanthal, first discovered by a team of Unilever scientists and later studied in detail by Gary Beauchamp and colleagues at Monell Chemical Senses Center, is also very similar to that caused by ibuprofen. Research has revealed that many olive oils contain comparatively large quantities of oleocanthal, and suggests that the substance may have therapeutic effects against coronary heart disease, stroke, cancer, Alzheimer’s disease, and other conditions.
Olive oil – A marketing term for refined olive oil that has been blended with a small amount of extra virgin olive oil to give it flavor. See also Light olive oil, Pure olive oil.
PAHs (polycyclic aromatic hydrocarbons) – A family of chemical compounds formed during the incomplete combustion of organic substances, which have been shown to cause cancer as well as genetic and neurological damage. While trace amounts of PAHs are present in many foods, illegally high levels of PAHs have been detected by European health officials in certain olive pomace oils.
Palmitic acid – One of the main fatty acids in olive oil, palmitic acid is saturated, and constitutes between 8 and 20 percent of most olive oils.
Panel test – The official sensory analysis of olive oil, performed by a taste panel, which, together with a battery of chemical analyses, is part of the legal method for determining the quality grade of a given sample of olive oil.
PDO (“Protected Designation of Origin,” DOP in Italian) – A legal designation by the European Union, similar to the Appellation d’origine contrôlée designation in French wines, for foods that are produced or processed in a specific region using traditional production methods. One of these foo
d products is extra virgin olive oil; a number of PDO oils have been designated in Italy, Spain, Greece, and elsewhere in southern Europe. The production process of PDO oils is laid down by a specific protocol and overseen by a quality control committee, which helps to ensure the quality of the oil. PDO status is legally binding within the European Union, and is gradually being extended via bilateral agreements to areas outside the EU.
Peppery (or pungent) – One of the three characteristics, together with fruity and bitter, which are mentioned as desirable in the definition of extra virgin olive oil endorsed by the IOC, the EU, the USDA, and many other institutions. Pepperiness is often associated with the presence of a number of health-promoting constituents in the oil. A recent survey of olive oil consumers in northern California performed by UC Davis sensory scientists revealed that the majority of consumers disliked oils with marked pungency or bitterness, in stark contrast to the preferences of experienced olive oil tasters.
Peroxides – An important chemical parameter for the quality of olive oil, which is part of the olive oil grading system of the IOC, the EU, the USDA, the Australian Olive Association, and many other olive oil bodies. Generally speaking, an oil’s peroxide value indicates the extent to which it has been oxidized, typically through degradation by free radicals or by exposure to light. The peroxide levels for the extra virgin grade set by the IOC and many other bodies—less than 20 milliequivalents per kilogram—are far too high to guarantee good oil, which frequently has peroxides at well below 10 meq/kg.