Olive oil 101

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About Defining Olive Oil Quality

In 1959 the I.O.O.C. (International Olive Oil Council) was formed under guidance of the United Nations with the task of proposing rules and regulations overseeing the quality of Olive Oil and providing statistics for lawmakers. Its head office is in Madrid, Spain, then and now by far the most important olive oil-producing country in the world. As the EUproduces and consumes about 75% of the world’s olive oil, the EU laws concerning the quality olive oil are the most relevant and became the world’s standard. The most important quality categories as proposed by the I.O.O.C. and made into law by the EU since 2004 and which must now be explicitly mentioned on the labels of all olive oil containers, are the following:

Extra Virgin Olive Oil (highest quality)

This Olive Oil must be obtained through a first extraction or pressing by mechanical means at less than 27º C. from fresh and healthy fruits. The natural acidity (the amount of free fatty acids expressed as a percentage of oleic acid) may not exceed 0.8% and the peroxide index may not exceed 20 meq/kg. There are more conditions to be met, but these are the most important.

Virgin Olive Oil (lower quality)

Same as above, but the natural acidity may not exceed 2.0%. This higher acidity can be caused by many reasons. The fruits may not have been that healthy or had been badly stored between picking and milling or the Extra Virgin olive oil ran out of best before date or had been exposed to air or light. Virgin Olive Oil will show slight defects of odour and taste. Reason why this type of olive oil, often in combination with Refined Olive Oil, is the prime choice for the production of industrial “aromatic” olive oils, infused with herbs and spices. Olive oil is known to readily absorb foreign odours, good or bad.

Lamp Olive Oil (not fit for human consumption)

This denomination will include any olive oil with a higher acidity than 2.0% including virgin olive oil which has been contaminated and developed a bad odour or taste. Lamp Olive Oil is considered not fit for human consumption. Some statistics show that in the Mediterranean area, because of poor harvesting conditions, up to 50% of the crop falls into this category. A long time ago Lamp Olive Oil was used for burning in lamps, but now it is collected by refineries for purification.

Refined Olive Oil (low quality) obsolete: Pure Olive Oil

This concerns olive oil produced in a refinery from Lamp Olive Oil by means of chemical and physical filters as well as neutralization, bleaching and deodorization techniques. The end product is odorless, colorless and tasteless, devoid of any vitamins or anti-oxidants and its acidity artificially set at < 0.3%, but physically it is still olive oil. In this form it is sold to fish canneries for conservation of sardines, mackerel, squid, anchovies, etc., but the major part by far is mixed with typically 15% Extra Virgin Olive Oil or Virgin Olive Oil and sold to industrial users, professional kitchens and supermarkets at a discount for baking and frying.

Refined Olive Pomace Oil (lowest quality)

This olive oil is produced in a distillery by means of hexane or heptane extraction at high temperatures. The raw material is not Lamp Olive Oil but rather the semi-solid olive cake called Pomace, which is left in the centrifuge after milling. It mainly consists of crushed olive seeds, but it still contains some oil, which can only be extracted by chemical means. Also spent filter sand, saturated with olive oil, which mills used to instantly remove tiny fruit particles, is a source of raw material for the distilleries. The physical appearance of Pomace Olive Oil is the same as with Refined Olive Oil and the acidity is artificially set at < 0.3%. Also the end users are the same as with Refined Olive Oil with the addition of the cosmetics industry.

Hazard of PAW’s in Refined Olive Oil and Refined Olive Pomace Oil

There is one problem however: because of the high temperatures applied during the industrial process, a group of totally new chemical compounds is formed, both in Refined Olive Oil and even more so in Refined Olive Pomace Oil, called Polycyclic Aromatic Hydrocarbons (PAH’s), which are potentially carcinogenic. The level of the worst offender, a heavy PAH called benzo(a)pyrene, serves as a marker for the presence of other PAH’s of which fluoranthene, anthracene and chrysene are the most important. Unfortunately, these intruders can only be removed from the oil at high cost. Officials from olive oil producing countries have negotiated for years with the I.O.O.C. and law makers in Brussels to set a “safe” benzo(a)pyrene norm for human consumption of olive oil (presently max. 2 µg/kg in all edible oils). One way of lowering the benzo(a)pyrene content to legal levels is by mixing Pomace Olive Oil and Refined Olive Oil with some Virgin Olive Oil and/or Extra Virgin Olive Oil for baking and frying.