Introduction

The olive tree, one of the oldest known cultivated trees, is the symbol of friendship and peace; it also plays other social and religious roles described in Greek mythology and the Old Testament. More than 1275 autochthonous olive cultivars are identified and characterized (Bartolini et al., 1998) from an ancestor that is still subject to debate, but its origin is dated circa 5000 years ago though controversy also exists about its possible geographical origin in Mesopotamia. Nevertheless, Phoenicians and Greeks were responsible for the spread of the olive tree to Western regions where they traded.

The growth of olive oil cultivation was followed by the development of olive processing. The squeezing of olives in stone mortars, operated by early farmers, was not suitable for the increasing trade of olive oil in the Roman Empire. Romans decisively contributed to technological development with the milling crusher, which expedited the crushing process, and the wooden or iron manually activated screw press. They represented the major revolution in olive processing until Joseph Graham (1795) invented the hydraulic pressing system. The third revolution was in the second half of the twentieth century with the centrifugation system. The cost reduction of fully automated systems, which produce high-quality olive oils, the industrialization of agriculture, and the nutritional benefits of consuming olive oil abruptly increased olive oil demand and hence, olive oil production.

Nowadays, 600 million productive olive trees grow on the Earth and are spread out on 7 million ha, with pedoclimatic conditions such as those prevailing in the Mediterranean countries that account for not less than 97% of world production. The European Union is the major producer and also consumer, and surprisingly the number one exporter and the number two importer. Olive oil is marketed in accordance with the designations of the International Olive Council trade standards (IOC. 2006). Thus, virgin olive oil must be obtained by only mechanical or other physical means under conditions, particularly thermal, which do not lead to alterations in the oil. This oil has not undergone treatment other than washing, decantation, centrifugation, and filtration. Extra-virgin olive oil (EVOO) and virgin olive oil (VOO) are different edible grades of virgin olive oil. Lampante VOO is not fit for consumption and is intended for refining or for technical purposes. Refined olive oil (ROO) is the oil refined by methods that include neutralization, decolorization with bleaching earth, and deodorization. Olive oil is an edible blend of VOO and ROO. Olive–pomace oil is obtained by solvent extraction of the olive milling by-products; its triacylglycerol composition is similar to that of VOO, but some of the nonsaponifiable compounds (e.g., waxes) may differ significantly requiring the oil to be winterized before refining. Olive–pomace oil designation means a mixture refined olive-pomace oil with virgin olive oil. The result is that olive oil is the most controlled edible oil, overseen by numerous chemical standards and regulations (Table 1.1) that protect consumers against false copies.