Olive OilThe Green Gold

IntroductionThe cultivation of olives and the production of olive oil are spread mostly in the Mediterranean Area. The European Union has 70% of world production of olive oil. The major European producers are: Spain (45 %), Italy (16 %) and Greece (10 %). Outside the European Union the largest producer are: Syria and Tunisia. Italy produces about 550.000 ton. of olive oil and is the second largest in the world after Spain. The main Italian regions producers, in the order are: Apulia, Calabria, Sicily, Campania, Lazio and Abruzzo.

The Origin of Olive Trees and OilOlive trees appeared for the first time about 6.000 years ago in Asia Minor between the Armenian plateau, Turkestan and the Pamirs, from where it spread in Greece and later, thanks to the colonization, also in Sicily and in the mediterranean coasts. The olive oil extraction is an activity which has been with humankind since time immemorial.

From archaeological findings in Crete, it seems that olive oil was extracted through the crushing of the olives against a flat stone. The crushed olives were collected in basins and pressed with rudimentary stone mortars and presses. The juice dripped was collected in “Pithoi”, terracotta amphoraes used for the storage of olive oil.

Key factors in the cultivation of olive trees

• Soil and climate: Olive cultivation is indissolubly linked to Mediterranean climate, characterized by mild winters, hot dry summers and rainfall concentrated in the autumn and spring.

• Protection from pests and disease: The defense of the olive doesn't require a large number of interventions and, especially in cool climates, it can produce healthy olives with more than two pesticide treatments annually. The insect key in all Italian regions is the olive fly (olive fruit fly), whose larvae dig tunnels in the fruit pulp feeding.

• Pruning: Pruning is a necessary practice to be performed taking into account the prerogatives biological olive, including the natural behavior of the species and variety, the high vegetative activity, types of buds and branches, and the alternation of production.

Centuries-old olive treesIn Italy there are a lot of old olive trees especially in Apulia where they are really important for natural heritage, in fact there are about 15 million centuries-old olive trees and some exceed the thousand years. This year some ancient olive groves have been nominated to become World Heritage Site by Unesco. They have a very large trunk and they usually show irregularities caused by the various damages suffered over the time, some of them present such big cavities which would allow us to go inside. In Sicily there are Saracen olive trees planted by the Arabs more than a thousand years ago.

Ancient olive tree of Vernole, Apulia (1400 years old)

Ancient olive tree of Luras, Sardinia (4000 years old)

The importance of the olive harvestIn the production of oil each stage can determine the quality of the final product, and the harvest in fact must be done according to specific methods, and in the right period of maturation. The olives ripen usually in October, on the coast where temperatures are mitigated by the action of the sea, or in December and January, in the cooler and higher areas. In addition to the type of olives and temperature, the perfect time for harvesting varies according to seasonal weather conditions and growing techniques used. So it is important that the collection takes place at the appropriate time and with the most appropriate methods called: shaking, beating with poles, combing, spontaneous fall and hand picking.

Cultivar and different types of olive oilThe olives are similar but are not all equal. We talk of cultivars or varieties to indicate plants with genetic and morphological characteristics (scop, form and size) which produce several different olives and oils. From the cultivar depend three main characteristics of the oil that is: the fruity bouquet, feelings of bitterness and pungency. Finally the level of acidity indicates the quality of the oil.

Name Acidity Extraction methods

Extra virgin oil ≤ 0,8 It is obtained by extraction with only mechanical methods.

Virgin oil ≤ 2,0 It is obtained by extraction with only mechanical methods.

Refined oil ≤ 0,3 It is obtained by rectification of virgin lamp oils with physical and chemical methods and subsequent refining.

Pomace oil ≤ 1,0 It is obtained by wastes processing of the olives and refining.

Extraction of oilThe step of the olive oil production involves the extraction of oil from olives; this process is done in mills which use the method to traditional pressure or the method of extraction by centrifugation.

• Method to traditional pressure (batch process)• Method of continuous centrifugation with three-phase

system• Method of continuous centrifugation with two-phase

system• Method of continuous centrifugation to save water

Panel testAfter extracting the oil, and completed all the various processes of decantation, bottling etc it is necessary to taste it to see if it has the right characteristics for being considered a good oil. This task is given to the Panel test, it is an analysis that takes place in a tasting room where 8-12 exeperienced tasters, using a specific dark glass and staying

in a climate-controlled enviroment, express an opinion on the merits and defects of the virgin olive oil. The individual opinion (subjective) will then be processed to obtain the objective result of the entire group of tasters.

Olive Oil and HealthThe most interesting aspect of the fats contained by the olive oil is that thanks to its chemical quality, olive oil is healthy. The olive oil contains monounsaturated fatty acids, unsaturated and, with reference to the quality of long oleic fatty acid, olive oil is considered noble for its chemical properties and its value to food and nutrition. Polyphenols, compounds responsible for the flavour and aroma of the oil, are among the most powerful antioxidants which protect the human body from degenerative phenomena typical of aging inhibiting the formation of radicals free, with beneficial effects on the cardiovascular system, neurological and immune.

Made By Giuseppe RomanoScientific High School ‘Ernesto Basile’

Class 4^A