Introduction: olive oil
Olive tree: botanical aspects and cultivation
Mature olive composition, nutritional properties
Olive harvest
Olive oil: chemical composition
Olive oil: properties and nutritional characteristics
Preparation of olive oil
Olive oil conservation
Pomace oil
Classification of olive oils, analysis and fraud
Olive oil as a laxative
Olive in herbal medicine - sea buckthorn
Cosmetic use: olive oil - Unsaponifiable with olive oil - Olive leaf extract
The extraction of oil from olives is done mainly with three systems:
- for pressure (classic, discontinuous method)
- by centrifugation (modern, continuous method)
- percolation by selective filtration (modern, continuous method)
METHOD BY PRESSURE : classic and ancient, has the disadvantage of being discontinuous.
The olives that reach the mill must first be cleaned of leaves, soil and anything else that could damage the organoleptic characteristics of the oil and the plant itself. The drupes will therefore undergo one or more passages in suction machines and washing tanks. Also at this level, for the production of particularly fine oils, a selection can be made by hand, removing the olives that do not meet the quality standards.
Immediately after cleaning the olives, the milling or crushing is performed, that is their crushing with mechanical means. The drupes are put inside the mullers (special metal tubs equipped with 2, 3 or 4 very heavy granite wheels, which turn on themselves and around a central tree, from which they distance in different measure, thus determining crushing the olive).
The purpose of the pressing is to damage the pulp cells, favoring the leakage of oil from the vacuoles and the crushing of the stone. This last aspect is very important because, being the core equipped with a woody shell, when it comes to breakage it produces splinters that favor, in turn, the lesion of the cellular structures of the pulp and a greater extraction of oil.
In the most modern mills, the grinders or mullers are replaced by metal breakers with hammers, cylinders or disks, which make it possible to reduce production times.
NOTE
An oil with a very high acidity is called lampante, it is not suitable for human consumption (it has an unpleasant taste), and is subjected to a series of processes to make it so.
Vegetation water is used for fertigation, ie it is spread in the fields and, being rich in minerals and nitrogenous substances, increases the fertility of the soil.