Processes and extraction steps
The extraction technjque of olive oil dates from antiquity . it has not experienced any major changes even if it has evolved over the centuries, the basic principle has always remained the same . despite the many innovations of the material that have succeeded until the modern era. Industrial production has not eradicated the traditional method.
The method of extracting oil is purely mechanical, which means that the final product is pure fruit juice which has undergone no chemical transformation.
The steps and the basic operation of the production of olive oil are always :
- Washing and milling the olives.
- Grinding : crushing the olives into paste
- Pressing: it is to press the paste to extract the oil.
- Decanting: to separate the oil from the other elements (water, margins , debris ...)
There are two techniques of extraction :
- The traditional extraction
- The modern extraction.
The extraction in "AGROMED"
The performance of our oil mill stems from the diversity of our production systems. Equipped with all kind of machinery whether traditional or modern , it would allow us to meet the demands and wishes of our customers. They will have the choice between the traditional extraction and the modern extraction, which will enable us to always be at the top of the competition rank. And as already mentioned, the production steps are the same except that Ben Fredj family bears much passion and care in the process of transformation to preserve the virtues of its hygienic and nutritious oils.
1- Culling and sorting
After the ripe olives have been combed from the trees. At Ben Fredj area, they are picked over by hand with plastic brushes to weed out unsound olives and avoid damaging the seeds. The olives fall on the extended curtains under the tree and are then placed in natural bags halfah grass bags.
2- Washing and milling the olives
Transportation of the olives to the oil mill the same day as the collection to ensure the freshness of the seeds. Our olives are then washed with a source water from the region and are carefully sorted. Any foreign objects such as stones, leaves , sand, overripe or damaged olives are eliminated.
This is the first extraction step where olives are processed into a paste.
Traditional methods "Stone olive mills"
They are crushed by a huge millstone , an instrument used for millennia, and which the speed of milling is a bit limited.
Modern methods "Hammer Mills"
Modern and faster instruments are used , metal hammer mills ; Small hammer tap olives on a wire rack and burst. The olives are processed into pulp, olive pits are still present but crushed. The paste should be malaxed in order to allow a better extraction of olive oil.
Classical methods "Hydraulic olive press"
Like a hydraulic car jack, the piston squeezes the paste which has been applied to stacks of filter like discs. This is the last extraction step , the paste is cold pressed using a hydraulic press to separate the oil from the pomace.
Modern processes: Mixing rather than pressing
This is an operation that follows the milling or pressing and is intended to break the emulsion between the water and the oil and the oil particles agglomerate into larger drops , separating spontaneously water vegetation. It is carried out in a mixer , a steel tray , cold (temperature 23 ° C) . The oil pockets are formed gradually on top of the paste. When the paste is ready , it passes into the separator in a centrifuge which power is 4100 tours/minute.
5- Separating the oil from the vegetable water
Classic methods "natural extraction"
The extracted juice is collected in decanting ponds and it is immediately filtered to separate the oil from the water and remove the residue (pomace , solid fractions consist of fragments of core and pulp). This is the most important and most delicate stage of extraction. Decanting is made naturally.
Modern methods "centrifuges"
The centrifuge is a modern tool. The olives are crushed by metal blades. Then, the paste undergoes the work of the centrifuge to extract the oil.
Horizontal centrifugation : Separation of solids and liquids.
Vertical centrifugal : Separation of liquids; water and oil.
Finally, the oil is stored in food in stainless steel tanks at a controlled temperature, away from light and air to preserve its freshness, taste and fruity flavor and to prevent oxidation.
The process of extracting oil from the oil mill adopted by "AGROMED" meets the requirements of organic standards and carefully follows the key steps:
harvesting, sorting, washing and grinding, pressing and settling and storage. The resulting oil is an authentic extra virgin olive oil.