Processo Estrazione Olio

Extraction

Extraction is the process of dividing the oil must – that is, the unfiltered liquid part – from the pomace – that is, the solid part containing fragments of kernels, peel and pulp. There are three methods for performing this process of extraction: extraction by pressure, extraction by centrifugation and extraction using the Sinolea method.

Extraction by pressure

This type of extraction is the most classic method, in which the paste obtained by kneading is spread on circular filtering diaphragms, arranged in a tower. These cylinders, which rotate on a pin, press the olive paste, forcing out the liquid part.

This type of extraction has its pros and cons:

PRO

  • The pomaces maintain a good quality
  • The energy and water used are reduced
  • The vegetation water to be disposed of is less than with the other systems
  • The vegetation water has a lower polluting load

CON

  • High labour costs
  • High costs of cleaning machines
  • Discontinuous operating cycle
  • Risk of deterioration of quality due to paste residues in the cylinders

Extraction by centrifugation

This type of extraction is part of the continuous cycle process. In this process, the pulp is pushed, together with a defined amount of lukewarm water, inside a cone-shaped centrifuge where, through a physical effect, the separation of the paste from the must takes place.

This process also has its pros and cons:

PRO

  • Low need for labour
  • High labour capacity
  • Low degree of oxidation, which leads to a discreet oil quality
  • Small footprint

CON

  • High costs of disposal of vegetation water and greater pollution
  • High drum maintenance costs
  • Greater water consumption

Extraction by the Sinolea method

This form of extraction consists of placing a device in a tank containing the oil paste. In order to separate oil and vegetation water, this process exploits the surface tension of the two elements involved: oil, which has a lower surface tension, tends to stick to the extractor, which has a metallic surface.

Like the other types of extraction, this technique also has its pros and cons:

PRO

  • Oil with a very high quality, due to the absence of alterations
  • Totally cold processing
  • Oil completely free of water, therefore does not require a centrifuge

CON

  • Low yields: little of the product is extracted