Extraction systems and olive oil

The ideal extraction method is the one that gives the highest yield of oil without altering the oil's original composition and quality. It is essential to use only mechanical methods, avoiding all chemical and enzymatic reactions. Mechanical extraction ir achieved by, 1) crushing the olive, 2) heating the resultant paste, and 3) separating the oil from vegetation water and pomace Crushing : crushing is designed to burst the flesh and kernel of olives and so let the droplets of oil run out of the cells. Beating : the paste is beaten to favour the separation of the liquid phases from solids and to break up oil-water emulsions. Extraction : a) Pressing. When the solid-liquid mass of the olive paste is subjected to pressure, the oily must is expressed and separated from the solid phase, b) Centrifugation. Centrifugation is a widely used method of separating the oil from the paste in industrial plants. c) Percolation. The oil adheres to a metal surface more than does the water. TI,is phenomenon is the basis of the percolation method of oil extraction from olive paste. Percolation is generally combined with centrifugation. The basic chemical and physical elements on which the final composition and quality of olive oil are determined, are discussed.