La qualità degli oli vergini in funzione delle macchine utilizzate per la preparazione della pasta di olive

Quality of virgin olive oil as function of the machines utilised for olive paste preparation. The mechanical extraction of the oil from the olives involves, as initial fundamental operation, with the preparation of the olive paste by means of various machines - different one from the other both in the processing principle and in the building characteristics - influencing the quality of the extracted oil. On the basis of such possible mechanical and technological variables experimental trials on olives milling has been carried on in different processing conditions using four different kinds of machines in order to verify their efficiency:a stone mill, a hammer crusher, a disk crusher and a depicking machine. On all the extracted oils the traditional analyses have been performed provided by the EC Regulation n. 2568/91, those relative to the content of total phenols and to the resistance to forced oxidation. The achieved results suggest suitable rules of selection of the machines in relation to the characteristics of the olives too, and improvements in the building techniques of the olive oil extraction machines. These techniques on one hand tend to increase the dispersion of the thermal energy developed in the crushing or roller milling cases, on the other to reduce the absolute amount of energy produced with the removal of the whole pit. The whole with the main aim of producing high quality and highly preservable virgin oils.