Optimization of a New Knife Crusher to Increase Olive Oil Quality

Olive crushing has the purpose of breaking the olives, creating a paste made up of all the vegetable parts, suitable for subsequent processing. The crushers hit the drupe violently, transferring part of their kinetic energy. However, the shape, geometry and speed of the crusher tool can also produce a different way of breaking up plant tissues due to the different combination of compressive, shear and friction forces and different temperature of the olive paste. To increase the performance of this stage, a new knife crusher was studied. Specifically, a new knife rotor was studied to replace the hammer rotor and implemented in a traditional crusher. The aim was that of a preliminary optimization of the specific energy based on a new configuration of the blades to crush the olives, so to avoid an excess of temperature increasing into the grid. As a reference the results obtained were compared with those of a traditional hammer crusher. Test results reported an increase in the phenolic content of the olive oil when knife rotor was used, while about the olive oil extractability of the no significative difference was found between the two crushers compared.