Performance testing of a full-scale ultrasound equipment for the extravirgin olive oil industrial sector

The basic principles applied also in the newest olive oil industria! plants still follow the technical knowledge which have been empirically learned by humans thousands of years ago. In fact, it is well known that three factors, mixing, water adding and warming, are the three macroscopic driving forces able to favour the separation of the oily phase from the mass of crushed olives. The perseverance into the optimization of existing machines composing the virgin olive oil extraction line offers reduced margins for the performance increment of the process. The aim of the experimentation supported by EU through the Apulia Region by means the project "Perform Tech (Puglia Emerging Food Technology) was to develop an innovative full scale device, based on the application of high power ultrasound into the olive paste, useful to reduce the malaxing time or replace the malaxing phase. In fact, the malaxation is considered the weakest link of the chain in the extra virgin olive oil extraction process. The malaxer is a batch machine, which works between two continuous devices, the fruit crusher and the decanter. lt is also a bad heat exchanger due to a not favorable ratio between the volume of olive paste and surface for the heat exchange. The aim of this paper is demonstrate that the new ultrasonic reactor, named sono-heat-exchanger, placed between the crusher and the malaxer is able to obtain a simultaneous increment ofboth oil yield and quality.