Microwave equipment to conditioning the olive paste instead of the malaxer
machine: prospective of industrial application in olive oil extraction plant
Alessandro Leonea, Roberto Romanielloa, and Antonia Tamborrinob
a
Department of the Science of Agriculture, Food and Environment, University of Foggia, Italy.
b
Department of Agricultural and Environmental Science, University of Bari, Bari.
Correspondence: Alessandro Leone, Department of the Science of Agriculture, Food and
Environment, University of Foggia, Italy. Via Napoli, 25 – 71100 Foggia, Italy. Tel.: +39
589120. E-mail: alessandro.leone@unifg.it
Key words: olive oil extraction equipment; microwave equipment; olive oil quality; electric
and thermal energy consumption; olive paste.
With the aim of improving the operation of the extraction plants towards providing a continuous
management of the process, a complete investigation regard the introduction of the microwave
apparatus in the olive oil extraction plant has been carried out. A new machine based on
microwaves technology was designed, built, implemented and tested in an industrial olive oil
extraction plant, to evaluate its potentiality in terms of qualitative-quantitative indices of the
extracted oil and in terms of power requirement for its employment.
A full evaluation of the microwaves machine was made and every measured parameter was
compared with those measured using the traditional malaxar machine. The knowledge of the
effects of the microwave treatment on the olive oil quality and yield as well as on the electric
and thermal energy consumption could be the first result towards a continuous olive oil process.
The experimental results showed the microwave’s ability to generate a thermal and a nonthermal effect on the olive paste, objectivised through the temperature increasing and the
vacuole desegregation respectively. Moreover, these combined effect promoted the oil drops
coalescence that is directly correlated to extraction efficiency. The quality evaluation of the
extracted oils highlighted that the microwave treatment do not affect the oil’s marketable
parameters. The energetic evaluation demonstrated the utility of microwaves technology for
olive pastes’ conditioning, in the intent to make the olive oil extraction process truly continuous.
This results could open new prospective for the innovation in olive oil extraction plants. In
addition, the olive oil quality obtained opens some considerations regard the operative
management of the process as well as on the mechanical solution of the plants. The future goal
could be to develop an integrated system conditioning the olive paste constituted by processing
technologies that perform the malaxing phase to obtain the optimum. In order to adapt the
extraction plants both to the olive characteristics (i.e. cultivar or maturation index) and to the
oil obtained could be useful the introduction of a “modular olive oil extraction plant” including
different olive paste conditioning equipment. The results acquired from the present study are
considered very promising for the future of this technology in this specific field.