## 4 Conclusions  
Many solutions for improving quality and oil yields have been proposed during the last decade in the olive oil sector, but only few ideas have been transferred into the market. This paper illustrates the end-user validation of the application of ultrasounds in the extra virgin olive oil extraction process. The currently used technology often considers the oil yields and the quality, associated with -phenolic content and positive sensorial attributes, in antithesis. The results obtained in this research demonstrated an increase of oil yields and a reduction of the process time with a simultaneous preservation of the product quality, evaluated by validated methods. The total phenols and the total hydroxytyrosol content in EVOOs obtained from traditional milling and using the SHE system were comparable. Analogously, the sum of the molecules originating from the lipoxygenase (LOX) pathway (related to the green and fruity notes of VOOs) was not significantly affected by the application of the ultrasounds. On the contrary, the cultivar seems to affect the concentration of these molecules with highest values for Coratina cv. Anyway, no significant differences were highlighted between oils of the same cultivar obtained with or without the use of ultrasounds.  
Overall, the analytical results and the collaboration with the end-users have contributed to the assessment of the machine's usability by specific users.  
The validation of the innovation and its transferability to the olive oil sector has been demonstrated by placing the machine in different geographical areas, to study its behavior towards different cultivars and different degrees of maturation. The innovative technology combines the mechanical energy of ultrasounds with the possibility of modulating the thermal exchange of olive paste. It has been demonstrated able: (i) to eliminate the malaxation step by realizing an effectively continuous process, (ii) to raise oil extraction yields recovering a part of EVOO usually lost in olive pomace, (iii) to preserve the antioxidant phenols and volatiles from the LOX pathway responsible for the fruity and green notes of virgin olive oils, (iv) to offer a sustainable plant solution able to reduce the process time and to save energy (coherently with the goals of the 2030 agenda on sustainable development), thus guaranteeing the right income to the manufacturers.  
Furthermore, an added value of this work was the demonstration of the applicability of this mobile and flexible prototype machine (the SHE) in different plants produced by the world's leading manufacturers of oil machines. The implementation of the prototype in this sector will contribute to promoting the culture of innovation as a keystone for increasing the competitiveness of the olive oil production chain by developing technological solutions such as ultrasounds to improve the production cycle and the environmental and economic sustainability of the process.  
The following are available online, Figure S1: Spider web plot obtained by sensorial analysis of two samples, obtained by the same batch of olives processed with (green in the plot) or without (yellow) the use of ultrasounds.  
Conceptualization, M.L.C. and N.M.; data curation, L.C., M.B., F.C., and G.M.; formal analysis, L.C. and M.B.; project administration, F.C., M.L.C., and N.M.; resources, L.C., M.B., F.C., G.M., M.L.C., and N.M.; supervision, M.L.C. and N.M.; writing--original draft, L.C. and M.B.; writing--review and editing, F.C., M.L.C., and N.M.  
The work was supported by COMPETITIVE--claims of olive oil to improve the market value project (AGER 2 Project, grant no. 2016-0174) and by a grant of Istituto Nutrizionale Carapelli.  
The authors declare no conflict of interest.