**4. Conclusion**

The new treatment ST not only maintains the advantages of the SES with regard to the concentration of oil in the final solid and phase separation, but also diminishes the oxidation and significantly improves the concentration of the most interesting components of the minor fractions of POO. Thus, the application of ST enhances the functional properties of this new POO, increasing the oil extraction yield and the total recovery of bioactive compounds from the refining process.

The steam treatment offers not only serious advantages in terms of the oil but also in terms of the total recovery of alperujo as described above. The application of ST to treat olive oil wastes allows the phase separation and the concentration of interesting compounds and components in each phase. In the liquid phase, bioactive compounds like phenols and oligosaccharides are solubilised and are easy to extract. In the solid fraction, the oil and cellulose are concentrated. After the oil extraction, the solid has a low content of phytotoxics that are in the liquid phase, and therefore, it is susceptible for bio-treatment for the total utilisation of this fraction.
