Combining high power ultrasound pre-treatment with malaxation oxygen control to improve quantity and quality of extra virgin olive oil

The objective of this study was to evaluate high power ultrasound (HPU) treatment before malaxation and control of oxygen during malaxation on extraction efficiency and quality of extra virgin olive oil (EVOO). HPU treatment (150 W and 20 kHz, 13.5 kJ kg−1) was followed by controlling headspace oxygen concentrations (2%, 5%, 10%, and 21% (control)) during malaxation. Oil yield and various oxidative quality parameters were evaluated. The results showed that HPU treatment significantly (p < 0.05) increased oil yield and oil extractability. Significant differences (p < 0.05) between the treatment oxygen concentrations and control were found for the quality parameters measured. Oxygen concentration of 5% in the malaxation headspace appears to be the best balance between oil extraction and quality. Combining these technologies presented potential advantages for EVOO production.