Shelf life of extra virgin olive oil manufactured with combined microwaves and megasonic waves at industrial scale

Previous research has demonstrated that the innovative application of combined microwaves and megasonic waves for preconditioning olive paste enabled olive oil production in continuous mode, while delivering higher olive oil yields. The present work further examines the impact of these technologies on the chemical and sensory stability of the oils obtained in previous studies, with reference to international extra virgin olive oil standards. Olive oil samples obtained after traditional malaxation (Control), microwave conditioning (MW), traditional malaxation assisted with megasonics (MS), and the combination of both microwave conditioning followed by megasonics (MW + MS) in a commercial olive oil plant at 350 kg/h, were characterised and evaluated across 1 year at 3-month intervals. All oil samples evaluated met the international extra virgin olive oil standard parameters across the shelf life study. Ethyl esters and waxes increased uniformly across storage indicating no effect of MW or MS on fermentation processes during conditioning. The application of these technologies enhanced the phenolic content in the oils across one-year, with fluctuations among technologies, in comparison to the traditional control process (Control < MW ≈ MS ≈ MW + MS). Overall, this study demonstrates that both MW and MS conditioning technologies and their combination, applied industrially, can create higher quality extra virgin olive oils across storage.