Extraction of olive oil assisted by high-frequency ultrasound standing waves

Pablo Juliano; Fabian Bainczyk; Piotr Swiergon; Made Ian Maheswara Supriyatna; Claudia Guillaume; Leandro Ravetti; Pablo Canamasas; Giancarlo Cravotto; Xin-Qing Xu

doi:10.1016/j.ultsonch.2017.02.038

Extraction of olive oil assisted by high-frequency ultrasound standing waves

Ultrason Sonochem. 2017 Sep:38:104-114. doi: 10.1016/j.ultsonch.2017.02.038. Epub 2017 Mar 1.

Authors

Pablo Juliano¹, Fabian Bainczyk², Piotr Swiergon³, Made Ian Maheswara Supriyatna⁴, Claudia Guillaume⁵, Leandro Ravetti⁵, Pablo Canamasas⁵, Giancarlo Cravotto⁶, Xin-Qing Xu³

Affiliations

¹ CSIRO Agriculture and Food, 671 Sneydes Rd, Werribee, VIC 3030, Australia. Electronic address: pablo.juliano@csiro.au.
² CSIRO Agriculture and Food, 671 Sneydes Rd, Werribee, VIC 3030, Australia; University of Mannheim, Paul-Wittsack-Strasse 10, 68163 Mannheim, Germany.
³ CSIRO Agriculture and Food, 671 Sneydes Rd, Werribee, VIC 3030, Australia.
⁴ CSIRO Agriculture and Food, 671 Sneydes Rd, Werribee, VIC 3030, Australia; Wageningen University, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands.
⁵ Boundary Bend Ltd, 151 Broderick Road, Lara, Australia.
⁶ Dip.to di Scienza e Tecnologia del Farmaco, University of Turin, via P. Giuria 9, Turin I-10125, Italy.

PMID: 28633809
DOI: 10.1016/j.ultsonch.2017.02.038

Abstract

High-frequency ultrasound standing waves (megasonics) have been demonstrated to enhance oil separation in the palm oil process at an industrial level. This work investigated the application of megasonics in the olive oil process on laboratory and pilot scale levels. Sound pressure level and cavitational yield distribution were characterised with hydrophones and luminol to determine associated physical and sonochemical effects inside the reactor. The effect of water addition (0%, 15%, and 30%), megasonic power levels (0%, 50%, and 100%), and malaxation time (10min, 30min, and 50min) was evaluated using response surface methodology (RSM) in a 700g batch extraction process. The RSM showed that the effect of the megasonic treatment (585kHz) in the presence of a reflector is more prominent at longer malaxation time (50min) and at higher water addition (30%) levels post-malaxation. Longer megasonic treatment of the malaxed paste (up to 15min; 220kJ/kg) increased oil extractability by up to 3.2%. When treating the malaxed paste with the same specific energy, higher oil extractability was obtained with longer treatments and low megasonic power levels in comparison to higher power levels and shorter times. Megasonic treatment of the paste before malaxation (585kHz, 10min, 146kJ/kg) and no water addition provided an increase in oil extractability of up to 3.8% with respect to the non-sonicated control. A double sonication intervention, before and after malaxation, using low (40kHz) and high (585kHz) frequency, respectively, provided up to 2.4% increase in oil extractability. A megasonic intervention post-malaxation (400 and 600kHz, 57-67min, 18-21kJ/kg) on a pilot scale using early-harvest olive fruits resulted in up to 1.7% extra oil extractability. Oil extracted under a high sonication frequency (free radical production regime) did not impact on olive oil quality parameters at reactor characterisation levels. Megasonic standing wave forces can enhance olive oil separation at various stages of the olive oil extraction process.

Keywords: Extraction; High-frequency sonication; Olive oil; Separation; Ultrasound.