ORIGINAL PAPER High Power Ultrasound: Impact on Olive Paste Temperature, Malaxation Time, Extraction Efficiency, and Characteristics of Extra Virgin Olive Oil Basheer M. Iqdiam 1 & Hussein Mostafa 1 & Renee Goodrich-Schneider 1 & George L. Baker 1 & Bruce Welt 2 & Maurice R. Marshall 1,3 Received: 17 August 2017 /Accepted: 20 November 2017 # Springer Science+Business Media, LLC, part of Springer Nature 2017 Abstract High power ultrasound (HPU) provides rapid heating of olive paste and disrupts cell walls, helping small oil droplets exit tissue and coalesce. This has been shown to improve oil yield and reduce malaxation time without affecting oil quality. Indirect and direct HPU at different treatment times were examined on Arbequina and Frantoio olive pastes. Olive pastes were mixed at four different malaxation times to evaluate extraction efficiency. Additionally, oil yield and different quality parameters were ob- served. HPU increased olive paste temperature from 20 ± 0.5 to 25.5 °C, achieving the optimum kneading temperature of 29 ± 1 °C in less mixing time. HPU significantly (P < 0.05) improved oil yield by 1% for both varieties. There were no significant differences (P > 0.05) in oil yield between 35 and 45 min malaxation time, suggesting the possibility to reduce malaxation by 10 min with HPU. No significant differences (P > 0.05) were observed in any quality parameters observed, except peroxide value, which increased slightly. Significant increases (P < 0.05) in total tocopherol and pigments with increasing HPU treatment time occurred, while a decrease in total polyphenol and oxidative stability index resulted after 8 min treatment. HPU influenced L, a, and b values causing the oil to become darker. Sensory results showed no differences between commercially available and HPU-treated samples. These results suggest the possibility of using HPU treatment to increase oil extraction capacity and yield without loss of product quality. Keywords Extra virgin olive oil . High power ultrasound . Malaxation . Extraction efficiency . Oil quality Introduction Extra virgin olive oil (EVOO) is distinguished by its high content of nutritional and antioxidant compounds compared to other vegetable oils (Cicerale et al. 2009; Kalogeropoulos and Tsimidou 2014; Konstantinidou and Fito 2009; Pérez- Martínez et al. 2011; Salvador et al. 1999). These nutritive and therapeutic benefits have resulted in an increase in consumption of Bextra virgin category^ oils (Salvador et al. 2003). The antioxidant content and the characteristic sensory attributes of olive oil depend on several factors such as culti- var, maturity index, extraction process, and storage conditions (Ayton et al. 2012; Inglese et al. 2011; Tapp et al. 2003; Uceda et al. 2006). EVOO is the expressed juice from olive fruits (Olea europaea L.), ideally picked and handled through me- chanical or physical process (Angerosa 2002; Clodoveo 2012; Gomez-Rico et al. 2006; Puértolas and Martínez De Marañón 2015; Sacchi et al. 1998). The extraction process involves crushing olive fruits, malaxation of olive paste, and solid– liquid separation by centrifugation (Bejaoui et al. 2016; Clodoveo et al. 2014; Uceda et al. 2006). In fact, one of the industrial handicaps facing olive oil production is the low efficiency of the current extraction process (Aguilera et al. 2010; Clodoveo and Hachicha Hbaieb 2013; Moya et al. 2010). Often, the hammer does not break all the cells during crushing, which leaves some oil droplets remaining in the plant tissue (Chiacchierini et al. 2007). In addition, using me- tallic olive mills cause a violent milling process which * Maurice R. Marshall martym@ufl.edu 1 Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA 2 Agricultural & Biological Engineering Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA 3 Food Science and Human Nutrition Department, Food & Environmental Toxicology Laboratory, University of Florida, 1642 SW 23rd Drive, Gainesville, FL 32611-0720, USA Food and Bioprocess Technology https://doi.org/10.1007/s11947-017-2035-8