Beyond the traditional virgin olive oil extraction systems: Searching innovative and sustainable plant engineering solutions

The entire virgin olive oil (VOO) process has changed very little over the last 20 years. One of the essential challenges of VOO industrial plant manufacturing is to design and build advanced machines in order to improve the working capacity of the industrial plants and create more sustainable engineering solutions. Ultrasound (US) and microwave (MW) are emerging technologies that have already found application in the food industry. Yet, application in the VOO sector has been scarcely investigated. In order to ascertain if the mentioned emerging technologies are able to increase the environmental sustainability improving VOO extraction yields, two different treatments (US and MW) of olive paste were adopted in the VOO extraction process on a pilot scale plant. In these experimental conditions, the main parameters legally established (acidity, peroxide value, and specific extinction coefficients (K-232 and K-270)) to evaluate VOO quality were not affected by the US and MW treatments. Moreover US and MW processes reduced significantly the length of the malaxation and improved the extraction yield as compared with the control when the oils were extracted from the paste without malaxation. Results also prove that US technology was more sustainable than MW which appears as an energy consuming method in a pilot scale plant. Therefore the industrial application of these technologies could represent the first step toward the development of continuous new devices. (C) 2013 Elsevier Ltd. All rights reserved.