The utilization of solid carbon dioxide in the extraction of extra-virgin olive oil.

The impact of the addition of solid CO2 on olive oil (EVOO/VOO) production in terms of extraction yield and chemical quality was studied at pilot scale in an industrial oil-press in two different crop seasons. The addition of CO2,s to the fruits induces the intracellular water freezing and the consequent laceration of cellular membranes could induce the diffusion of many cellular compounds. In the experimental conditions adopted, the addition of the cryogen to the olives during pre-milling phase greatly increased the extraction yield (ranging from ≅ 1 to ≅ 21 %), with respect to the related control. Furthermore, the use of solid CO2 had no negative effects on chemical composition of the olive oil, maintaining the highest quality according to EU legal standards showed by control. Therefore, the utilization of solid CO2 as cryogen could be an appropriate technology to improve olive oil yield and quality and increase its shelf-life.