The present work deals with industrial scale trials aimed to investigate on rheological properties, energy consumption, oil yield and olive oil quality when the calcium carbonate was used during the extraction process. No statistical differences were found in terms of extraction yields. Regarding analytical results of oils, no significant differences were found when comparing oils obtained with or without carbonate and all of them could be classified as "extra virgin olive oil" according to European rules. The use of calcium carbonate does increase the apparent viscosity of the olive paste without, for this, affecting the performance of the machines. The use, as a technological coadjuvant, of calcium carbonate, can bring towards a reduction of the malaxation time. This can have an advantage in terms of the increasing of work capacity of the plant and the reduction of the total energy employed for the extraction process. Published by Elsevier Ltd.