Improved extraction of virgin olive oil using calcium carbonate as coadjuvant extractant

Abstract

Olive oil is gaining a growing interest because of its beneficial effects on human health and hence olive oil production is spreading worldwide. As a result, technical improvements in the olive oil extraction process are continuously under study. In this sense, this work deals with the effect of micronized calcium carbonate, a new technological coadjuvant, on the physical extraction of virgin olive oil. The assays were performed with three olive ( Olea europaea L.) varieties, Picual, Hojiblanca and Arbequina, according to different experimental designs. The results were compared with those obtained using micronized talc, a coadjuvant authorized by European Union regulations. The use as a technological coadjuvant of calcium carbonate, E170 food additive, produced an increase of olive oil extraction yield up to 24% when the mixing temperature was maintained at 30 °C for 55 min. Moreover, micronized carbonate allows a lower temperature to be used without extraction decrease, resulting in higher quality olive oil. Concerning analytical determinations 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 norms. Finally, in comparison to talc use, no statistical differences were found in terms of extraction yields.