Salt improves physical extraction of olive oil

The use of two concentrations of common salt (0.6 and 1.2%) as coadjuvant for the physical extraction of olive oil has been tested at a laboratory scale and compared with those tests which did not use a coadjuvant or used talc, the only coadjuvant that is allowed according to EC regulations, using the fruits of six different olive varieties (Olea europaea L. cvs. Arbequina, Hojiblanca, Lechin, Manzanilla, Picual, and Verdial). Common salt systematically allowed a higher oil yield than the controlled extraction without coadjuvants, with similar recovery rates to those values obtained when using the more expensive alternative of talc. Physicochemical quality parameters of the virgin olive oils were not significantly affected by the use of this coadjuvant. However, the levels of oil stability, pigment content or intensity of bitterness were slightly increased. Salt addition seems to be a feasible alternative for the improvement of oil extraction. No appreciable advantages were observed when using the higher concentration of salt tested.