β-Carotene, squalene and waxes determined by chromatographic method in picual extra virgin olive oil obtained by a new cold extraction system

Various chromatographic techniques were used to identify the β-carotene, squalene and diverse waxes present in extra virgin olive oil obtained by a new cold extraction system. To determine the wax content, solid-phase extraction on a silica-gel column was used and the fraction was analyzed by capillary gas chromatography. The other compounds present in the non-saponifiable olive oil fraction, i.e. squalene and β-carotene, were analyzed by gas chromatography and reversed-phase high-performance liquid chromatography, respectively. An internal standard was used for the waxes, and the squalene and β-carotene were quantified by means of external standard calibration with reference substances. The analytical parameters recorded recovery assays of over 97% and the satisfactory precision achieved (with RSD values below 8%), the good linearity (r > 0.999), good sensitivity and appropriate limits of detection and quantification, all show that the techniques used are satisfactory for measuring these compounds in extra virgin olive oil. The results obtained indicate that the oils analyzed, obtained by a new cold extraction system, present a higher concentration of components directly associated with the desirable characteristics of extra virgin olive oils.