Deconstructing extra virgin olive oil through fractionation processes

Arbequina monovarietal extra virgin olive oil (EVOO) was fractionated through a multi-step dry fractionation method. Three of the isolated fractions were selected and analyzed: one being liquid at 4 degrees C, and two being solid at 4 degrees C, and at 12 degrees C. Differential scanning calorimetry (DSC) combined with synchrotron radiation X-ray diffraction (SR-XRD) techniques were employed to monitor the polymorphic crystallization and transformation processes when samples were cooled from the melt to complete crystallization and reheated at a rate of 2 degrees C/min. Fatty acid profiles and alpha-tocopherol contents were also determined for EVOO and associated fractions. Each sample exhibited a different and unique crystallization and polymorphic behavior, and the number of crystal-lizing forms and complexity of transitions increased for solid fractions. In more detail, just two polymorphs (beta'3- 2L and beta'2-2L) were detected in the liquid fraction, whereas the fraction which remained in the solid state at 12 degrees C exhibited six different phases (alpha-2L; beta'3-2L; beta'2-2L; beta'1-2L; beta'2-3L; beta'1-3L). These dissimilarities were strongly correlated with meaningful variations in the fatty acid moieties forming TAG structures and caused large deviations in the crystallization and melting temperatures. As an example, melting temperatures of the liquid and the solid fraction at 12 degrees C were about-3 degrees C and 17 degrees C, respectively. It may be worth exploring the potential of EVOO fractions to be used for improving properties of food stuff, among others. The liquid fraction may be of interest due to its high nutritional value owing to elevated contents in monounsaturated fats and antioxidants, whereas the solid fraction at 12 degrees C may become a good choice to be used as a high-oleic soft fat.

Automated summary

Arbequina monovarietal extra virgin olive oil (EVOO) was studied for its crystallization and polymorphic behavior through fractionation. Different crystallization and polymorphic behaviors were observed for each fraction, with solid fractions exhibiting more complex transitions and a greater number of crystalline forms.