A revised method for determination of fatty acid ethyl esters (FAEEs) in virgin olive oils

The analytical evaluation of the content of FAEEs is one of the quality parameters that permits to define the quality grade of a virgin olive oil and to possibly detect fraudulent mixtures of extra virgin olive oils with lower quality oils whether they are virgin, lampante or not allowed (some kinds of soft-deodorized oils with high level of FAEEs).

 

The official protocol for the FAEEs determination (defined by EU Reg. 61/2011) suffers from some limitations in terms of required amount of solvents (≈ 350 mL) and time needed for the preparative phase (≈ 4 hours) that is necessary to isolate these compounds and that is carried out using traditional liquid chromatography.

 

One of the objectives of the OLEUM project is to address these problems proposing, at least, one revised quicker and more sustainable full validated method for the FAEEs determination.

 

In particular, the UNIBO team developed a revised method based on the use of an HPLC-UV-Vis and a GC-FID with PTV injector, revising the preparative phase and changing the GC injector required by the official method (the on-column injector is, at present, not widespread) with a PTV one. The revised protocol allows to carry out the preparative phase in less time (≈ 40 min per analysis once set the HPLC conditions) and with a less amount of solvents (≈ 40 mL) than the official one.

 

Inter-lab validation of this method, involving several laboratories, has just started in order to confirm and strengthen the reliability and good performances of the approach presented herein, in view of its proposal to normative bodies for a possible adoption.

 

The pre-trial are in course and 4 samples, together with the Standard Operating Procedures, have been sent to the participants. The trial proper will start after and it will be required to analyze 11 samples.

 

OLEUM is organizing a training workshop focused on the two analytical approaches studied in the project on the 24th of October 2019 at the Instituto de la Grasa (Seville, Spain) after the Euro Fed Lipid congress.

 

If you are interested in participating in the trial-proper or receiving more information about inter-lab validation contact us at distal.oleum@unibo.it.