Alkyl esters - a new parameter for the assessment of extra virgin olive oil
By Nadja Liebmann and Dr. Torben Küchler, Eurofins Analytik GmbH, Germany
From April 1st, a new parameter for the assessment of extra virgin olive oil was established in the European Union in Regulation (EEC) 2568/91.
The content of alkyl esters, namely fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE), are regulated. There is a legal limit of 75 mg/kg for the sum of FAME and FAEE, and 150 mg/kg for the sum of FAME and FAEE, if the ratio of FAEE/FAME is below 1.5.
Methyl and ethyl esters of fatty acids are useful indicators for determining the quality of olives and the oil produced from them as they are direct indicators of degradation. Several scientific studies have shown that oil from olives with minor damages contains FAME and FAEE. Oil from damaged olives, which have been mildly deodorised to remove sensory defects can be detected by the presence of the alkyl esters.
Eurofins Analytik GmbH has been able to determine the alkyl esters in olive oil since the end of 2009 and has experience in the procedure for the analysis and assessment of the results. Additionally, storage trials were carried out to verify that alkyl esters are not formed under different storage conditions. Until now, no increase of the alkyl esters has been found in bottled extra virgin olive oils during storage at room temperature. Results of more than 100 extra virgin olive oils from the German and Italian market showed that most of the oils comply with these limits, but several were very close to the legal limits mentioned above.
The analysis of alkyl esters is recommended for extra virgin olive oil in order to derive reliable analytical information on the quality.
Contact: NadjaLiebmann@eurofins.de