Control of contamination of olive oil by sunflower seed oil in bottling plants by GC-MS of fatty acid methyl esters

This paper describes a quality control method for the detection of contamination of olive oil by seedoil, such as may occur as the result of carryover in bottling lines, with the aim of diagnosing if cross-contamination has occurred and by how much. The method is based on gas chromatography of the methyl esters of the oil components, with detection by mass spectrometry (GC-MSD). In the example presented (contamination by sunflower seed oil), it was identified the optimal discriminatory parameter, which was the ratio between the peak areas of the oleic and linoleic derivatives in chromatograms obtained using full-scan MS between 35 and 350 amu; this ratio would allow diagnosis of contamination of olive oil by sunflower seed oil at least at the 1% level with >95% certainty in bottling plants. It is important that each bottling plant establish its own reference sample collection and identify its optimal discriminant parameters following the proposed procedures.