Identification of Adulterants in Extra Virgin Olive Oil Using HS-SPME-GC-MS and Multivariate Data Analysis

Food fraud, such as the adulteration of extra virgin olive oil (EVOO), is found to cause substantial negative impacts on both the economy and the health of consumers. This work was aimed at evaluating 19 EVOO samples commercialized in Foz do Iguaçu, a frontier city located around the triple border of Brazil, Argentina, and Paraguay. To detect the presence of adulteration in EVOO samples, the present study employed gas chromatography coupled to flame ionization detector (GC-FID) and headspace solid phase microextraction with gas chromatography coupled to mass spectrometry (HS-SPME-GC-MS) in order to evaluate fatty acids composition and volatile organic compounds (VOCs), respectively. The quantitative results obtained from the analysis of fatty acids composition showed that 32% of the EVOO samples were adulterated, presumably with soy oil, due to the high levels of linoleic, linolenic, and myristic acids present in them. Principal component analysis (PCA) conducted using the complete chromatographic aroma profiles obtained from the VOCs helped distinguish authentic EVOO samples from adulterated ones and the country of origin of the samples. The following aromatic compounds were first described, as possible adulterant markers: 3,3-dimethylheptanoic acid, propyl pentanoate, methyl cyclohexanecarboxylate, ethyl cyclohexanecarboxylate, 2-phenylethyl acetate, 6,10,14-trimethylpentadecan-2-one, and 1,2-dimethoxy-4-methylbenzene.

Keywords:
fatty acid profile; volatile organic compounds; aroma; adulteration; PCA