Sequential (step-by-step) detection, identification and quantitation of extra virgin olive oil adulteration by chemometric treatment of chromatographic profiles

An analytical method for the sequential detection, identification and quantitation of extra virgin olive oil adulteration with four edible vegetable oils — sunflower, corn, peanut and coconut oils — is proposed. The only data required for this method are the results obtained from an analysis of the lipid fraction by gas chromatography–mass spectrometry. A total number of 566 samples (pure oils and samples of adulterated olive oil) were used to develop the chemometric models, which were designed to accomplish, step-by-step, the three aims of the method: to detect whether an olive oil sample is adulterated, to identify the type of adulterant used in the fraud, and to determine how much aldulterant is in the sample. Qualitative analysis was carried out via two chemometric approaches — soft independent modelling of class analogy (SIMCA) and K nearest neighbours (KNN) — both approaches exhibited prediction abilities that were always higher than 91% for adulterant detection and 88% for type of adulterant identification. Quantitative analysis was based on partial least squares regression (PLSR), which yielded R2 values of >0.90 for calibration and validation sets and thus made it possible to determine adulteration with excellent precision according to the Shenk criteria.

[1]  G. Downey,et al.  Detecting and quantifying sunflower oil adulteration in extra virgin olive oils from the eastern mediterranean by visible and near-infrared spectroscopy. , 2002, Journal of agricultural and food chemistry.

[2]  Yukihiro Ozaki,et al.  The Detection and Quantification of Adulteration in Olive Oil by Near-Infrared Spectroscopy and Chemometrics , 2004, Analytical sciences : the international journal of the Japan Society for Analytical Chemistry.

[3]  J. Manson,et al.  Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study , 1998, BMJ.

[4]  Howard Mark,et al.  Principles and Practice of Spectroscopic Calibration , 1991 .

[5]  José Luis Pérez Pavón,et al.  Detection of adulterants in olive oil by headspace–mass spectrometry , 2002 .

[6]  M. Valcárcel,et al.  Direct olive oil authentication: detection of adulteration of olive oil with hazelnut oil by direct coupling of headspace and mass spectrometry, and multivariate regression techniques. , 2005, Journal of chromatography. A.

[7]  N. Andrikopoulos,et al.  Squalene in oils and fats from domestic and commercial fryings of potatoes , 2004, International journal of food sciences and nutrition.

[8]  R. Aparicio,et al.  Detection of hazelnut oil in virgin olive oil by a spectrofluorimetric method , 2004 .

[9]  Maria Luisa Ruiz del Castillo,et al.  Detection of the adulteration of olive oils by solid phase microextraction and multidimensional gas chromatography , 2006 .

[10]  A. Antonopoulos,et al.  Detection of olive oil adulteration using principal component analysis applied on total and regio FA content , 2003 .

[11]  G. P. Blanch,et al.  Comparison of different methods for the evaluation of the authenticity of olive oil and hazelnut oil , 1998 .

[12]  G. P. Blanch,et al.  Study of the adulteration of olive oil with hazelnut oil by on-line coupled high performance liquid chromatographic and gas chromatographic analysis of filbertone. , 2006 .

[13]  J. Gómez-Ariza,et al.  Comparative study of electrospray and photospray ionization sources coupled to quadrupole time-of-flight mass spectrometer for olive oil authentication. , 2006, Talanta.

[14]  Ricard Boqué,et al.  Rapid detection of olive–pomace oil adulteration in extra virgin olive oils from the protected denomination of origin “Siurana” using excitation–emission fluorescence spectroscopy and three-way methods of analysis , 2005 .

[15]  Jesús Simal-Gándara,et al.  Control of contamination of olive oil by sunflower seed oil in bottling plants by GC-MS of fatty acid methyl esters , 2003 .

[16]  Michael Komaitis,et al.  Effectiveness of determinations of fatty acids and triglycerides for the detection of adulteration of olive oils with vegetable oils , 2004 .

[17]  George A. Mousdis,et al.  Synchronous fluorescence spectroscopy for quantitative determination of virgin olive oil adulteration with sunflower oil , 2006, Analytical and bioanalytical chemistry.

[18]  Royston Goodacre,et al.  Rapid quantitative assessment of the adulteration of virgin olive oils with hazelnut oils using Raman spectroscopy and chemometrics. , 2003, Journal of agricultural and food chemistry.

[19]  M. Eberlin,et al.  Characterization of vegetable oils by electrospray ionization mass spectrometry fingerprinting: classification, quality, adulteration, and aging. , 2005, Analytical chemistry.

[20]  N. Vlachos,et al.  Applications of Fourier transform-infrared spectroscopy to edible oils. , 2006, Analytica chimica acta.

[21]  Apostolos Spyros,et al.  Detection of extra virgin olive oil adulteration with lampante olive oil and refined olive oil using nuclear magnetic resonance spectroscopy and multivariate statistical analysis. , 2005, Journal of agricultural and food chemistry.

[22]  D. L. García-González,et al.  Using 1H and 13C NMR techniques and artificial neural networks to detect the adulteration of olive oil with hazelnut oil , 2004 .

[23]  Y Vander Heyden,et al.  Gas-chromatographic fatty-acid fingerprints and partial least squares modeling as a basis for the simultaneous determination of edible oil mixtures. , 2005, Talanta.

[24]  D. Kell,et al.  Metabolic profiling using direct infusion electrospray ionisation mass spectrometry for the characterisation of olive oils. , 2002, The Analyst.

[25]  J. Gómez-Ariza,et al.  Use of flow injection atmospheric pressure photoionization quadrupole time-of-flight mass spectrometry for fast olive oil fingerprinting. , 2006, Rapid communications in mass spectrometry : RCM.