Chromatographic and chemiometric methods for the authentication of olive oil geographical origin

In recent years, the issues of food quality and safety have received a special attention both from the producers and the consumers, in particular the geographical origin is gaining importance as guarantee of quality. On 2009 the European Union (EU) Member States agreed to require origin labeling for virgin and extra virgin olive oils (EC Regulation 182/2009) to defend consumers need about true characteristics and origin. This regulation, together with the well established laws regarding denominations and protected indications of origin (POD PGI and STG), has led to a new olive oil market where geographic origin labels are a big market competitive advantage. To enforce these laws, a measure of the authenticity of samples must be made, most often in the form of proving the presence/absence of adulterants, or verifying geographical or cultivar origin by comparison with known and reliable samples. Many analytical methods (NMR; DNA fingerprint, isotopic ratio, elemental analysis etc) have been employed in the last decades in order to verify the real compliance to the geographical origin declared in the label. Among them, chromatographic techniques are the most utilized for their widespread availability, low cost and reliability, and their data have been successfully used for olive oil traceability models building. These methods often include the use of multivariate statistical techniques such as principal components analysis, linear discriminant analysis, canonical variance analysis and partial least squares regression. In view of the growing interest in this topic, this paper reviews the literature of the application of unsupervised/supervised chemometric methods on chromatographic data for the characterization and authentication of the geographical origin of olive oil.