Chemometric authentification of moroccan picholine virgin olive oil by automatic classification based on the composition of fatty acids and sterols

The traceability of the samples is a recommended procedure to ensure the authenticity of virgin olive oil (voo). the automatic classification is gaining more interest among growers and researchers in the field of olive cultivation,to manage the voo quality control. the first objective of this work is to characterize,in terms of fatty acids and sterols,virgin olive oil from the meknes tafilalt area in morocco since there is a paucity of research on such a land product as mediterranean food presenting nutritive and therapeutic values. the second objective is to detect minimal gas chromatographic differences between samples coming from the same cultivar (moroccan picholine) and the same geographical area (meknes tafilalt). the third objective is to approach the effectiveness and efficiency of the coupling between the gas chromatography on the one hand and on the other chemometric treatment. so,using the principal components analysis (pca),k-means and hierarchical ascendant clustering (hac) methods,the present work is devoted to the characterisation and the authentification based on the composition of the moroccan picholine voo variety in terms of fatty acids and sterols. fatty acids are determined by gas chromatography (gc) after having transformed them to their corresponding metylic esters. the fact of not observing enough aberrant points confirms that the samples have similar varietal and regional origins. the pca has allowed us to reduce a large number of variables (17 variables) to 7 new ones,respecting the minimization of the information loss. the results of the application of k-means and hac on the voo samples have allowed detecting correlations between them. the results also showed that there is little variability in the content of fatty acids and sterols in the voo produced in the moroccan meknes tafilalt area.