Chemical composition of virgin olive oils according to the ripening in olives.

The aim of this study was the classification of olive oil according to the stage of ripeness of the olives used for its manufacture. A discriminant analysis was applied taking as dependent variables the fatty acids, triglycerides and sterols profile. The evolution of parameters of quality of the oils during ripening of the fruit has also been studied in three successive crops. The results of the classification shows that 88.5% of selected original grouped cases are correctly classified (85.7% green, 80% spotted and 78.9% ripe) and furthermore the validation classified the 69.6% of the unselected original cases. The most discriminating variables have been: avenasterol, linolenic acid, β-sitosterol and gadoleico. Fig. 1 shows graphically the values of the canonical discriminant functions and the centroids of the intervals of three or the maturity index.