Colorimetric characterization and classification of the virgin olive oil from the spanish-moroccan mediterranean area

Abstract

Colour measurements by reflection of 200 virgin olive oil samples from the southern zone of Spain and the northern one of Morocco were made. Acidity measurements of these oils were made as well, and a cluster analysis was employed for their classification. Results show that, generally, Moroccan oils present a hue more greenish (hº average of 87.3º) than the Spanish ones (85.1º), and those are less saturated (C* average of 91.7 and 105.3, respectively). On the other hand, acidity is remarkably different for these two geographic zones, having average values of 0.31 for Spanish oils and 2.87 for Moroccan ones. From these experimental measurements, the cluster analysis shows that it is possible to classify these oils according to their geographic production zones (Spanish-Moroccan area) depending on the acidity or the hue angle.