Chapter 18 - Classification of Sicilian Olive Oils According to Heavy Metal and Selenium Levels using Canonical Discriminant Analysis (CDA)

Abstract

The presence of metals in vegetable oils depends on many factors: they might originate from the soil, fertilizers, and presence of industry or highways near the plantations, and be incorporated in the oil. The metals may also be introduced during the production process or by contamination from the metal processing equipment and thus be suspended in the oil. Taking into account the metabolic role of some metals and the large use of olive oils, it is of great concern to evaluate the presence of Cd (II), Cu (II), Pb (II), Zn (II) and Se (IV) in olive oils produced in Sicily in two different crop years (2000 and 2001). Stripping chronopotentiometry was used as a rapid, sensitive, and reproducible method to determine metal trace levels in acid extracts of olive oils. Recently the classification of olive oils based on the chemical composition has become an important challenge for researchers; in this regard it has been shown that the concentration of an inorganic element such as selenium is characteristic of the cultivar. This chapter aims (1) to summarize results from previous studies reporting the concentrations of some heavy metals and selenium in Sicilian virgin olive oils from three different varieties; (2) to use a statistical tool as canonical discriminant analysis (CDA) to classify virgin olive oils from different cultivars according to their heavy metal and selenium content.