Characterization of extra virgin olive oils derived from the Croatian cultivar Oblica

The objective of the present research work was the characterization of extra-virgin olive oils derived from the main cultivar at the Adriatic coast Oblica by the determination of selected organic parameters as well as of the elemental composition. Twenty elements were quantified by inductively coupled plasma - optical emission spectrometry (ICP-OES) after acidic microwave assisted digestion. In all samples the concentrations of As, Cd, Co, Cr, Mn, Mo, Pb, and V were below the LOD. The mode of production (pressing or centrifugation) is reflected in the contents of Cu, Fe, Ni, and Si. Thus only the contents of Al, Ca, K, Mg, Na, Se, Sn, and Zn ranging from 0.02 - 0.5, 0.8 - 11, 0.1 - 2.5, < LOD - 0.2, 2.7 - 4.2, 0.6 - 2.9, < LOD - 4.8, and 2.5 - 4.0 mu g/g oil, respectively, can be used for characterizing the Oblica variety. The organic quality parameters analyzed were free fatty acids (0.1 to 0.6% oleic acid), peroxide value (2.2 to 4.4 mmol O(2)/kg) and specific absorbances in the UV range (K(232) 0.8 to 1.9; K(270) 0.8 to 1.9; 0.08 to 0.21; and Delta K < 0.003). Practical applications: Oil characterization by organic as well as inorganic parameters is the basis for nutritional and food technological investigations such as adulteration detection and genuineness analysis. Knowing the composition of authentic samples (reference values) is necessary in order to be able to detect differences caused by fraud in products available on the market. Since Croatia is a candidate for entering the European Union the characterization of food stuff coming from this country is of great concern.