Characterization of arabica and robusta roasted coffee varieties and mixture resolution according to their metal content

The metal content of roasted coffee samples belonging to the arabica and robusta varieties and coffee blends has been analysed. Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr, Zn have been determined by inductively coupled plasma atomic emission spectrometry. Principal component and cluster analysis have been applied to characterize the coffee varieties. P, Mn and Cu have been found to be the most discriminating variables. Partial least squares regression was applied to determine the relative content of each variety in the coffee blends. This method has been applied to determine the percentage of the robusta variety in some commercial roasted coffee samples.