Elemental fingerprint of wines from the protected designation of origin Valencia

Abstract

Inductively coupled plasma optical emission (ICP-OES), in combination with different chemometric approaches, has been used to verify the origin of different red wine samples from Utiel-Requena, Jumilla, Yecla and Valencia protected designation of origin (PDO). The ability of multivariate analysis methods, such as hierarchical cluster analysis (HCA), principal component analysis (PCA), classification and regression trees (CARTs) and discriminant analysis (DA), to achieve wine classification from their elemental contents has been investigated. The calculations were performed using 38 variables (contents of Al, Ba, Be, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Gd, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Sc, Se, Sm, Sr, Tb, Ti, Tm, V, Y, Yb and Zn, at mg l −1 level, determined by ICP-OES). Results of HCA and PCA clearly show that Utiel-Requena and Jumilla red wines are very easy to discriminate from the wines of the other PDO in their vicinity. However, wines from Valencia and Yecla PDO cannot be discriminated, based on the aforementioned procedures. Using the CART method, wines from Utiel-Requena and Jumilla can also be easily authenticated, by using only the concentration of Li and Mg, respectively. Wine samples from Valencia PDO sub-regions can be also discriminated with a quite acceptable re-substitution rate. On the other hand, discrimination analysis allows the separation of the entire studied PDO samples, obtaining accuracy results by the re-substitution method of 100%.