Inductively Coupled Plasma Application for the Classification of 19 Almond Cultivars Using Inorganic Element Composition

Ten inorganic elements (Ca, Cu, Fe, S, K, P, Na, Mn, Mg, and Zn) have been determined in the kernel of 19 almond cultivars grown in the same field and year, but from different origins, by means of inductively coupled plasma (ICP) after a microwave digestion of the samples. Statistical methods have been applied to a batch of 171 samples to find relations among the cultivars. The F ratios obtained by applying ANOVA analysis are all significant, indicating that a classification of the cultivars using these variables is reasonable to pursue. The cluster analysis and the principal component analysis can distinguish the American cultivars Non Pareil, Wawona, and Texas from the remainder of almonds, most of them from the Mediterranean area, while the Titan cultivar, also an American one, shows a great similarity to Atocha, a Spanish almond. Further, linear discriminant analysis is used to identify the inorganic elements that contribute to a higher degree to find differences between the hypothesized groups of almonds obtained from a principal component analysis and cluster analysis. Keywords: Inductively coupled plasma; microwave digestion; multivariate analysis; almonds