Nuclear magnetic resonance analysis of water soluble metabolites allows the geographic discrimination of pistachios (Pistacia vera)

Aqueous extracts of roasted pistachio (Pistacia vera) from different geographic origin were analyzed by H-1 nuclear magnetic resonance (NMR) spectroscopy. Forty-eight water-soluble metabolites, classified in organic acids, amino acids, carbohydrates and miscellaneous metabolites, were identified by means of 1D and 2D NMR experiments, and twenty-eight of them were quantified. The different metabolite contents highlighted that pistachios from different regions have peculiar metabolic features that could be employed for quality control and to improve the requisites for protected or certified designation of origin regulations. For these purposes, multivariate statistic analysis (PCA and PLS-DA) was applied to the obtained metabolite profiles in order to assess the geographic origin of nuts from Aleppo (Syria), Sanliurfa (Turkey), Rafsanjan (Iran) and Bronte (Italy), and spontaneous clustering was observed. (C) 2014 Elsevier Ltd. All rights reserved.