Combined use of High-Resolution Nuclear Magnetic Resonance (NMR) spectroscopy in solution and multivariate statistical analysis for the geographical differentiation of Italian and Chinese concentrated tomato paste. Particularly the metabolites content of acqueos exctrats of concentrated tomato paste is evaluated. The obtained data are included in a classification statistical model performed on NMR data related to more than 100 double and triple Italian and Chinese concentrated tomato paste samples belonging to two production years (2007 and 2008) representing our database. This latter allows to classify the analyzed sample according to its provenance regardless of the production year and concentration rate.
The methodology allows to monitor different classes of chemical compounds within a single experiment; the whole of these compounds (metabolites) reflects the pedoclimatic conditions in which tomato plant is harvest giving information relating to its provenance. Actually the variation of the metabolites content cannot be attributed neither to tomato ripening stage, nor to the used cultivars, nor to the processing since both in Italy and China, tomatoes with different ripening stages, 15/20 cultivars and the same processing procedures are used. Moreover, the proposed methodology, investigates lyophilized samples; this represents an advantage versus isotopic techniques that monitor isotopes also present in water, which could introduce errors. Finally, the database includes more than 100 Italian and Chinese double and triple concentrated tomato paste samples belonging to two production years.