Traceability of “Tuscan PGI” Extra Virgin Olive Oils by 1H NMR Metabolic Profiles Collection and Analysis

Abstract

According to Coldiretti, Italy still continues to hold the European Quality record in extra virgin olive oils with origin designation and protected geographical indication (PDO and PGI). To date, 46 Italian brands are recognized by the European Union: 42 PDO and 4 PGI (Tuscan PGI, Calabria PGI; Tuscia PGI and PGI Sicily). Specific regulations, introduced for these quality marks, include the designation of both the geographical areas and the plant varieties contributing to the composition of the olive oil. However, the PDO and PGI assessment procedures are currently based essentially on farmer declarations. Tuscan PGI extra virgin olive oil is one of the best known Italian trademarks around the world. Tuscan PGI varietal platform is rather wide including 31 specific olive cultivars which should account for at least 95% of the product. On the other hand, while the characteristics of other popular Italian extra virgin olive oils (EVOOs) cultivars from specific geographical areas have been extensively studied (such as those of Coratina based blends from Apulia), little is still known about Tuscan PGI EVOO constituents. In this work, we performed, for the first time, a large-scale analysis of Tuscan PGI monocultivar olive oils by 1H NMR spectroscopy and multivariate statistical analyses (MVA). After genetic characterization of 217 leaf samples from 24 selected geographical areas, distributed all over the Tuscany, a number of 202 micro-milled oil samples including 10 PGI cultivars, was studied. The results of the present work confirmed the need of monocultivar genetically certified EVOO samples for the construction of 1H-NMR-metabolic profiles databases suitable for cultivar and/or geographical origin assessment. Such specific PGI EVOOs databases could be profitably used to justify the high added value of the product and the sustainability of the related supply chain.

1H-NMR Metabolite Fingerprinting Analysis Reveals a Disease Biomarker and a Field Treatment Response in Xylella fastidiosa subsp. pauca-Infected Olive Trees

“…In this work, the PLS-DA analysis was also applied with the aim to justify the number of components used in OPLS-DA model [57]. The OPLS-DA analysis is a modification of the usual PLS-DA method which filters out variation not directly related to the discriminating response and brings out models of clearer interpretation, as reported in several studies [58,59]. The further refinement provide by the OPLS-DA in MVA lies in the capability to divide the portion of the variance helpful for predictive purposes from the not predictive variance (which is made orthogonal) [60].…”

Near UV-Vis and NMR Spectroscopic Methods for Rapid Screening of Antioxidant Molecules in Extra-Virgin Olive Oil

“…A 1 H NMR spectral analysis was indeed applied as the target analysis for the detection and quantification of phenolic compounds, diacylglycerols and for fatty acid composition determinations [ 9 , 34 , 36 , 37 ]. It was also employed in metabolic profiling and fingerprinting in order to detect adulterations [ 38 ], to assess geographical origins [ 35 , 39 , 40 ] or to define the employed harvest method [ 41 ]. 13 C NMR spectroscopy was used mainly to provide valuable information about the acyl distribution and the acyl positional distribution of glycerol tri-esters in oils [ 40 ].…”

Extra-Virgin Olive Oils from Nine Italian Regions: An 1H NMR-Chemometric Characterization

“…Furthermore, it is well known that NMR experiments are quickly performed and require neither selective extraction nor derivatization, thus reducing the experimental error and the analysis time [7]. In recent studies, the NMR analytical chemometric approach has been interfaced with the aim to build up statistical models able to characterize olive oils from Liguria [6], Apulia [8,9], Tuscany [10] and Sicily [11,12].…”