Multielement Fingerprinting as a Tool in Origin Authentication of PGI Food Products: Tropea Red Onion

Abstract

Tropea red onion ( Allium cepa L. var. Tropea) is among the most highly appreciated Italian products. It is cultivated in specific areas of Calabria and, due to its characteristics, was recently awarded with the protected geographical indications (PGI) certification from the European Union. A reliable classification of onion samples in groups corresponding to "Tropea" and "non-Tropea" categories is now available to the producers. This important goal has been achieved through the evaluation of three supervised chemometric approaches. Onion samples with PGI brand (120) and onion samples not cultivated following the production regulations (80) were digested by a closed-vessel microwave oven system. ICP-MS equipped with a dynamic reaction cell was used to determine the concentrations of 25 elements (Al, Ba, Ca, Cd, Ce, Cr, Dy, Eu, Fe, Ga, Gd, Ho, La, Mg, Mn, Na, Nd, Ni, Pr, Rb, Sm, Sr, Tl, Y, and Zn). The multielement fingerprint was processed using linear discriminant analysis (LDA) (standard and stepwise), soft independent modeling of class analogy (SIMCA), and back-propagation artificial neural network (BP-ANN). The cross-validation procedure has shown good results in terms of the prediction ability for all of the chemometric models: standard LDA, 94.0%; stepwise LDA, 94.5%; SIMCA, 95.5%; and BP-ANN, 91.5%.

Antioxidant activity of phenolic extracts from different cultivars of Italian onion (Allium cepa) and relative human immune cell proliferative induction

“…The first class includes anthocyanins, which impart a red/purple color to some cultivars, and flavonols such as quercetin and its derivatives responsible for the yellow flesh and brown skins of many other cultivars. In Italy, several onion cultivars are farmed although only Tropea Red Onion, that was recently awarded with the protected geographical indication (PGI) certification from the European Union, has been the subject of many scientific investigations (Bonaccorsi et al, 2005;Corea et al, 2005;Dini et al, 2005Dini et al, , 2008aFuria et al, 2011;Gennato et al, 2002). Contrariwise, a unique study (Marinozzi et al, 2014) has dealt with the three Italian onion cultivars (Rossa di Toscana, Borettana di Rovato, and Dorata di Parma) widely farmed in Cannara, a small town in the Umbria region, well known since the ancient time for onion growing, that has developed thanks to the water abundance and the favorable geo-pedological characteristics of the soil.…”

Combination of multi-element and stable isotope analysis improved the traceability of chicken from four provinces of China

“…Multiple elements including trace elements were also analyzed as potential parameters for distinguishing the origin of chicken samples since site-specific features can be provided (Franke et al, 2007;Furia, Naccarat, Sindona, Stabile, & Tagarelli, 2011;Pilgrim et al, 2010;Santato, Bertoldi, Perini, Camin, & Larcher, 2012). Meanwhile, the concentration of multiple elements is an indicator of the elemental composition of feed (Brunner, Katona, Stefánka, & Prohaska, 2010;Pisani, Protano, & Riccobono, 2008).…”

QA: Fraud Control for Foods and Other Biomaterials by Product Fingerprinting

“…The multi-element fingerprint is thus a valuable marker of the geographical origin of food. For instance, the authenticity of Tropea red onion, an onion Italian variety that achieved the PGI certification by the European Union as "Cipolla Rossa di Tropea Calabria" can be proved by means of multi-elemental analysis by ICP-MS and multivariate statistics [6]. All the statistical models applied (LDA, stepwise LDA, SIMCA, ANN), allowed a success rate of prediction >90% for the genuine samples.…”