Sviluppo di metodiche di tracciabilità molecolare per l'identificazione di specie, in matrici semplici e complesse, di origine animale e vegetale

Several phenomena related to globalization, such as the emergence of new food products and initiatives to promote local products with the creation of labels of origin, have led to the need to develop new analytical methods to ensure quality and compliance with the legal requirements imposed on food production. The present study dealt with different aspects of food chain traceability by assessing the ability to apply innovative methods to solve real problems. The first chapter deals with the problematic of allergenic matrix detection in food products. For this purpose two molecular methods have been compared, namely PCR and Real-time PCR using specific UPL probes commercially developed by Roche. The results clearly show the advantage in terms of detection sensitivity using the method of Real-time PCR with UPL probes that allowed us to obtain detection limits up to three orders of magnitude lower than the traditional method of PCR. The simplicity of the methodology developed, the relatively low cost and the high sensitivity, in line with regulatory requirements, make this approach a reliable tool for allergen detection in food matrix. In the second part of this work we have investigated the enormous potential of DNA barcoding technique for the identification of animal species. We have developed an APEXmicroarray plateform that is a powerful, economical and rapid instrument for species identification, using data obtained by DNA barcoding. The performances of this innovative plateform have been successfully applied for the identification of five fish species of commercial interest. The last part of this thesis concerned the research and the evaluation in terms of amplificability and informativity of potential candidate genes as universal barcodes for the vegetal kingdom. Gene assessment has been carried out on a collection of plant species belonging to Passiflora genus that possesses noteworthy interests in food field as well as in medical field. Two genes, namely rpoC1 and ncpGS, have been found to be able to discriminate species in Passiflora genus. Using a multilocus approach we have been able to improve the accuracy of the identification and the definition of phylogenetic trees.