Pasta, the Italian product par excellence, is made of pure durum wheat. The use of Triticum durum derived semolina is in fact mandatory for Italian pasta, in which Triticum aestivum species is considered a contamination that must not exceed the 3% maximum level. Over the last 50 years, various electrophoretic, chemical, and immuno-chemical methods have been proposed aimed to track the possible presence of common wheat in semolina and pasta. More recently, a new generation of methods, based on DNA (DeoxyriboNucleic Acid) analysis, has been developed to this aim. Species traceability can be now enforced by a new technology, namely digital Polymerase Chain Reaction (dPCR) which quantify the number of target sequence present in a sample, using limiting dilutions, PCR, and Poisson statistics. In our work we have developed a duplex chip digital PCR (cdPCR) assay able to quantify common wheat presence along pasta production chain, from raw materials to final products. The assay was verified on reference samples at known level of common wheat contamination and applied to commercial pastas sampled in the Italian market.

Several food products, made from hulled wheats, are now offered by the market, ranging from grains and pasta to flour and bakery products. The possibility of verifying the authenticity of wheat species used at any point in the production chain is relevant, in defense of both producers and consumers. A chip digital PCR assay has been developed to detect and quantify percentages of hulless (i.e., common and durum wheat) and hulled (i.e., einkorn, emmer and spelt) wheats in grains, flours and food products. The assay has been designed on a polymorphism in the miRNA172 target site of the AP2-5 transcription factor localized on chromosome 5A and involved in wheat spike morphogenesis and grain threshability. The assay has been evaluated even in a real-time PCR system to assess its applicability and to compare the analytical costs between dPCR and real-time PCR approaches.

Food safety, quality, and traceability have become increasingly important in the agrifood industry in recent years, necessitating the use of reliable and rigorous analytical tools to ensure agrifood surveillance. This work focuses on the development and application of a new molecular approach to verify the authenticity of a specific variety of Triticum turgidum ssp. turanicum, commonly known as Khorasan wheat, which is commercially sold under the KAMUT^® trademark. A method based on duplex digital PCR was developed to identify and quantify T. turanicum variety QK-77 used in KAMUT^® brand products. The assay was validated on pure QK-77 variety alone and mixed with other varieties and on other cereal species. The developed PCR-based assay, tested using two digital PCR platforms (cdPCR and pdPCR), has high sensitivity and accuracy and can be applied to quantify the QK-77 variety in commercial grain lots and processed foods.