An easy and effective molecular approach for varietal traceability in pasta.

Background Pasta is one of the most popular Italian foods in the world. The choice of variety to be used to produce pasta is at the discretion of the producer based on the peculiar characteristics of each cultivar. The quality and the price of each pasta product are strongly related to the used varieties. The availability of analytical approaches for the tracking of specific varieties along the productive chain is becoming increasingly important to authenticate the pasta products and distinguish between fraudulent activities and cross-contaminations during the production process. Methods Twenty-five pasta samples, indicated as composed of a blend of four varieties by the producer, and ten durum wheat varieties were analyzed. In addition, 27 hand-made mixtures were prepared by mixing a blend of the above-mentioned four varieties in equal parts and a growing amount of a fifth contaminant variety. The samples were genotyped using a set of 10 SSR markers. The collected genetic data were used to construct a UPGMA tree and perform a PCoA. The hand-made mixtures were used to calculate the limit of detection (LOD6) and compare the estimated contaminant percentage with the actual one. Results The commercial mixtures presented similar molecular profiles with multiple alleles indicating the use of more than one variety in their production. The alleles of at least two of the four varieties declared by the producer were present, thus indicating that the mixtures were actually composed of these cultivars. However, most of the commercial samples presented also a foreign allele, whose presence was suggested due to a cross-contamination rather than an intentional addition. The LOD6 was assessed to be 5%. Among the used markers, the DuPw205 was shown to be the most accurate in the estimation of contaminant variety percentage. Conclusions We demonstrated the feasibility of the proposed method and its effectiveness in the detection of not declared varieties when these are present in a percentage equal to or higher than 5%.