A Method to Check and Discover Adulteration of Nebbiolo-Based Monovarietal Musts: Detection of Barbera and Dolcetto cv via SSR Analysis Coupled with Lab-On-Chip® Microcapillary Electrophoresis

The process of wine traceability/authentication is a key target for Italy, the world's first largest wine producer (around 4. 6 million tons in 2010 according to FAOSTAT). Several European countries developed appellation systems, with their own unique labels and seals, trying to fight label fraud that misrepresented the true origins of the wine. Advancements on this topic were provided by Council Regulation (EC) No. 479/2008 on the common organisation of the market in wine. As reported by experts, it is suspected that as much as 5 % of the wine sold in secondary markets worldwide could be counterfeit. Despite the high number of traceability methods, commonly based on the use of time consuming and expensive techniques (SNIF-NMR and stable isotope-ratio mass spectrometry), few applications report the use of polymerase chain reaction directly in musts or in bottled wine. Information on genetic polymorphism given by simple sequence repeats (SSR; microsatellite markers) proved helpful when applied to grape and musts analysis. The limited quantity of amplifiable grape genomic DNA in wine represents the main issue for the application of such analytical approach. Musts are the first intermediate product to be checked, in order to exclude the unintentional or fraudulent contamination with foreign grape varieties. The aims of this work are (1) the selection of performing SSR markers able to discriminate 'Barbera' and 'Dolcetto' from 'Nebbiolo' and (2) the hyphenated use of capillary micro-electrophoresis (lab-on-chip technology) for polymorphisms detection, to highlight the presence of foreign grape in 'Nebbiolo' musts produced in purity, as required by the designation disciplinary. Finally, we suggest using this approach by exploiting VVS2 marker in order to detect Barbera and Dolcetto grapes in Nebbiolo musts, waiting for more robust and powerful method to extract and amplify specific DNA from bottled wine.