Wine Authenticity Throughout the Wine-Chain: Exploring the Potential of HRM-SNP Assays in Varietal Discrimination and Quantification in Wine Blends.

Varietal identity is an essential part of wine authentication and should be assessed throughout the winemaking process. DNA markers such SSRs have been applied for grapevine identification but can underperform in wine sample analysis. SNP markers combined with High Resolution Melting represent an alternative approach wine analysis. Our aim was to develop HRM assays targeting similar to 100 bp fragments, applicable for varietal discrimination in must and wine, and evaluate their potential as quantification tool in wine blends. Varieties Cabernet Sauvignon, Donzelinho Tinto, Touriga Franca, Touriga Nacional and Rufete were used. Four SNP markers were selected for HRM assays development. Three assays discriminated the varieties using must samples. Using wine DNA, the results varied but all HRM assays were successful in Touriga Franca and Touriga Nacional samples. Regarding varietal quantification in blends, two HRM assays allowed the discrimination Touriga Nacional and Touriga Franca monovarietal samples and 90%/10% wine blends.