Usefulness of excitation-emission fluorescence spectralprint combined with chemometrics for authentication of PDO fortified wines

Abstract

Fortified wines covered by a Protected Designation of Origin (PDO) are high-quality products appreciated by consumers, whose diversity has increased in recent years, leading to an increased vulnerability to fraud. In this work, for the first time, an excitation-emission fluorescence spectroscopy method combined with two chemometric approaches was developed for the characterization and authentication of PDO fortified wines. A visual assessment of fluorescence landscapes pointed out different trends. The excitation-emission matrix (EEM) was decomposed using Parallel Factor Analysis (PARAFAC) for the extraction of potential fluorophores, or unfolded, and then, the resulting matrices were subjected to Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Both approaches were able to discriminate the wine type within each PDO, the PDO within a wine type, and the production process. The proposed analytical and chemometric tools could be used as an alternative control method for a rapid screening of Spanish PDO fortified wines.