An electroanalytical approach has been developed for the identification and quantification of adulteration of white wine with apple juice and apple cider. After addition of LiClO4 as electrolyte and deoxygenation, the sample was analysed via cyclic voltammetry conducted on a screen-printed carbon electrode modified with gold nanoparticles. Cyclic voltammograms (CVs) of white wine samples displayed consistency regardless of their grape variety, mono-, bi- or multi-varietal status as well as geographical origin. In contrast, CVs of apple juice and apple cider exhibited similarities but were distinct from those of white wine. They were particularly characterized by the presence of a cathodic peak at about -0.50V, attributed to sugars and organic acids, predominantly malic acid. Subsequently, cyclic voltammograms were exported into data points and they were subjected to chemometric analysis. Principal Component Analysis effectively grouped samples into two clusters: white wine and apple juice/ apple cider. Class-modelling demonstrated the ability to detect adulteration in white wine samples, with a detection threshold of 5% v/v or lower, contingent upon the adulterant type (apple juice or apple cider). Partial Least Squares regression facilitated quantification of the adulteration level with acceptable accuracy. This approach is both cost-effective and straightforward, necessitating minimal sample preparation.
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