Determination of pyranoanthocyanine and malvidin-3-glucoside content in red wine of different vintages via LC-MS/ESI.

The qualification of pyranoanthocyanins vitisin A, vitisin B and pinotin A regarding indicator for wine age has been discussed controversially for several years. In the present study the amount of malvidin-3-glucoside and pyranoanthocyanin pigments in red wine in general and their suitability as tracer substances of wine age were examined via LC-ESI-MS. The total monomeric anthocyanin content was measured employing the pH differential method. For statistical data evaluation canonical discriminant analysis was applied to the data sets. 124 authentic wines from ten vintage years were analysed. Content of total monomeric anthocyanins and malvidin-3-glucoside in particular decreased over time, whereas neither the absolute nor the relative amount of pyranoanthocyanins related to monomeric anthocyanins showed definite correlation, hence leading to the conclusion that the analysis of pyranoanthocyanins does not allow deductions about the age of authentic wines.