Rapid HPLC/DAD/MS method to determine phenolic acids, glycoalkaloids and anthocyanins in pigmented potatoes (Solanum tuberosum L.) and correlations with variety and geographical origin

In the present study a single procedure to simultaneously determine phenolic acids, anthocyanins and glycoalkaloids was applied in 13 cultivars all with pigmented peel. A single exhaustive extraction for the three classes of compounds and a single analytical HPLC method were proposed. From a quantitative point of view, the RSD values from intra and inter-day assays were <5.7% for the three classes of metabolites. Concerning the influence of different growing areas, the highest anthocyanin concentrations and the lower glycolkaloid content in the pulp were found in tubers from the geographical area at 1000 m a.s.l in southern Italy. Principal Component Analysis (PCA) did not allow the discrimination of different clusters when applied to phenolic acids, while the scatterplot obtained with regard to the anthocyanin profiles clustered the cultivars into five distinct groups. These pigments can be proposed as “fingerprints” of the cultivar.