Exploration of the anthocyanin and proanthocyanidin profile of Greek red grape skins belonging to Vradiano, Limnio, and Kotsifali cultivars, analyzed by a novel LC‐QTOF‐MS/MS method

Introduction Winegrape varieties Kotsifali, Limnio, and Vradiano Objective The aim of this study was to develop a liquid chromatographic quadrupole time‐of‐flight tandem mass spectrometric (LC‐QTOF‐MS/MS) method for the investigation of the anthocyanin and proanthocyanidin content of Greek grape varieties employing target and suspect screening strategies. Methodology A novel LC‐QTOF‐MS/MS method was developed and validated to assess the anthocyanin content of Kotsifali, Limnio, and Vradiano grape varieties. Sixteen grape samples were collected from the main growing areas of each variety in Greece. The influence of the grape variety on the anthocyanin and proanthocyanidin composition of three Greek winegrapes was investigated using chemometrics. Results Excellent linearity (R2 > 0.99) was achieved for all the target analytes, and recoveries ranged between 90.1% and 119.1%. The limits of quantification (LOQs) and limits of detection (LODs) were calculated over the range of 0.020–0.40 mg/g and 0.010–0.13 mg/g, respectively. The RSD% was lower than 9.1% and 7.3% for intra‐day and inter‐day studies, respectively, indicating satisfactory trueness and precision. Target and suspect screening resulted in the identification of 5 and 26 anthocyanins, respectively. Conclusions Kotsifali variety exhibited a higher concentration of anthocyanins compared with Vradiano and Limnio. Higher levels of mean degree of polymerization (mDp) and different percentage levels of prodelphinidins (%P) were established among the varieties. A novel LC‐QTOF‐MS/MS method was developed and validated for the analysis of anthocyanins and proanthocyanidins in Greek grape varieties: Kotsifali, Limnio, and Vradiano. The method exhibited excellent linearity (R2 〉 0.99) and high recoveries (90.1–130.8%). Limits of quantification (LOQs) and limits of detection (LODs) were calculated over the ranges 0.020–0.40 mg/g and 0.010–0.13 mg/g, respectively. Chemometrics revealed the effects of grape variety on anthocyanin and proanthocyanidin composition. Kotsifali exhibited the highest anthocyanin levels, while different levels of proanthocyanidin composition were found among the varieties.