Chemical description and organoleptic evaluation of Pinot noir wines from different parts of Italy: a three year investigation

Aim: this work gives a chemical description and sensory evaluation of several Pinot noir wines from different parts of Italy. For three subsequent years (2016-2018) the wine samples were submitted for in an Italian annual national Pinot noir competition aiming to define the best Pinot noir red wine from Italy. All of the wine samples were 3-years old (from vinification) at the moment they were analysed and evaluated; they were also registered for the competition the same year they were put on the market. Methods and results: all the wines were evaluated by a tasting panel composed of oenologists and wine experts, using the overall sensory quality as the descriptor. For the chemical screening, standard oenological chemical parameters (total acidity, colour, alcohol degree, total phenolic content, tannin indexes, etc.) and the content of the most abundant phenolic molecules by means of LC-MS analysis (triple quadrupole with internal standards) were determined. Pinot noir red wines produced from different parts of Italy showed a high variability for most standard wine chemical parameters considered, while the content of most single phenolic constituents was more retained and consistent with data from literature; except for t-resveratrol, which was significantly higher in our analyses, and delphinidin-3-glucoside, which was lower. Moreover, changes regarding the corresponding wines from the three vintages were noted. A correlation between the chemical parameters and the tasting panel results was also attempted. The results from a statistical analysis confirmed that alcoholic content, malvidin-3-glucoside and total anthocyanins had the highest positive impact on quality scores, while gallic acid, color tonality and total phenolic content had the highest negative. Conclusions: our results indicate that most wine producers have a conservative attitude with very slight differences found in the corresponding wines over the three years of investigation. The strong effects of agronomical, winemaking and ageing processes on chemical and sensorial features of Pinot noir red wines from Italy were also clearly shown. Compared to other monovarietal Pinot noir red wines from the same temperate area, single polyphenol content tended to be more retained than most standard chemical parameters. Significance and impact of the study: an overall quality assessment of a monovarietal wine, with its typicity as the main goal of a sensorial investigation, appears to be different from an objective quality assessment carried out by trained professional personnel using single standardised descriptors. Positive and negative correlations exist between sensorial judgement and chemical parameters, and the multiple linear regression model revealed relationships between the wine score and the set of the most important wine score description parameters.