Diversity of Italian red wines: A study by enological parameters, color, and phenolic indices

An extensive survey was conducted on 110 Italian monovarietal red wines from a single vintage to determine their standard compositional, color, and phenolic characteristics, analysing more than 35 parameters evaluated through methods commonly used in the wine industry. 'Primitivo' achieved the highest average alcohol strength (15.4% v/v) and dry extract values, while 'Cannonau' showed the lowest total acidity. 'Corvina' had the lowest phenolic content (1065 mg/L by Folin-Ciocalteu assay), remarkably different from the highest found in 'Sagrantino' (3578 mg/L), the latter being also the richest variety in both proanthocyanidins and vanillin-reactive flavanols. 'Teroldego' wines were the richest in both total and monomeric anthocyanins (702 and 315 mg/L, respectively), followed by 'Aglianico' and 'Raboso Piave', while 'Corvina', 'Nebbiolo', and 'Nerello Mascalese' were the poorest. 'Montepulciano' and 'Sangiovese' showed intermediate values for the majority of the parameters analyzed. A multivariate PCA-DA approach allowed achieving both a classification of the different wines as well as the discrimination of 'Sangiovese' wines produced in two regions (Emilia Romagna and Toscana) that returned a 42-66% success rate depending on the zone considered. Taking into account the number and diversity of the wines analyzed, a correlation study helped in better understanding the underlying relations between the most common and widespread analytical techniques for phenolic and color determinations.

Selection of indigenous yeast strains for the production of sparkling wines from native Apulian grape varieties

We report the first polyphasic characterization of native Saccharomyces cerevisiae in order to select candidate strains for the design of starter cultures tailored for Apulian sparkling wines obtained from local grape variety. In addition, it is the first survey in our region that propose the selection of autochthonous starter cultures for sparkling wine i) including a preliminary tailored genotypic and technological screening, and ii) monitoring analytical contribution during secondary fermentation in terms of volatile compounds (VOCs). Furthermore, we exploit the potential contribute of autochthonous cultures throughout the productive chain, including the possible improvement of base wine. One representative strain from each cluster was characterized i) for tolerance to abiotic and biotic stressors peculiar of sparkling wine fermentation, ii) for the performances in base wine production, and iii) for the aptitudes to promote in-bottle secondary fermentation in white and rosé sparkling wines, both obtained from Apulian grape varieties. Genetic characterization led to group 164 S. cerevisiae in 16 genetic clusters based on interdelta profiles. Stress tolerance assays shown a certain correlation with fermentative attitude. Our evidences demonstrated a different fermentative behavior and release of VOCs of the different strains in association with primary and secondary fermentations and as function of wine and rosé sparkling wine. Furthermore, performances in white/rosé sparkling wines have been found to be strain-dependent characters. Overall, we propose different strains as biotechnological resources suitable to improve the quality of regional sparkling wines and to provide a driver of innovation/segmentation in the market.