Evoluzione di alcune classi di polifenoli durante la maturazione dell’uva in diversi ambienti dell’Etna.

Abstract

Abstract Since mid-July to early October, Nerello Mascalese and Nerello Cappuccio grape cultivars ripening was followed in various sectors of the Mount Etna, featuring different microclimates and height, through the determination of the maturation curve of total anthocyanins, individual anthocyanins, hydroxycinnamic tartaric acid (HCTA) and individual flavonols. Even technological maturity of the grapes Nerello Mascalese had higher total acidity and pH lower than Nerello Cappuccio’s. A significant variability was found in different environments, in relation to the accumulation of sugars at the same date. The levels in HCTA, in flavonols and anthocyanins have been conditioned by the environment, from the date of collection and the variety. The profiles of the varietal HCTA and anthocyanins, however, have been conditioned by variety and environment less than those of flavonols probably because of differences during the individual metabolites’ synthesis. This peculiarity changes the speed of accumulation and the amount accumulated in different environments and different cultivars. The anthocyanic profiles of Nerello Mascalese and Nerello Cappuccio, discovered in previous studies, were confirmed in this work. They have not undergone significant changes during the grapes ripening in different environments. These two cultivars of Etna, codified from the tradition, have proved to be complementary for the contents of anthocyanins and tannins (evaluated through the determination of total flavonoids). Nerello Mascalese has attitudes to the synthesis of anthocyanins and tannins, respectively, smaller and more pronounced than Nerello Cappuccio. Finally, the curves of evolution of various parameters determined principal components analysis, have allowed to obtain important information on the influence of different vine environments of Etna, on the synthesis of metabolites of interest from quality grapes.