Impact of chitosan treatment on the physico-chemical features of a sangiovese red wine

Context and Purpose of the study. Arbuscular mycorrhizal fungi (AMF) symbiosis with grapevines is a key component of vineyard ecosystems.

The selection, characterization, and recruitment of autochthonous yeast strains to drive the alcoholic fermentation process is a highly researched practice because it allows the differentiation of the organoleptic properties of wines, assuring process standardization, reducing fermentation times and improving the quality and safety of the final products [1, 2]. Sparkling wines are “special wines” obtained by secondary fermentation of the base wine. ​In the traditional method (Champenoise method), the re-fermentation takes place in the bottle after the addition to the base wine of the so-called tirage solution. This step, also known as prise de mousse, is followed by an aging period characterized by the release of compounds from the yeast cells that affect the organoleptic properties of the final product. The use of autochthonous yeasts as starter cultures for secondary fermentation is one of the recent innovations proposed to enhance and differentiate these wines’ sensory quality [3,4]. Apulia is the second Italian wine-producing region, and its productive chain is now going through a qualitative evolution by implementing the employment of innovative approaches to exalt the peculiar properties of regional wines.

Volatile Organic Compounds (VOCs) are responsible for the flavor and aroma of a wine. The sensory qualities of the wines depend not only on grape intrinsic characteristics, but also on extrinsic factors including the soil composition. Previous studies have shown that the application of pyrogenic carbon (biochar) can lead to a change in soil parameters. For that reason, one of the goals of the ERDF funded project «WoodUp» is the characterization and reutilization of the locally produced biochar for agricultural purposes.

The aim of this work was to analyze the variability in grape composition of the Tempranillo cultivar related to climatic conditions, in La Mancha Designation of Origin. Grape composition (sugar content, total acidity, pH, malic acid, and total and extractable anthocyanins) recorded during ripening, were analysed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The relationships between grape parameters with climatic variables related to temperature and to water deficits, referring different periods between phenological events along the growing cycle, were evaluated using regression analysis. High variability in grape composition was observed in the period analysed. Total acidity varied between 3.7 and 7.3 gL-1 while malic acid varied between 1.2 and 4 gL-1. The extractable anthocyanins ranged between 526 and 972 mgL-1, and total anthocyanins ranged between 922 and 1388 mgL-1, being the lowest values recorded in the hottest year (2017). Total acidity decreased 0.77 gL-1 for an increase of 100 GDD, while malic acid decrease in 0.42 gL-1 for the same GDD increase, being the period between veraison and harvest the one that seemed to have higher influence on acidity. In addition, it was confirmed that increasing water deficits decreased acidity. Total and extractable anthocyanins increased in about 210 and 105 mgL-1, respectively, with an increase of 100 GDD from veraison to harvest, and the increase in water deficits favour the increase of anthocyanins, both total and extractable anthocyanins. Total and extractable anthocyanins concentration increased in 35 and 22 mgL-1 per an increase of 10 mm in the water deficit. These results can be of interest to understand the potential changes that grapes composition may suffer under future warmer climates.

Context and purpose of the study. The genetic improvement of grapevines at the Edmund Mach Foundation (FEM) has evolved significantly since its inception, and its philosophy on sustainable viticulture through crossbreeding techniques aligns with the urgent need to reduce chemical use in agriculture.