Determinazione della frazione aromatica dei vini, quale strumento per-la valorizzazione del territorio viticolo

Many compounds of interest in wine are difficult to analyze since they are present in very small quantities or they are unstable. The need for reliable data led scientists to develop complex method in order to overcome the analytical difficulties and provide accurate quantitative data for grape or wine characterization.

Yield monitoring can provide the winegrowers with information for precise production inputs during the season, thereby, ensuring the best possible harvest. Yield estimation is currently achieved through an intensive process that is destructive and time-consuming. However, remote sensing provides a group of proximal technologies and techniques for a non-destructive and less time-consuming method for yield monitoring.The objective of this study was to analyse three different approaches, for measuring grapevine yield close to harvest.

Sulphur dioxide (SO2) is a well-established preservative in the wine industry. Its ability to act in different stages of the process as an antioxidant and an antiseptic as main characteristics makes it versatile. However, the need for its reduction or even its replacement has been increasing by the regulatory authorities as well as by the final consumer. To understand the impact of SO2 during ageing on volatile organic compounds (VOCs) and amino acids (AAs) profiles, two white wines (one varietal and one blend) were aged under the same conditions, in the presence of different doses of SO2. After fermentation (t=0), 0, 30, 60, 90 and 120 mg/L of SO2 were applied, wines were kept over lees for 3 months (t=3), then were bottled after 3 (t=6) and 9 (t=12) months.

In the context of global warming, water scarcity is becoming an increasing issue worldwide. However, the reference method to characterize vine water deficit is based on water potential measurement, which is a destructive and discontinuous method. The current climatic context emphasizes the need for more precise and more continuous vineyard water use measurements in order to optimize irrigation and vine water deficit monitoring.

Color is one of the key elements in the marketing of rosé wines[1]. Their broad range of color is due to the presence of red pigments (i.e. anthocyanins and their derivatives) and yellow pigments, likely including polyphenol oxidation products. Clarifying agents are widely used in the winemaking industry to enhance wine stability and to modulate wine color by binding and precipitating polyphenols[2]. During this study, the impact of four different fining agents (i.e. two vegetal proteins, potatoe and pea proteins, an animal protein, casein, and a synthetic polymer, polyvinylpolypyrrolidone, PVPP) on Syrah Rose wine color and phenolic composition (especially pigments) was investigated. Color was characterized by spectrophotometry analysis using the CIELab system in addition to absorbance data. Fining using PVPP had the highest impact on redness (a*) and lightness (L*) parameters, whereas patatin strongly reduced the yellow component (b*) of the wine color. In parallel, the concentration of 125 phenolic compounds including 85 anthocyanins and derived pigments was determined by Ultra High Performance Liquid Chromatography coupled to elestrospray ionisaion triple-quadrupole Mass Spectrometry (UHPLC-QqQ-ESI-MS) in the Multiple Reaction Monitoring mode[3] .