applicazione dei metodi isotopici e dell’analisi sensoriale negli studi sull’origine dei vini

The objective of the present work is to assess yeast effects on the development of wine varietal aroma throughout aging and on wine longevity. Three independent experiments were carried out; two fermenting semi-synthetic musts fortified with polyphenols and aroma precursors extracted from Tempranillo (1) or Albariño (2) grapes and with synthetic precursors of polyfunctional mercaptans (PFMs), and a third in which a must, mixture of 6 different grape varieties was used. In all cases, fermentations were carried out by different Saccharomyces cerevisiae strains and one S. kudriavzevii, and the obtained wines were further submitted to anoxic accelerated aging to reproduce bottle aging. The volatile profile of the wines was analyzed using several chromatographic procedures, in order to provide a comprehensive evaluation of wine aroma. Aroma compounds analyzed included fermentation volatile metabolites, grape-derived aroma compounds including PFMs, and Strecker aldehydes (SA). Results revealed that the effects of yeast on wine aroma throughout its self-life extend along three main axes: 1. A direct or indirect action on primary varietal aroma and on its evolution during wine aging. 2. The direct production of SA during fermentation and/or their delayed formation by producing the required reagents (amino acids + dicarbonyls) for Strecker degradation during anoxic aging. 3. Producing acids (leucidic, branched acids) precursors to fruity esters. More specifically, and leaving aside the infrequent de novo formation, the action of the different strains of yeast on primary varietal aroma takes four different forms: 1.- Speeding the hydrolysis of aroma precursors, which leads to early aroma formation without changing the amount of aroma formed. In the case of labile molecules, such as linalool, the enhancement of young wine aroma implies a short-living wine. 2.- Metabolizing the aroma precursor, reducing the amounts of aroma formed, which can be of advantage for negative aroma compounds, such as TDN or guaiacol; 3.- Transforming grape components into aroma precursors, increasing the amounts of aroma formed, as for ethyl cinnamate, leucidic acid or vinylphenols; 4.- Forming reactive species such as vinylphenols able to destroy varietal polyfunctional mercaptans. Overall, it can be concluded that the yeast carrying alcoholic fermentation not only influences fermentative wine aroma but also affects to the wine varietal aroma, to its evolution during aging and to the development of oxidative off-odors

In the concept of sustainable viticulture proposed by the OIV, it can be noted that enhancing terroir is also one measure of sustainability. Thus, the territorial approach may offer an interesting viewpoint from which to consider this issue in a multi-perspective way.

Bioprotection, leveraging beneficial microorganisms, has emerged as a sustainable approach to modern winemaking, minimizing reliance on chemical preservatives like as sulfur dioxide (SO₂).

The trial aims to improve the protection and management of the soil, the well-being of the plant and the quality of production in the wine supply chain organic and biodynamic, using an innovative product “ZEOWINE” resulting from the composting of waste of the wine and zeolite supply chain.

Recent EU regulations allow the use of carboxymethylcellulose (CMC) as a stabilization agent in wine. We tested CMC in bases for sparkling wines, which must be stabilized before the second fermentation that raises alcohol concentration by 1,5%.